Grice's Dictionary -- in five volumes, vol. IV.

omega, the last letter of the Grecian alphabet w. Following Cantor 18451911, it is used in lowercase as a proper name for the first infinite ordinal number, which is the ordinal of the natural ordering of the set of finite ordinals. By extension it is also used as a proper name for the set of finite ordinals itself or even for the set of natural numbers. Following Gödel 190678, it is used as a prefix in names of various logical properties of sets of sentences, most notably omega-completeness and omega-consistency. Omega-completeness, in the original sense due to Tarski, is a syntactical property of sets of sentences in a formal arithmetic language involving a symbol ‘0’ for the number zero and a symbol ‘s’ for the so-called successor function, resulting in each natural number being named by an expression, called a numeral, in the following series: ‘0’, ‘s0’, ‘ss0’, and so on. For example, five is denoted by ‘sssss0’. A set of sentences is said to be omegacomplete if it deductively yields every universal sentence all of whose singular instances it yields. In this framework, as usual, every universal sentence, ‘for every n, n has P’ yields each and every one of its singular instances, ‘0 has P’, ‘s0 has P’, ‘ss0 has P’, etc. However, as had been known by logicians at least since the Middle Ages, the converse is not true, i.e., it is not in general the case that a universal sentence is deducible from the set of its singular instances. Thus one should not expect to find omega-completeness except in exceptional sets. The set of all true sentences of arithmetic is such an exceptional set; the reason is the semantic fact that every universal sentence whether or not in arithmetic is materially equivalent to the set of all its singular instances. A set of sentences that is not omega-complete is Ockham’s razor omega 629    629 said to be omega-incomplete. The existence of omega-incomplete sets of sentences is a phenomenon at the core of the 1931 Gödel incompleteness result, which shows that every “effective” axiom set for arithmetic is omega-incomplete and thus has as theorems all singular instances of a universal sentence that is not one of its theorems. Although this is a remarkable fact, the existence of omega-incomplete sets per se is far from remarkable, as suggested above. In fact, the empty set and equivalently the set of all tautologies are omega-incomplete because each yields all singular instances of the non-tautological formal sentence, here called FS, that expresses the proposition that every number is either zero or a successor. Omega-consistency belongs to a set that does not yield the negation of any universal sentence all of whose singular instances it yields. A set that is not omega-consistent is said to be omega-inconsistent. Omega-inconsistency of course implies consistency in the ordinary sense; but it is easy to find consistent sets that are not omega-consistent, e.g., the set whose only member is the negation of the formal sentence FS mentioned above. Corresponding to the syntactical properties just mentioned there are analogous semantic properties whose definitions are obtained by substituting ‘semantically implies’ for ‘deductively yields’. The Grecian letter omega and its English name have many other uses in modern logic. Carnap introduced a non-effective, non-logical rule, called the omega rule, for “inferring” a universal sentence from its singular instances; adding the omega rule to a standard axiomatization of arithmetic produces a complete but non-effective axiomatization. An omega-valued logic is a many-valued logic whose set of truth-values is or is the same size as the set of natural numbers. 

One-many problem, also called one-and-many problem, the question whether all things are one or many. According to both Plato and Aristotle this was the central question for pre-Socratic philosophers. Those who answered “one,” the monists, ascribed to all things a single nature such as water, air, or oneness itself. They appear not to have been troubled by the notion that numerically many things would have this one nature. The pluralists, on the other hand, distinguished many principles or many types of principles, though they also maintained the unity of each principle. Some monists understood the unity of all things as a denial of motion, and some pluralists advanced their view as a way of refuting this denial. To judge from our sources, early Grecian metaphysics revolved around the problem of the one and the many. In the modern period the dispute between monists and pluralists centered on the question whether mind and matter constitute one or two substances and, if one, what its nature is. 

one over many, a universal; especially, a Platonic Form. According to Plato, if there are, e.g., many large things, there must be some one largeness itself in respect of which they are large; this “one over many” hen epi pollon is an intelligible entity, a Form, in contrast with the sensible many. Plato himself recognizes difficulties explaining how the one character can be present to the many and why the one and the many do not together constitute still another many e.g., Parmenides 131a133b. Aristotle’s sustained critique of Plato’s Forms Metaphysics A 9, Z 1315 includes these and other problems, and it is he, more than Plato, who regularly uses ‘one over many’ to refer to Platonic Forms. 

ontological commitment, the object or objects common to the ontology fulfilling some regimented theory a term fashioned by Quine. The ontology of a regimented theory consists in the objects the theory assumes there to be. In order to show that a theory assumes a given object, or objects of a given class, we must show that the theory would be true only if that object existed, or if that class is not empty. This can be shown in two different but equivalent ways: if the notation of the theory contains the existential quantifier ‘Ex’ of first-order predicate logic, then the theory is shown to assume a given object, or objects of a given class, provided that object is required among the values of the bound variables, or additionally is required among the values of the domain of a given predicate, in order for the theory to be true. Thus, if the theory entails the sentence ‘Exx is a dog’, then the values over which the bound variable ‘x’ ranges must include at least one dog, in order for the theory to be true. Alternatively, if the notation of the theory contains for each predicate a complementary predicate, then the theory assumes a given object, or objects of a given class, provided some predicate is required to be true of that object, in order for the theory to be true. Thus, if the theory contains the predicate ‘is a dog’, then the extension of ‘is a dog’ cannot be empty, if the theory is to be true. However, it is possible for different, even mutually exclusive, ontologies to fulfill a theory equally well. Thus, an ontology containing collies to the exclusion of spaniels and one containing spaniels to the exclusion of collies might each fulfill a theory that entails ‘Ex x is a dog’. It follows that some of the objects a theory assumes in its ontology may not be among those to which the theory is ontologically committed. A theory is ontologically committed to a given object only if that object is common to all of the ontologies fulfilling the theory. And the theory is ontologically committed to objects of a given class provided that class is not empty according to each of the ontologies fulfilling the theory. 

open formula, also called open sentence, a sentence with a free occurrence of a variable. A closed sentence, sometimes called a statement, has no free occurrences of variables. In a language whose only variable-binding operators are quantifiers, an occurrence of a variable in a formula is bound provided that occurrence either is within the scope of a quantifier employing that variable or is the occurrence in that quantifier. An occurrence of a variable in a formula is free provided it is not bound. The formula ‘xy  O’ is open because both ‘x’ and ‘y’ occur as free variables. In ‘For some real number y, xy  O’, no occurrence of ‘y’ is free; but the occurrence of ‘x’ is free, so the formula is open. The sentence ‘For every real number x, for some real number y, xy  O’ is closed, since none of the variables occur free. Semantically, an open formula such as ‘xy  0’ is neither true nor false but rather true of or false of each assignment of values to its free-occurring variables. For example, ‘xy  0’ is true of each assignment of two positive or two negative real numbers to ‘x’ and to ‘y’ and it is false of each assignment of 0 to either and false at each assignment of a positive real to one of the variables and a negative to the other. 

open texture, the possibility of vagueness. Frieone-way reduction sentence open texture 631    631 drich Waismann “Verifiability,” Proceedings of the Aristotelian Society, 1945 introduced the concept, claiming that open texture is a universal property of empirical terms. Waismann claimed that an inexhaustible source of vagueness remains even after measures are taken to make an expression precise. His grounds were, first, that there are an indefinite number of possibilities for which it is indeterminate whether the expression applies i.e., for which the expression is vague. There is, e.g., no definite answer whether a catlike creature that repeatedly vanishes into thin air, then reappears, is a cat. Waismann’s explanation is that when we define an empirical term, we frame criteria of its applicability only for foreseeable circumstances. Not all possible situations in which we may use the term, however, can be foreseen. Thus, in unanticipated circumstances, real or merely possible, a term’s criteria of applicability may yield no definite answer to whether it applies. Second, even for terms such as ‘gold’, for which there are several precise criteria of application specific gravity, X-ray spectrograph, solubility in aqua regia, applying different criteria can yield divergent verdicts, the result being vagueness. Waismann uses the concept of open texture to explain why experiential statements are not conclusively verifiable, and why phenomenalist attempts to translate material object statements fail. 

operationalism, a program in philosophy of science that aims to interpret scientific concepts via experimental procedures and observational outcomes. P. W. Bridgman introduced the terminology when he required that theoretical concepts be identified with the operations used to measure them. Logical positivism’s criteria of cognitive significance incorporated the notion: Bridgman’s operationalism was assimilated to the positivistic requirement that theoretical terms T be explicitly defined via logically equivalent to directly observable conditions O. Explicit definitions failed to accommodate alternative measurement procedures for the same concept, and so were replaced by reduction sentences that partially defined individual concepts in observational terms via sentences such as ‘Under observable circumstances C, x is T if and only if O’. Later this was weakened to allow ensembles of theoretical concepts to be partially defined via interpretative systems specifying collective observable effects of the concepts rather than effects peculiar to single concepts. These cognitive significance notions were incorporated into various behaviorisms, although the term ‘operational definition’ is rarely used by scientists in Bridgman’s or the explicit definition senses: intervening variables are theoretical concepts defined via reduction sentences and hypothetical constructs are definable by interpretative systems but not reduction sentences. In scientific contexts observable terms often are called dependent or independent variables. When, as in science, the concepts in theoretical assertions are only partially defined, observational consequences do not exhaust their content, and so observational data underdetermines the truth of such assertions in the sense that more than one theoretical assertion will be compatible with maximal observational data. 

operator, a one-place sentential connective; i.e., an expression that may be prefixed to an open or closed sentence to produce, respectively, a new open or closed sentence. Thus ‘it is not the case that’ is a truth-functional operator. The most thoroughly investigated operators are the intensional ones; an intensional operator O, when prefixed to an open or closed sentence E, produces an open or closed sentence OE, whose extension is determined not by the extension of E but by some other property of E, which varies with the choice of O. For example, the extension of a closed sentence is its truth-value A, but if the modal operator ‘it is necessary that’ is prefixed to A, the extension of the result depends on whether A’s extension belongs to it necessarily or contingently. This property of A is usually modeled by assigning to A a subset X of a domain of possible worlds W. If X % W then ‘it is necessary that A’ is true, but if X is a proper subset of W, it is false. Another example involves the epistemic operator ‘it is plausible that’. Since a true sentence may be either plausible or implausible, the truth-value of ‘it is plausible that A’ is not fixed by the truth-value of A, but rather by the body of evidence that supports A relative to a thinker in a given context. This may also be modeled in a possible worlds framework, by operant conditioning operator 632    632 stipulating, for each world, which worlds, if any, are plausible relative to it. The topic of intensional operators is controversial, and it is even disputable whether standard examples really are operators at the correct level of logical form. For instance, it can be argued that ‘it is necessary that’, upon analysis, turns out to be a universal quantifier over possible worlds, or a predicate of expressions. On the former view, instead of ‘it is necessary that A’ we should write ‘for every possible world w, Aw’, and, on the latter, ‘A is necessarily true’. 

operator theory of adverbs, a theory that treats adverbs and other predicate modifiers as predicate-forming operators on predicates. The theory expands the syntax of first-order logic by adding operators of various degrees, and makes corresponding additions to the semantics. Romane Clark, Terence Parsons, and Richard Montague with Hans Kamp developed the theory independently in the early 1970s. For example: ‘John runs quickly through the kitchen’ contains a simple one-place predicate, ‘runs’ applied to John; a zero-place operator, ‘quickly’, and a one-place operator, ‘through ’ with ‘the kitchen’ filling its place. The logical form of the sentence becomes [O1 1a [O2 0 [Pb]]], which can be read: [through the kitchen [quickly [runs John]]]. Semantically ‘quickly’ will be associated with an operation that takes us from the extension of ‘runs’ to a subset of that extension. ‘John runs quickly’ will imply ‘John runs’. ‘Through the kitchen’ and other operators are handled similarly. The wide variety of predicate modifiers complicates the inferential conditions and semantics of the operators. ‘John is finally done’ implies ‘John is done’. ‘John is nearly done’ implies ‘John is not done’. Clark tries to distinguish various types of predicate modifiers and provides a different semantic analysis for operators of different sorts. The theory can easily characterize syntactic aspects of predicate modifier iteration. In addition, after being modified the original predicates remain as predicates, and maintain their original degree. Further, there is no need to force John’s running into subject position as might be the case if we try to make ‘quickly’ an ordinary predicate. T.J.D. O-proposition.

order, the level of a logic as determined by the type of entity over which the free variables of that logic range. Entities of the lowest type, usually called type O, are known as individuals, and entities of higher type are constructed from entities of lower type. For example, type 1 entities are i functions from individuals or n-tuples of individuals to individuals, and ii n-place relations on individuals. First-order logic is that logic whose variables range over individuals, and a model for first-order logic includes a domain of individuals. The other logics are known as higher-order logics, and the first of these is second-order logic, in which there are variables that range over type 1 entities. In a model for second-order logic, the first-order domain determines the second-order domain. For every sentence to have a definite truth-value, only totally defined functions are allowed in the range of second-order function variables, so these variables range over the collection of total functions from n-tuples of individuals to individuals, for every value of n. The second-order predicate variables range over all subsets of n-tuples of individuals. Thus if D is the domain of individuals of a model, the type 1 entities are the union of the two sets {X: Dn: X 0 Dn$D}, {X: Dn: X 0 Dn}. Quantifiers may bind second-order variables and are subject to introduction and elimination rules. Thus whereas in first-order logic one may infer ‘Someone is wise, ‘DxWx’, from ‘Socrates is wise’, ‘Ws’, in second-order logic one may also infer ‘there is something that Socrates is’, ‘DXXs’. The step from first- to second-order logic iterates: in general, type n entities are the domain of n ! 1thorder variables in n ! 1th order logic, and the whole hierarchy is known as the theory of types.

operator, deontic ordered pair 633    633 ordering, an arrangement of the elements of a set so that some of them come before others. If X is a set, it is useful to identify an ordering R of X with a subset R of X$X, the set of all ordered pairs with members in X. If ‹ x,y  1 R then x comes before y in the ordering of X by R, and if ‹ x,y  2 R and ‹ y,x  2 R, then x and y are incomparable. Orders on X are therefore relations on X, since a relation on a set X is any subset of X $ X. Some minimal conditions a relation must meet to be an ordering are i reflexivity: ExRxx; ii antisymmetry: ExEyRxy & Ryx / x % y; and iii transitivity: ExEyEzRxy & Ryz / Rxz. A relation meeting these three conditions is known as a partial order also less commonly called a semi-order, and if reflexivity is replaced by irreflexivity, Ex-Rxx, as a strict partial order. Other orders are strengthenings of these. Thus a tree-ordering of X is a partial order with a distinguished root element a, i.e. ExRax, and that satisfies the backward linearity condition that from any element there is a unique path back to a: ExEyEzRyx & Rzx / Ryz 7 Rzy. A total order on X is a partial order satisfying the connectedness requirement: ExEyRxy 7 Ryx. Total orderings are sometimes known as strict linear orderings, contrasting with weak linear orderings, in which the requirement of antisymmetry is dropped. The natural number line in its usual order is a strict linear order; a weak linear ordering of a set X is a strict linear order of levels on which various members of X may be found, while adding antisymmetry means that each level contains only one member. Two other important orders are dense partial or total orders, in which, between any two elements, there is a third; and well-orders. A set X is said to be well-ordered by R if R is total and every non-empty subset of Y of X has an R-least member: EY 0 X[Y & / / Dz 1 YEw 1 YRzw]. Well-ordering rules out infinite descending sequences, while a strict well-ordering, which is irreflexive rather than reflexive, rules out loops. The best-known example is the membership relation of axiomatic set theory, in which there are no loops such as x 1 y 1 x or x 1 x, and no infinite descending chains . . . x2 1 x1 1 x0. 

order type omega, in mathematics, the order type of the infinite set of natural numbers. The last letter of the Grecian alphabet, w, is used to denote this order type; w is thus the first infinite ordinal number. It can be defined as the set of all finite ordinal numbers ordered by magnitude; that is, w % {0,1,2,3 . . . }. A set has order type w provided it is denumerably infinite, has a first element but not a last element, has for each element a unique successor, and has just one element with no immediate predecessor. The set of even numbers ordered by magnitude, {2,4,6,8 . . . }, is of order type w. The set of natural numbers listing first all even numbers and then all odd numbers, {2,4,6,8 . . .; 1,3,5,7 . . . }, is not of order type w, since it has two elements, 1 and 2, with no immediate predecessor. The set of negative integers ordered by magnitude, { . . . 3,2,1}, is also not of order type w, since it has no first element. V.K. ordinal logic, any means of associating effectively and uniformly a logic in the sense of a formal axiomatic system Sa with each constructive ordinal notation a. This notion and term for it was introduced by Alan Turing in his paper “Systems of Logic Based on Ordinals” 1939. Turing’s aim was to try to overcome the incompleteness of formal systems discovered by Gödel in 1931, by means of the transfinitely iterated, successive adjunction of unprovable but correct principles. For example, according to Gödel’s second incompleteness theorem, for each effectively presented formal system S containing a modicum of elementary number theory, if S is consistent then S does not prove the purely universal arithmetical proposition Cons expressing the consistency of S via the Gödelnumbering of symbolic expressions, even though Cons is correct. However, it may be that the result S’ of adjoining Cons to S is inconsistent. This will not happen if every purely existential statement provable in S is correct; call this condition E-C. Then if S satisfies E-C, so also does S; % S ! Cons ; now S; is still incomplete by Gödel’s theorem, though it is more complete than S. Clearly the passage from S to S; can be iterated any finite number of times, beginning with any S0 satisfying E-C, to form S1 % S; 0, S2 % S; 1, etc. But this procedure can also be extended into the transfinite, by taking Sw to be the union of the systems Sn for n % 0,1, 2 . . . and then Sw!1 % S;w, Sw!2 % S;w!1, etc.; condition EC is preserved throughout. To see how far this and other effective extension procedures of any effectively presented system S to another S; can be iterated into the transfinite, one needs the notion of the set O of constructive ordinal notations, due to Alonzo Church and Stephen C. Kleene in 1936. O is a set ordering ordinal logic 634    634 of natural numbers, and each a in O denotes an ordinal a, written as KaK. There is in O a notation for 0, and with each a in O is associated a notation sca in O with KscaK % KaK ! 1; finally, if f is a number of an effective function {f} such that for each n, {f}n % an is in O and KanK < Kan!1K, then we have a notation øf in O with KøfK % limnKanK. For quite general effective extension procedures of S to S; and for any given S0, one can associate with each a in O a formal system Sa satisfying Ssca % S;a and Søf % the union of the S{f}n for n % 0,1, 2. . . . However, as there might be many notations for each constructive ordinal, this ordinal logic need not be invariant, in the sense that one need not have: if KaK % KbK then Sa and Sb have the same consequences. Turing proved that an ordinal logic cannot be both complete for true purely universal statements and invariant. Using an extension procedure by certain proof-theoretic reflection principles, he constructed an ordinal logic that is complete for true purely universal statements, hence not invariant. The history of this and later work on ordinal logics is traced by the undersigned in “Turing in the Land of Oz,” in The Universal Turing Machine: A Half Century Survey, edited by Rolf Herken [1988]. 

ordinary language philosophy, a loosely structured philosophical movement holding that the significance of concepts, including those central to traditional philosophy  e.g., the concepts of truth and knowledge  is fixed by linguistic practice. Philosophers, then, must be attuned to the actual uses of words associated with these concepts. The movement enjoyed considerable prominence chiefly among English-speaking philosophers between the mid-1940s and the early 1960s. It was initially inspired by the work of Wittgenstein, and later by John Wisdom, Gilbert Ryle, Norman Malcolm, and J. L. Austin, though its roots go back at least to Moore and arguably to Socrates. Ordinary language philosophers do not mean to suggest that, to discover what truth is, we are to poll our fellow speakers or consult dictionaries. Rather, we are to ask how the word ‘truth’ functions in everyday, nonphilosophical settings. A philosopher whose theory of truth is at odds with ordinary usage has simply misidentified the concept. Philosophical error, ironically, was thought by Wittgenstein to arise from our “bewitchment” by language. When engaging in philosophy, we may easily be misled by superficial linguistic similarities. We suppose minds to be special sorts of entity, for instance, in part because of grammatical parallels between ‘mind’ and ‘body’. When we fail to discover any entity that might plausibly count as a mind, we conclude that minds must be nonphysical entities. The cure requires that we remind ourselves how ‘mind’ and its cognates are actually used by ordinary speakers. 

organic, having parts that are organized and interrelated in a way that is the same as, or analogous to, the way in which the parts of a living animal or other biological organism are organized and interrelated. Thus, an organic unity or organic whole is a whole that is organic in the above sense. These terms are primarily used of entities that are not literally organisms but are supposedly analogous to them. Among the applications of the concept of an organic unity are: to works of art, to the state e.g., by Hegel, and to the universe as a whole e.g., in absolute idealism. The principal element in the concept is perhaps the notion of an entity whose parts cannot be understood except by reference to their contribution to the whole entity. Thus to describe something as an organic unity is typically to imply that its properties cannot be given a reductive explanation in terms of those of its parts; rather, at least some of the properties of the parts must themselves be explained by reference to the properties of the whole. Hence it usually involves a form of holism. Other features sometimes attributed to organic unities include a mutual dependence between the existence of the parts and that of the whole and the need for a teleological explanation of properties of the parts in terms of some end or purpose associated with the whole. To what extent these characteristics belong to genuine biological organisms is disputed. 

organicism, a theory that applies the notion of an organic unity, especially to things that are not literally organisms. G. E. Moore, in Principia Ethica, proposed a principle of organic unities, concerning intrinsic value: the intrinsic value of a whole need not be equivalent to the sum of the intrinsic values of its parts. Moore applies the principle in arguing that there is no systematic relation between ordinal utility organicism 635    635 the intrinsic value of an element of a complex whole and the difference that the presence of that element makes to the value of the whole. E.g., he holds that although a situation in which someone experiences pleasure in the contemplation of a beautiful object has far greater intrinsic goodness than a situation in which the person contemplates the same object without feeling pleasure, this does not mean that the pleasure itself has much intrinsic value.

organism, a carbon-based living thing or substance, e.g., a paramecium, a tree, or an ant. Alternatively, ‘organism’ can mean a hypothetical living thing of another natural kind, e.g., a silicon-based living thing. Defining conditions of a carbon-based living thing, x, are as follows. 1 x has a layer made of m-molecules, i.e., carbonbased macromolecules of repeated units that have a high capacity for selective reactions with other similar molecules. x can absorb and excrete through this layer. 2 x can metabolize m-molecules. 3 x can synthesize m-molecular parts of x by means of activities of a proper part of x that is a nuclear molecule, i.e., an m-molecule that can copy itself. 4 x can exercise the foregoing capacities in such a way that the corresponding activities are causally interrelated as follows: x’s absorption and excretion causally contribute to x’s metabolism; these processes jointly causally contribute to x’s synthesizing; and x’s synthesizing causally contributes to x’s absorption, excretion, and metabolism. 5 x belongs to a natural kind of compound physical substance that can have a member, y, such that: y has a proper part, z; z is a nuclear molecule; and y reproduces by means of z’s copying itself. 6 x is not possibly a proper part of something that satisfies 16. The last condition expresses the independence and autonomy of an organism. For example, a part of an organism, e.g., a heart cell, is not an organism. It also follows that a colony of organisms, e.g., a colony of ants, is not an organism. 

Origen A.D. 185253, Christian theologian and biblical scholar in the Alexandrian church. Born in Egypt, he became head of the catechetical school in Alexandria. Like his mentor, Clement of Alexandria, he was influenced by Middle Platonism. His principal works were Hexapla, On First Principles, and Contra Celsum. The Hexapla, little of which survives, consisted of six Hebrew and two Grecian versions of the Old Testament with Origen’s commentary. On First Principles sets forth the most systematic Christian theology of the early church, including some doctrines subsequently declared heretical, such as the subordination of the Son “a secondary god” and Spirit to the Father, preexisting human souls but not their transmigration, and a premundane fall from grace of each human soul. The most famous of his views was the notion of apocatastasis, universal salvation, the universal restoration of all creation to God in which evil is defeated and the devil and his minions repent of their sins. He interpreted hell as a temporary purgatory in which impure souls were purified and made ready for heaven. His notion of subordination of the Son of God to the Father was condemned by the church in 533. Origen’s Contra Celsum is the first sustained work in Christian apologetics. It defends Christianity before the pagan world. Origen was a leading exponent of the allegorical interpretation of the Scriptures, holding that the text had three levels of meaning corresponding to the three parts of human nature: body, soul, and spirit. The first was the historical sense, sufficient for simple people; the second was the moral sense; and the third was the mystical sense, open only to the deepest souls. L.P.P. original position.

Orphism, a religious movement in ancient Greece that may have influenced Plato and some of the pre-Socratics. Neither the nature of the movement nor the scope of its influence is adequately understood: ancient sources and modern scholars tend to confuse Orphism with Pythagoreanism and with ancient mystery cults, especially the Bacchic or Dionysiac mysteries. “Orphic poems,” i.e., poems attributed to Orpheus a mythic figure, circulated as early as the mid-sixth century B.C. We have only indirect evidence of the early Orphic poems; but we do have a sizable body of fragments from poems composed in later antiquity. Central to both early and later versions is a theogonic-cosmogonic narrative that posits Night as the primal entity  ostensibly a revision of the account offered by Hesiod  and gives major emphasis to organic unity Orphism 636    636 Ortega y Gasset, José outer converse 637 the birth, death through dismemberment, and rebirth of the god Dionysus. Plato gives us clear evidence of the existence in his time of itinerant religious teachers who, drawing on the “books of Orpheus,” performed and taught rituals of initiation and purification intended to procure divine favor either in this life or in an afterlife. The extreme skepticism of such scholars as Ulrich von Wilamowitz-Moellendorff and I. M. Linforth concerning the importance of early Orphism for Grecian religion and Grecian philosophy has been undermined by archaeological findings in recent decades: the Derveni papyrus, which is a fragment of a philosophical commentary on an Orphic theogony; and inscriptions with Orphic instructions for the dead, from funerary sites in southern Italy, mainland Greece, and the Crimea. A.P.D.M. Ortega y Gasset, José 18831955, Spanish philosopher and essayist. Born in Madrid, he studied there and in Leipzig, Berlin, and Marburg. In 1910 he was named professor of metaphysics at the  of Madrid and taught there until 1936, when he was forced to leave because of his political involvement in and support for the Spanish Republic. He returned to Spain in 1945. Ortega was a prolific writer whose works fill nine thick volumes. Among his most influential books are Meditaciones del Quijote “Meditations on the Quixote,” 1914, El tema de nuestro tiempo “The Modern Theme,” 1923, La revolución de las masas “The Revolt of the Masses,” 1932, La deshumanización del arte “The Dehumanization of Art,” 1925, Historia como sistema “History as a System,” 1941, and the posthumously published El hombre y la gente “Man and People,” 1957 and La idea de principio en Leibniz“The Idea of Principle in Leibniz,” 1958. His influence in Spain and Latin America was enormous, in part because of his brilliant style of writing and lecturing. He avoided jargon and rejected systematization; most of his works were first written as articles for newspapers and magazines. In 1923 he founded the Revista de Occidente, a cultural magazine that helped spread his ideas and introduced German thought into Spain and Latin America. Ortega ventured into nearly every branch of philosophy, but the kernel of his views is his metaphysics of vital reason rasón vital and his perspectival epistemology. For Ortega, reality is identified with “my life”; something is real only insofar as it is rooted and appears in “my life.” “My life” is further unpacked as “myself” and “my circumstances” “yo soy yo y mi circumstancia“. The self is not an entity separate from what surrounds it; there is a dynamic interaction and interdependence of self and things. These and the self together constitute reality. Because every life is the result of an interaction between self and circumstances, every self has a unique perspective. Truth, then, is perspectival, depending on the unique point of view from which it is determined, and no perspective is false except one that claims exclusivity. This doctrine is known as Ortega’s perspectivism.

ousia, ancient Grecian term traditionally translated as ‘substance’. Formed from the participle for ‘being’, the term ousia refers to the character of being, beingness, as if this were itself an entity. Just as redness is the character that red things have, so ousia is the character that beings have. Thus, the ousia of something is the character that makes it be, its nature. But ousia also refers to an entity that possesses being in its own right; for consider a case where the ousia of something is just the thing itself. Such a thing possesses being by virtue of itself; because its being depends on nothing else, it is self-subsistent and has a higher degree of being than things whose being depends on something else. Such a thing would be an ousia. Just which entities meet the criteria for ousia is a question addressed by Aristotle. Something such as redness that exists only as an attribute would not have being in its own right. An individual person is an ousia, but Aristotle also argues that his form is more properly an ousia; and an unmoved mover is the highest type of ousia. The traditional rendering of the term into Latin as substantia and English as ‘substance’ is appropriate only in contexts like Aristotle’s Categories where an ousia “stands under” attributes. In his Metaphysics, where Aristotle argues that being a substrate does not characterize ousia, and in other Grecian writers, ‘substance’ is often not an apt translation. 

Oxford Calculators, a group of natural philosophers, mathematicians, and logicians who flourished at Oxford  in the second quarter of the fourteenth century. The name derives from the Liber calculationum Book of Calculations, written some time before 1350. The author of this work, often called “Calculator” by later Continental authors, was probably named Richard Swineshead. The Book of Calculations discussed a number of issues related to the quantification or measurement of local motion, alteration, and augmentation for a fuller description, see John Murdoch and Edith Sylla, “Swineshead, Richard,” in Dictionary of Scientific Biography, Vol. 13, 1976. The Book of Calculations has been studied mainly by historians of science and grouped together with a number of other works discussing natural philosophical topics by such authors as Thomas Bradwardine, William Heytesbury, and John Dumbleton. In earlier histories many of the authors now referred to as Oxford Calculators are referred to as the Merton School, since many of them were fellows of Merton . But since some authors whose work appears to fit into the same intellectual tradition e.g., Richard Kilvington, whose Sophismata represents an earlier stage of the tradition later epitomized by William Heytesbury’s Sophismata have no known connection with Merton , the name ‘Oxford Calculators’ would appear to be a more accurate appellation. The works of the Oxford Calculators were produced in the context of education in the Oxford arts faculty see Edith Sylla, “The Oxford Calculators,” in Norman Kretzmann, Anthony Kenny, and Jan Pinborg, eds., The Cambridge History of Later Medieval Philosophy, 1982. In Oxford at this time logic was the centerpiece of the early years of undergraduate education. After logic, Oxford came to be known for its work in mathematics, astronomy, and natural philosophy. Students studying under the Oxford faculty of arts not only heard lectures on the liberal arts and on natural philosophy, moral philosophy, and metaphysics; they were also required to take part in disputations. William Heytesbury’s Regule solvendi sophismatum Rules for Solving Sophismata explicitly and Swineshead’s Book of Calculations implicitly are written to prepare students for these disputations. The three influences most formative on the work of the Oxford Calculators were 1 the tradition of commentaries on the works of Aristotle; 2 the developments in logical theory, particularly the theories of categorematic and syncategorematic terms and the theory of logical supposition; and 3 developments in mathematics, particularly the theory of ratios as developed in Thomas Bradwardine’s De proportionibus velocitatum in motibus On the Ratios of Velocities in Motions. In addition to Richard Swineshead, Heytesbury, Bradwardine, Dumbleton, and Kilvington, other authors and works related to the work of the Oxford Calculators are Walter Burley, De primo et ultimo instanti, Tractatus Primus De formis accidentalibus, Tractatus Secundus De intensione et remissione formarum; Roger Swineshead, Descriptiones motuum; and John Bode, A est unum calidum. These and other works had a considerable later influence on the Continent. 

pacifism, 1 opposition to war, usually on moral or religious grounds, but sometimes on the practical ground pragmatic pacifism that it is wasteful and ineffective; 2 opposition to all killing and violence; 3 opposition only to war of a specified kind e.g., nuclear pacifism. Not to be confused with passivism, pacifism usually involves actively promoting peace, understood to imply cooperation and justice among peoples and not merely absence of war. But some usually religious pacifists accept military service so long as they do not carry weapons. Many pacifists subscribe to nonviolence. But some consider violence and/or killing permissible, say, in personal self-defense, law enforcement, abortion, or euthanasia. Absolute pacifism rejects war in all circumstances, hypothetical and actual. Conditional pacifism concedes war’s permissibility in some hypothetical circumstances but maintains its wrongness in practice. If at least some hypothetical wars have better consequences than their alternative, absolute pacifism will almost inevitably be deontological in character, holding war intrinsically wrong or unexceptionably prohibited by moral principle or divine commandment. Conditional pacifism may be held on either deontological or utilitarian teleological or sometimes consequentialist grounds. If deontological, it may hold war at most prima facie wrong intrinsically but nonetheless virtually always impermissible in practice because of the absence of counterbalancing right-making features. If utilitarian, it will hold war wrong, not intrinsically, but solely because of its consequences. It may say either that every particular war has worse consequences than its avoidance act utilitarianism or that general acceptance of or following or compliance with a rule prohibiting war will have best consequences even if occasional particular wars have best consequences rule utilitarianism. 

Paine, Thomas 17371809, American political philosopher, revolutionary defender of democracy and human rights, and champion of popular radicalism in three countries. Born in Thetford, England, he emigrated to the American colonies in 1774; he later moved to France, where he was made a French citizen in 1792. In 1802 he returned to the United States, where he was rebuffed by the public because of his support for the French Revolution. Paine was the bestknown polemicist for the American Revolution. In many incendiary pamphlets, he called for a new, more democratic republicanism. His direct style and uncompromising egalitarianism had wide popular appeal. In Common Sense 1776 Paine asserted that commoners were the equal of the landed aristocracy, thus helping to spur colonial resentments sufficiently to support independence from Britain. The sole basis of political legitimacy is universal, active consent; taxation without representation is unjust; and people have the right to resist when the contract between governor and governed is broken. He defended the French Revolution in The Rights of Man 179192, arguing against concentrating power in any one individual and against a property qualification for suffrage. Since natural law and right reason as conformity to nature are accessible to all rational persons, sovereignty resides in human beings and is not bestowed by membership in class or nation. Opposed to the extremist Jacobins, he helped write, with Condorcet, a constitution to secure the Revolution. The Age of Reason 1794, Paine’s most misunderstood work, sought to secure the social cohesion necessary to a well-ordered society by grounding it in belief in a divinity. But in supporting deism and attacking established religion as a tool of enslavement, he alienated the very laboring classes he sought to enlighten. A lifelong adversary of slavery and supporter of universal male suffrage, Paine argued for redistributing property in Agrarian Justice 1797. 

Paley, William, 17431805, English moral philosopher and theologian. He was born in Peterborough and educated at Cambridge, 639 P    639 where he lectured in moral philosophy, divinity, and Grecian New Testament before assuming a series of posts in the Church of England, the last as archdeacon of Carlisle. The Principles of Moral and Political Philosophy 1785 first introduced utilitarianism to a wide public. Moral obligation is created by a divine command “coupled” with the expectation of everlasting rewards or punishments. While God’s commands can be ascertained “from Scripture and the light of nature,” Paley emphasizes the latter. Since God wills human welfare, the rightness or wrongness of actions is determined by their “tendency to promote or diminish the general happiness.” Horae Pauline: Or the Truth of the Scripture History of St Paul Evinced appeared in 1790, A View of the Evidences of Christianity in 1794. The latter defends the authenticity of the Christian miracles against Hume. Natural Theology 1802 provides a design argument for God’s existence and a demonstration of his attributes. Nature exhibits abundant contrivances whose “several parts are framed and put together for a purpose.” These contrivances establish the existence of a powerful, wise, benevolent designer. They cannot show that its power and wisdom are unlimited, however, and “omnipotence” and “omniscience” are mere “superlatives.” Paley’s Principles and Evidences served as textbooks in England and America well into the nineteenth century. 

panpsychism, the doctrine that the physical world is pervasively psychical, sentient or conscious understood as equivalent. The idea, usually, is that it is articulated into certain ultimate units or particles, momentary or enduring, each with its own distinct charge of sentience or consciousness, and that some more complex physical units possess a sentience emergent from the interaction between the charges of sentience pertaining to their parts, sometimes down through a series of levels of articulation into sentient units. Animal consciousness is the overall sentience pertaining to some substantial part or aspect of the brain, while each neuron may have its own individual charge of sentience, as may each included atom and subatomic particle. Elsewhere the only sentient units may be at the atomic and subatomic level. Two differently motivated versions of the doctrine should be distinguished. The first implies no particular view about the nature of matter, and regards the sentience pertaining to each unit as an extra to its physical nature. Its point is to explain animal and human consciousness as emerging from the interaction and perhaps fusion of more pervasive sentient units. The better motivated, second version holds that the inner essence of matter is unknown. We know only structural facts about the physical or facts about its effects on sentience like our own. Panpsychists hypothesize that the otherwise unknown inner essence of matter consists in sentience or consciousness articulated into the units we identify externally as fundamental particles, or as a supervening character pertaining to complexes of such or complexes of complexes, etc. Panpsychists can thus uniquely combine the idealist claim that there can be no reality without consciousness with rejection of any subjectivist reduction of the physical world to human experience of it. Modern versions of panpsychism e.g. of Whitehead, Hartshorne, and Sprigge are only partly akin to hylozoism as it occurred in ancient thought. Note that neither version need claim that every physical object possesses consciousness; no one supposes that a team of conscious cricketers must itself be conscious. 

pantheism, the view that God is identical with everything. It may be seen as the result of two tendencies: an intense religious spirit and the belief that all reality is in some way united. Pantheism should be distinguished from panentheism, the view that God is in all things. Just as water might saturate a sponge and in that way be in the entire sponge, but not be identical with the sponge, God might be in everything without being identical with everything. Spinoza is the most distinguished pantheist in Western philosophy. He argued that since substance is completely self-sufficient, and only God is self-sufficient, God is the only substance. In other words, God is everything. Hegel is also sometimes considered a pantheist since he identifies God with the totality of being. Many people think that pantheism is tantamount to atheism, because they believe that theism requires that God transcend ordinary, sensible reality at least to some degree. It is not obvious that theism requires a transcendent or Panaetius pantheism 640    640 personal notion of God; and one might claim that the belief that it does is the result of an anthropomorphic view of God. In Eastern philosophy, especially the Vedic tradition of Indian philosophy, pantheism is part of a rejection of polytheism. The apparent multiplicity of reality is illusion. What is ultimately real or divine is Brahman. 

Pantheismusstreit German, ‘dispute over pantheism’, a debate primarily between the German philosophers Jacobi and Mendelssohn, although it also included Lessing, Kant, and Goethe. The basic issue concerned what pantheism is and whether all pantheists are atheists. In particular, it concerned whether Spinoza was a pantheist, and if so, whether he was an atheist; and how close Lessing’s thought was to Spinoza’s. The standard view, propounded by Bayle and Leibniz, was that Spinoza’s pantheism was a thin veil for his atheism. Lessing and Goethe did not accept this harsh interpretation of him. They believed that his pantheism avoided the alienating transcendence of the standard Judeo-Christian concept of God. It was debated whether Lessing was a Spinozist or some form of theistic pantheist. Lessing was critical of dogmatic religions and denied that there was any revelation given to all people for rational acceptance. He may have told Jacobi that he was a Spinozist; but he may also have been speaking ironically or hypothetically. 

Paracelsus, pseudonym of Theophrastus Bombastus von Hohenheim 14931541, Swiss chemist, physician, and natural philosopher. He pursued medical studies at various German and Austrian universities, probably completing them at Ferrara 151316. Thereafter he had little to do with the academic world, apart from a brief and stormy period as professor of medicine at Basle 152728. Instead, he worked first as a military surgeon and later as an itinerant physician in Germany, Austria, and Switzerland. His works were mainly in German rather than Latin, and only a few were published during his lifetime. His importance for medical practice lay in his insistence on observation and experiment, and his use of chemical methods for preparing drugs. The success of Paracelsian medicine and chemistry in the later sixteenth and seventeenth centuries was, however, largely due to the theoretical background he provided. He firmly rejected the classical medical inheritance, particularly Galen’s explanation of disease as an imbalance of humors; he drew on a combination of biblical sources, German mysticism, alchemy, and Neoplatonic magic as found in Ficino to present a unified view of humankind and the universe. He saw man as a microcosm, reflecting the nature of the divine world through his immortal soul, the sidereal world through his astral body or vital principle, and the terrestrial world through his visible body. Knowledge requires union with the object, but because elements of all the worlds are found in man, he can acquire knowledge of the universe and of God, as partially revealed in nature. The physician needs knowledge of vital principles called astra in order to heal. Disease is caused by external agents that can affect the human vital principle as well as the visible body. Chemical methods are employed to isolate the appropriate vital principles in minerals and herbs, and these are used as antidotes. Paracelsus further held that matter contains three principles, sulfur, mercury, and salt. As a result, he thought it was possible to transform one metal into another by varying the proportions of the fundamental principles; and that such transformations could also be used in the production of drugs. 

paraconsistency, the property of a logic in which one cannot derive all statements from a contradiction. What is objectionable about contradictions, from the standpoint of classical logic, is not just that they are false but that they imply any statement whatsoever: one who accepts a contradiction is thereby committed to accepting everything. In paraconsistent logics, however, such as relevance logics, contradictions are isolated inferentially and thus rendered relatively harmless. The interest in such logics stems from the fact that people sometimes continue to work in inconsistent theories even after the inconsistency has been exposed, and do so without inferring everything. Whether this phenomenon can be explained satisfactorily by the classical logician or shows instead that the underlying logic of, e.g., science and mathematics is some non-classical paraconsistent logic, is disputed. 

paradigm, as used by Thomas Kuhn The Structure of Scientific Revolutions, 1962, a set of scientific and metaphysical beliefs that make up a theoretical framework within which scientific theories can be tested, evaluated, and if necessary revised. Kuhn’s principal thesis, in which the notion of a paradigm plays a central role, is structured around an argument against the logical empiricist view of scientific theory change. Empiricists viewed theory change as an ongoing smooth and cumulative process in which empirical facts, discovered through observation or experimentation, forced revisions in our theories and thus added to our ever-increasing knowledge of the world. It was claimed that, combined with this process of revision, there existed a process of intertheoretic reduction that enabled us to understand the macro in terms of the micro, and that ultimately aimed at a unity of science. Kuhn maintains that this view is incompatible with what actually happens in case after case in the history of science. Scientific change occurs by “revolutions” in which an older paradigm is overthrown and is replaced by a framework incompatible or even incommensurate with it. Thus the alleged empirical “facts,” which were adduced to support the older theory, become irrelevant to the new; the questions asked and answered in the new framework cut across those of the old; indeed the vocabularies of the two frameworks make up different languages, not easily intertranslatable. These episodes of revolution are separated by long periods of “normal science,” during which the theories of a given paradigm are honed, refined, and elaborated. These periods are sometimes referred to as periods of “puzzle solving,” because the changes are to be understood more as fiddling with the details of the theories to “save the phenomena” than as steps taking us closer to the truth. A number of philosophers have complained that Kuhn’s conception of a paradigm is too imprecise to do the work he intended for it. In fact, Kuhn, fifteen years later, admitted that at least two distinct ideas were exploited by the term: i the “shared elements [that] account for the relatively unproblematic character of professional communication and for the relative unanimity of professional judgment,” and ii “concrete problem solutions, accepted by the group [of scientists] as, in a quite usual sense, paradigmatic” Kuhn, “Second Thoughts on Paradigms,” 1977. Kuhn offers the terms ‘disciplinary matrix’ and ‘exemplar’, respectively, for these two ideas. 

paradigm case argument, an argument designed to yield an affirmative answer to the following general type of skeptically motivated question: Are A’s really B? E.g., Do material objects really exist? Are any of our actions really free? Does induction really provide reasonable grounds for one’s beliefs? The structure of the argument is simple: in situations that are “typical,” “exemplary,” or “paradigmatic,” standards for which are supplied by common sense, or ordinary language, part of what it is to be B essentially involves A. Hence it is absurd to doubt if A’s are ever B, or to doubt if in general A’s are B. More commonly, the argument is encountered in the linguistic mode: part of what it means for something to be B is that, in paradigm cases, it be an A. Hence the question whether A’s are ever B is meaningless. An example may be found in the application of the argument to the problem of induction. See Strawson, Introduction to Logical Theory, 1952. When one believes a generalization of the form ‘All F’s are G’ on the basis of good inductive evidence, i.e., evidence constituted by innumerable and varied instances of F all of which are G, one would thereby have good reasons for holding this belief. The argument for this claim is based on the content of the concepts of reasonableness and of strength of evidence. Thus according to Strawson, the following two propositions are analytic: 1 It is reasonable to have a degree of belief in a proposition that is proportional to the strength of the evidence in its favor. 2 The evidence for a generalization is strong in proportion as the number of instances, and the variety of circumstances in which they have been found, is great. Hence, Strawson concludes, “to ask whether it is reasonable to place reliance on inductive procedures is like asking whether it is reasonable to proportion the degree of one’s convictions to the strength of the evidence. Doing this is what ‘being reasonable’ means in such a context” p. 257. In such arguments the role played by the appeal to paradigm cases is crucial. In Strawson’s version, paradigm cases are constituted by “innumerable and varied instances.” Without such an appeal the argument would fail completely, for it is clear that not all uses of induction are reasonable. Even when this appeal is made clear though, the argument remains questionable, for it fails to confront adequately the force of the word ‘really’ in the skeptical challenges. paradigm case argument paradigm case argument

paradox, a seemingly sound piece of reasoning based on seemingly true assumptions that leads to a contradiction or other obviously false conclusion. A paradox reveals that either the principles of reasoning or the assumptions on which it is based are faulty. It is said to be solved when the mistaken principles or assumptions are clearly identified and rejected. The philosophical interest in paradoxes arises from the fact that they sometimes reveal fundamentally mistaken assumptions or erroneous reasoning techniques. Two groups of paradoxes have received a great deal of attention in modern philosophy. Known as the semantic paradoxes and the logical or settheoretic paradoxes, they reveal serious difficulties in our intuitive understanding of the basic notions of semantics and set theory. Other well-known paradoxes include the barber paradox and the prediction or hangman or unexpected examination paradox. The barber paradox is mainly useful as an example of a paradox that is easily resolved. Suppose we are told that there is an Oxford barber who shaves all and only the Oxford men who do not shave themselves. Using this description, we can apparently derive the contradiction that this barber both shaves and does not shave himself. If he does not shave himself, then according to the description he must be one of the people he shaves; if he does shave himself, then according to the description he is one of the people he does not shave. This paradox can be resolved in two ways. First, the original claim that such a barber exists can simply be rejected: perhaps no one satisfies the alleged description. Second, the described barber may exist, but not fall into the class of Oxford men: a woman barber, e.g., could shave all and only the Oxford men who do not shave themselves. The prediction paradox takes a variety of forms. Suppose a teacher tells her students on Friday that the following week she will give a single quiz. But it will be a surprise: the students will not know the evening before that the quiz will take place the following day. They reason that she cannot give such a quiz. After all, she cannot wait until Friday to give it, since then they would know Thursday evening. That leaves Monday through Thursday as the only possible days for it. But then Thursday can be ruled out for the same reason: they would know on Wednesday evening. Wednesday, Tuesday, and Monday can be ruled out by similar reasoning. Convinced by this seemingly correct reasoning, the students do not study for the quiz. On Wednesday morning, they are taken by surprise when the teacher distributes it. It has been pointed out that the students’ reasoning has this peculiar feature: in order to rule out any of the days, they must assume that the quiz will be given and that it will be a surprise. But their alleged conclusion is that it cannot be given or else will not be a surprise, undermining that very assumption. Kaplan and Montague have argued in “A Paradox Regained,” Notre Dame Journal of Formal Logic, 1960 that at the core of this puzzle is what they call the knower paradox  a paradox that arises when intuitively plausible principles about knowledge and its relation to logical consequence are used in conjunction with knowledge claims whose content is, or entails, a denial of those very claims. 

paradoxes of omnipotence, a series of paradoxes in philosophical theology that maintain that God could not be omnipotent because the concept is inconsistent, alleged to result from the intuitive idea that if God is omnipotent, then God must be able to do anything. 1 Can God perform logically contradictory tasks? If God can, then God should be able to make himself simultaneously omnipotent and not omnipotent, which is absurd. If God cannot, then it appears that there is something God cannot do. Many philosophers have sought to avoid this consequence by claiming that the notion of performing a logically contradictory task is empty, and that question 1 specifies no task that God can perform or fail to perform. 2 Can God cease to be omnipotent? If God can and were to do so, then at any time thereparadox paradoxes of omnipotence 643    643 after, God would no longer be completely sovereign over all things. If God cannot, then God cannot do something that others can do, namely, impose limitations on one’s own powers. A popular response to question 2 is to say that omnipotence is an essential attribute of a necessarily existing being. According to this response, although God cannot cease to be omnipotent any more than God can cease to exist, these features are not liabilities but rather the lack of liabilities in God. 3 Can God create another being who is omnipotent? Is it logically possible for two beings to be omnipotent? It might seem that there could be, if they never disagreed in fact with each other. If, however, omnipotence requires control over all possible but counterfactual situations, there could be two omnipotent beings only if it were impossible for them to disagree. 4 Can God create a stone too heavy for God to move? If God can, then there is something that God cannot do  move such a stone  and if God cannot, then there is something God cannot do  create such a stone. One reply is to maintain that ‘God cannot create a stone too heavy for God to move’ is a harmless consequence of ‘God can create stones of any weight and God can move stones of any weight.’ 

paradox of analysis, an argument that it is impossible for an analysis of a meaning to be informative for one who already understands the meaning. Consider: ‘An F is a G’ e.g., ‘A circle is a line all points on which are equidistant from some one point’ gives a correct analysis of the meaning of ‘F’ only if ‘G’ means the same as ‘F’; but then anyone who already understands both meanings must already know what the sentence says. Indeed, that will be the same as what the trivial ‘An F is an F’ says, since replacing one expression by another with the same meaning should preserve what the sentence says. The conclusion that ‘An F is a G’ cannot be informative for one who already understands all its terms is paradoxical only for cases where ‘G’ is not only synonymous with but more complex than ‘F’, in such a way as to give an analysis of ‘F’. ‘A first cousin is an offspring of a parent’s sibling’ gives an analysis, but ‘A dad is a father’ does not and in fact could not be informative for one who already knows the meaning of all its words. The paradox appears to fail to distinguish between different sorts of knowledge. Encountering for the first time and understanding a correct analysis of a meaning one already grasps brings one from merely tacit to explicit knowledge of its truth. One sees that it does capture the meaning and thereby sees a way of articulating the meaning one had not thought of before. 

paradox of omniscience, an objection to the possibility of omniscience, developed by Patrick Grim, that appeals to an application of Cantor’s power set theorem. Omniscience requires knowing all truths; according to Grim, that means knowing every truth in the set of all truths. But there is no set of all truths. Suppose that there were a set T of all truths. Consider all the subsets of T, that is, all members of the power set 3T. Take some truth T1. For each member of 3T either T1 is a member of that set or T1 is not a member of that set. There will thus correspond to each member of 3T a further truth specifying whether T1 is or is not a member of that set. Therefore there are at least as many truths as there are members of 3T. By the power set theorem, there are more members of 3T than there are of T. So T is not the set of all truths. By a parallel argument, no other set is, either. So there is no set of all truths, after all, and therefore no one who knows every member of that set. The objection may be countered by denying that the claim ‘for every proposition p, if p is true God knows that p’ requires that there be a set of all true propositions. 

parapsychology, the study of certain anomalous phenomena and ostensible causal connections neither recognized nor clearly rejected by traditional science. Parapsychology’s principal areas of investigation are extrasensory perception ESP, psychokinesis PK, and cases suggesting the survival of mental functioning following bodily death. The study of ESP has traditionally focused on two sorts of ostensible phenomena, telepathy the apparent anomalous influence of one person’s mental states on those of another, commonly identified with apparent communication between two minds by extrasensory means and clairvoyance the apparent anomalous influence of a physical state of affairs on a person’s mental states, commonly identified with the supposed ability to perceive or know of objects or events not present to the senses. The forms of ESP may be viewed either as types of cognition e.g., the anomalous knowledge of another person’s mental states or as merely a form of anomalous causal influence e.g., a distant burning house causing one to have  possibly incongruous  thoughts about fire. The study of PK covers the apparent ability to produce various physical effects independently of familiar or recognized intermediate sorts of causal links. These effects include the ostensible movement of remote objects, materializations the apparently instantaneous production of matter, apports the apparently instantaneous relocation of an object, and in laboratory experiments statistically significant non-random behavior of normally random microscopic processes such as radioactive decay. Survival research focuses on cases of ostensible reincarnation and mental mediumship i.e., “channeling” of information from an apparently deceased communicator. Cases of ostensible precognition may be viewed as types of telepathy and clairvoyance, and suggest the causal influence of some state of affairs on an earlier event an agent’s ostensible precognitive experience. However, those opposed to backward causation may interpret ostensible precognition either as a form of unconscious inference based on contemporaneous information acquired by ESP, or else as a form of PK possibly in conjunction with telepathic influence by which the precognizer brings about the events apparently precognized. The data of parapsychology raise two particularly deep issues. The evidence suggesting survival poses a direct challenge to materialist theories of the mental. And the evidence for ESP and PK suggests the viability of a “magical” worldview associated usually with so-called primitive societies, according to which we have direct and intimate access to and influence on the thoughts and bodily states of others. 

Pareto efficiency, also called Pareto optimality, a state of affairs in which no one can be made better off without making someone worse off. The Italian economist Vilfredo Pareto 18481923 referred to optimality rather than efficiency, but usage has drifted toward the less normative term. Pareto supposed that utilitarian addition of welfare across individuals is meaningless. He concluded that the only useful aggregate measures of welfare must be ordinal. One state of affairs is Pareto-superior to another if we cannot move to the second state without making someone worse off. Although the Pareto criteria are generally thought to be positive rather than normative, they are often used as normative principles for justifying particular changes or refusals to make changes. For example, some economists and philosophers take the Pareto criteria as moral constraints and therefore oppose certain government policies. In market and voluntary exchange contexts, it makes sense to suppose every exchange will be Pareto-improving, at least for the direct parties to the exchange. If, however, we fail to account for external effects of our exchange on other people, it may not be Pareto-improving. Moreover, we may fail to provide collective benefits that require the cooperation or coordination of many individuals’ efforts. Hence, even in markets, we cannot expect to achieve Pareto efficiency. We might therefore suppose we should invite government intervention to help us. But in typical social contexts, it is often hard to believe that significant policy changes can be Paretoimproving: there are sure to be losers from any change. 

Parfit, Derek b.1942, British philosopher internationally known for his major contributions to the metaphysics of persons, moral theory, and practical reasoning. Parfit first rose to prominence by challenging the prevalent view that personal identity is a “deep fact” that must be all or nothing and that matters greatly in rational and moral deliberations. Exploring puzzle cases involving fission and fusion, Parfit propounded a reductionist account of personal identity, arguing that what matters in survival are physical and psychological continuities. These are a matter of degree, and sometimes there may be no answer as to whether some future person would be me. Parfit’s magnum opus, Reasons and Persons 1984, is a strikingly original book brimming with startling conclusions that have significantly reshaped the philosophical agenda. Part One treats different theories of morality, rationality, and the good; blameless wrongdoing; moral immorality; rational irrationality; imperceptible harms and benefits; harmless torturers; and the self-defeatingness of certain theories. Part Two introduces a critical present-aim theory of individual rationality, and attacks the standard selfinterest theory. It also discusses the rationality of different attitudes to time, such as caring more about the future than the past, and more about the near than the remote. Addressing the age-old conflict between self-interest and morality, Parfit illustrates that contrary to what the self-interest theory demands, it can be rational to care about certain other aims as much as, or more than, about our own future well-being. In addition, Parfit notes that the self-interest theory is a hybrid position, neutral with respect to time but partial with respect to persons. Thus, it can be challenged from one direction by morality, which is neutral with respect to both persons and time, and from the other by a present-aim theory, which is partial with respect to both persons and time. Part Three refines Parfit’s views regarding personal identity and further criticizes the self-interest theory: personal identity is not what matters, hence reasons to be specially concerned about our future are not provided by the fact that it will be our future. Part Four presents puzzles regarding future generations and argues that the moral principles we need when considering future people must take an impersonal form. Parfit’s arguments deeply challenge our understanding of moral ideals and, some believe, the possibility of comparing outcomes. Parfit has three forthcoming manuscripts, tentatively titled Rediscovering Reasons, The Metaphysics of the Self, and On What Matters. His current focus is the normativity of reasons. A reductionist about persons, he is a non-reductionist about reasons. He believes in irreducibily normative beliefs that are in a strong sense true. A realist about reasons for acting and caring, he challenges the views of naturalists, noncognitivists, and constructivists. Parfit contends that internalists conflate normativity with motivating force, that contrary to the prevalent view that all reasons are provided by desires, no reasons are, and that Kant poses a greater threat to rationalism than Hume. Parfit is Senior Research Fellow of All Souls , Oxford, and a regular visiting professor at both Harvard and New York . Legendary for monograph-length criticisms of book manuscripts, he is editor of the Oxford Ethics Series, whose goal is to make definite moral progress, a goal Parfit himself is widely believed to have attained. 

Parmenides early fifth century B.C., Grecian philosopher, the most influential of the preSocratics, active in Elea Roman and modern Velia, an Ionian Grecian colony in southern Italy. He was the first Grecian thinker who can properly be called an ontologist or metaphysician. Plato refers to him as “venerable and awesome,” as “having magnificent depth” Theaetetus 183e 184a, and presents him in the dialogue Parmenides as a searching critic  in a fictional and dialectical transposition  of Plato’s own theory of Forms. Nearly 150 lines of a didactic poem by Parmenides have been preserved, assembled into about twenty fragments. The first part, “Truth,” provides the earliest specimen in Grecian intellectual history of a sustained deductive argument. Drawing on intuitions concerning thinking, knowing, and language, Parmenides argues that “the real” or “what-is” or “being” to eon must be ungenerable and imperishable, indivisible, and unchanging. According to a Plato-inspired tradition, Parmenides held that “all is one.” But the phrase does not occur in the fragments; Parmenides does not even speak of “the One”; and it is possible that either a holistic One or a plurality of absolute monads might conform to Parmenides’ deduction. Nonetheless, it is difficult to resist the impression that the argument converges on a unique entity, which may indifferParfit, Derek Parmenides 646    646 ently be referred to as Being, or the All, or the One. Parmenides embraces fully the paradoxical consequence that the world of ordinary experience fails to qualify as “what-is.” Nonetheless, in “Opinions,” the second part of the poem, he expounds a dualist cosmology. It is unclear whether this is intended as candid phenomenology  a doctrine of appearances  or as an ironic foil to “Truth.” It is noteworthy that Parmenides was probably a physician by profession. Ancient reports to this effect are borne out by fragments from “Opinions” with embryological themes, as well as by archaeological findings at Velia that link the memory of Parmenides with Romanperiod remains of a medical school at that site. Parmenides’ own attitude notwithstanding, “Opinions” recorded four major scientific breakthroughs, some of which, doubtless, were Parmenides’ own discoveries: that the earth is a sphere; that the two tropics and the Arctic and Antarctic circles divide the earth into five zones; that the moon gets its light from the sun; and that the morning star and the evening star are the same planet. The term Eleatic School is misleading when it is used to suggest a common doctrine supposedly held by Parmenides, Zeno of Elea, Melissus of Samos, and anticipating Parmenides Xenophanes of Colophon. The fact is, many philosophical groups and movements, from the middle of the fifth century onward, were influenced, in different ways, by Parmenides, including the “pluralists,” Empedocles, Anaxagoras, and Democritus. Parmenides’ deductions, transformed by Zeno into a repertoire of full-blown paradoxes, provided the model both for the eristic of the Sophists and for Socrates’ elenchus. Moreover, the Parmenidean criteria for “whatis” lie unmistakably in the background not only of Plato’s theory of Forms but also of salient features of Aristotle’s system, notably, the priority of actuality over potentiality, the unmoved mover, and the man-begets-man principle. Indeed, all philosophical and scientific systems that posit principles of conservation of substance, of matter, of matter-energy are inalienably the heirs to Parmenides’ deduction.

parsing, the process of determining the syntactic structure of a sentence according to the rules of a given grammar. This is to be distinguished from the generally simpler task of recognition, which is merely the determination of whether or not a given string is well-formed grammatical. In general, many different parsing strategies can be employed for grammars of a particular type, and a great deal of attention has been given to the relative efficiencies of these techniques. The most thoroughly studied cases center on the contextfree phrase structure grammars, which assign syntactic structures in the form of singly-rooted trees with a left-to-right ordering of “sister” nodes. Parsing procedures can then be broadly classified according to the sequence of steps by which the parse tree is constructed: top-down versus bottom-up; depth-first versus breadthfirst; etc. In addition, there are various strategies for exploring alternatives agendas, backtracking, parallel processing and there are devices such as “charts” that eliminate needless repetitions of previous steps. Efficient parsing is of course important when language, whether natural or artificial e.g., a programming language, is being processed by computer. Human beings also parse rapidly and with apparently little effort when they comprehend sentences of a natural language. Although little is known about the details of this process, psycholinguists hope that study of mechanical parsing techniques might provide insights.

partition, division of a set into mutually exclusive and jointly exhaustive subsets. Derivatively, parousia partition 647    647 ‘partition’ can mean any set P whose members are mutually exclusive and jointly exhaustive subsets of set S. Each subset of a partition P is called a partition class of S with respect to P. Partitions are intimately associated with equivalence relations, i.e. with relations that are transitive, symmetric, and reflexive. Given an equivalence relation R defined on a set S, R induces a partition P of S in the following natural way: members s1 and s2 belong to the same partition class of P if and only if s1 has the relation R to s2. Conversely, given a partition P of a set S, P induces an equivalence relation R defined on S in the following natural way: members s1 and s2 are such that s1 has the relation R to s2 if and only if s1 and s2 belong to the same partition class of P. For obvious reasons, then, partition classes are also known as equivalence classes. 

Pascal, Blaise 162362, French philosopher known for his brilliance as a mathematician, physicist, inventor, theologian, polemicist, and French prose stylist. Born at Clermont-Ferrand in the Auvergne, he was educated by his father, Étienne, and first gained note for his contribution to mathematics when at sixteen he produced, under the influence of Desargues, a work on the projective geometry of the cone. This was published in 1640 under the title Essai pour les coniques and includes what has since become known as Pascal’s theorem. Pascal’s other mathematical accomplishments include the original development of probability theory, worked out in correspondence with Fermat, and a method of infinitesimal analysis to which Leibniz gave credit for inspiring his own development of the calculus. Pascal’s early scientific fame rests also on his work in physics, which includes a treatise on hydrostatics Traités de l’équilibre des liqueurs et de la pesanteur de la masse de l’air and his experiments with the barometer, which attempted to establish the possibility of a vacuum and the weight of air as the cause of the mercury’s suspension. Pascal’s fame as a stylist rests primarily on his Lettres provinciales 165657, which were an anonymous contribution to a dispute between the Jansenists, headed by Arnauld, and the Jesuits. Jansenism was a Catholic religious movement that emphasized an Augustinian position on questions of grace and free will. Pascal, who was not himself a Jansenist, wrote a series of scathing satirical letters ridiculing both Jesuit casuistry and the persecution of the Jansenists for their purported adherence to five propositions in Jansen’s Augustinus. Pascal’s philosophical contributions are found throughout his work, but primarily in his Pensées 1670, an intended apology for Christianity left incomplete and fragmentary at his death. The influence of the Pensées on religious thought and later existentialism has been profound because of their extraordinary insight, passion, and depth. At the time of Pascal’s death some of the fragments were sewn together in clusters; many others were left unorganized, but recent scholarship has recovered much of the original plan of organization. The Pensées raise skeptical arguments that had become part of philosophical parlance since Montaigne. While these arguments were originally raised in order to deny the possibility of knowledge, Pascal, like Descartes in the Meditations, tries to utilize them toward a positive end. He argues that what skepticism shows us is not that knowledge is impossible, but that there is a certain paradox about human nature: we possess knowledge yet recognize that this knowledge cannot be rationally justified and that rational arguments can even be directed against it fragments 109, 131, and 110. This peculiarity can be explained only through the Christian doctrine of the fall e.g., fragment 117. Pascal extends his skeptical considerations by undermining the possibility of demonstrative proof of God’s existence. Such knowledge is impossible on philosophical grounds because such a proof could be successful only if an absurdity followed from denying God’s existence, and nature furnishes us with no knowledge incompatible with unbelief fragments 429 and 781. Furthermore, demonstrative proof of God’s existence is incompatible with the epistemological claims of Christianity, which make God’s personal agency essential to religious knowledge fragments 460, 449. Pascal’s use of skepticism and his refusal to admit proofs of God’s existence have led some commentators, like Richard Popkin “Fideism,” 1967 and Terence Penelhum “Skepticism and Fideism,” 1983 to interpret Pascal as a fideist, i.e., one who denies that religious belief can be based on anything other than pragmatic reasons. But such an interpretation disregards Pascal’s attempts to show that Christian belief is rational because of the explanatory power of its doctrines, particularly its doctrine of the fall e.g., fragments 131, 137, 149, 431, 449, and 482. These purported demonstrations of the explanatory superiority of Christianity prepare Parva naturalia Pascal, Blaise 648    648 the way for Pascal’s famous “wager” fragment 418. The wager is among the fragments that Pascal had not classified at the time of his death, but textual evidence shows that it would have been included in Section 12, entitled “Commencement,” after the demonstrations of the superior explanatory power of Christianity. The wager is a direct application of the principles developed in Pascal’s earlier work on probability, where he discovered a calculus that could be used to determine the most rational action when faced with uncertainty about future events, or what is now known as decision theory. In this case the uncertainty is the truth of Christianity and its claims about afterlife; and the actions under consideration are whether to believe or not. The choice of the most rational action depends on what would now be called its “expected value.” The expected value of an action is determined by 1 assigning a value, s, to each possible outcome of the action, 2 subtracting the cost of the action, c, from this value, and 3 multiplying the difference by the probability of the respective outcomes and adding these products together. Pascal invites the reader to consider Christian faith and unbelief as if they were acts of wagering on the truth of Christianity. If one believes, then there are two possible outcomes  either God exists or not. If God does exist, the stake to be gained is infinite life. If God does not exist, there are no winnings. Because the potential winnings are infinite, religious belief is more rational than unbelief because of its greater expected value. The wager has been subjected to numerous criticisms. William James argued that it is indecisive, because it would apply with equal validity to any religion that offers a promise of infinite rewards The Will to Believe, 1897. But this ignores Pascal’s careful attempt to show that only Christianity has adequate explanatory power, so that the choice is intended to be between Christianity and unbelief. A stronger objection to the wager arises from contemporary work in decision theory that prohibits the introduction of infinite values because they have the counterintuitive result of making even the slightest risk irrational. But while these objections are valid, they do not refute Pascal’s strategy in the Pensées, in which the proofs of Christianity’s explanatory power and the wager have only the preliminary role of inducing the reader to seek the religious certainty that comes only from a saving religious experience which he calls “inspiration” fragments 110, 381, 382, 588, 808. 

paternalism, interference with the liberty or autonomy of another person, with justifications referring to the promotion of the person’s good or the prevention of harm to the person. More precisely, P acts paternalistically toward Q if and only if a P acts with the intent of averting some harm or promoting some benefit for Q; b P acts contrary to or is indifferent to the current preferences, desires or values of Q; and c P’s act is a limitation on Q’s autonomy or liberty. The presence of both autonomy and liberty in clause c is to allow for the fact that lying to someone is not clearly an interference with liberty. Notice that one can act paternalistically by telling people the truth as when a doctor insists that a patient know the exact nature of her illness, contrary to her wishes. Note also that the definition does not settle any questions about the legitimacy or illegitimacy of paternalistic interventions. Typical examples of paternalistic actions are 1 laws requiring motorcyclists to wear helmets; 2 court orders allowing physicians to transfuse Jehovah’s Witnesses against their wishes; 3 deception of a patient by physicians to avoid upsetting the patient; 4 civil commitment of persons judged dangerous to themselves; and 5 laws forbidding swimming while lifeguards are not on duty. Soft weak paternalism is the view that paternalism is justified only when a person is acting non-voluntarily or one needs time to determine whether the person is acting voluntarily or not. Hard strong paternalism is the view that paternalism is sometimes justified even when the person being interfered with is acting voluntarily. The analysis of the term is relative to some set of problems. If one were interested in the orgaPascal’s wager paternalism 649    649 nizational behavior of large corporations, one might adopt a different definition than if one were concerned with limits on the state’s right to exercise coercion. The typical normative problems about paternalistic actions are whether, and to what extent, the welfare of individuals may outweigh the need to respect their desire to lead their own lives and make their own decisions even when mistaken. J. S. Mill is the best example of a virtually absolute antipaternalism, at least with respect to the right of the state to act paternalistically. He argued that unless we have reason to believe that a person is not acting voluntarily, as in the case of a man walking across a bridge that, unknown to him, is about to collapse, we ought to allow adults the freedom to act even if their acts are harmful to themselves. 

patristic authors, also called church fathers, a group of early Christian authors originally so named because they were considered the “fathers” patres of the orthodox Christian churches. The term is now used more broadly to designate the Christian writers, orthodox or heterodox, who were active in the first six centuries or so of the Christian era. The chronological division is quite flexible, and it is regularly moved several centuries later for particular purposes. Moreover, the study of these writers has traditionally been divided by languages, of which the principal ones are Grecian, Latin, and Syriac. The often sharp divisions among patristic scholarships in the different languages are partly a reflection of the different histories of the regional churches, partly a reflection of the sociology of modern scholarship. Grecians. The patristic period in Grecian is usually taken as extending from the first writers after the New Testament to such figures as Maximus the Confessor 579/580662 or John of Damascus c.650c.750. The period is traditionally divided around the Council of Nicea 325. PreNicean Grecian authors of importance to the history of philosophy include Irenaeus 130/140 after 198?, Clement of Alexandria c.150after 215, and Origen c.180c.254. Important Nicean and post-Nicean authors include Athanasius c.295373; the Cappadocians, i.e., Gregory of Nazianzus c.33090, Basil of Cesarea c.33079, and his brother, Gregory of Nyssa 335/340c.394; and John Chrysostom c.350 407. Philosophical topics and practices are constantly engaged by these Grecian authors. Justin Martyr second century, e.g., describes his conversion to Christianity quite explicitly as a transit through lower forms of philosophy into the true philosophy. Clement of Alexandria, again, uses the philosophic genre of the protreptic and a host of ancient texts to persuade his pagan readers that they ought to come to Christianity as to the true wisdom. Origen devotes his Against Celsus to the detailed rebuttal of one pagan philosopher’s attack on Christianity. More importantly, if more subtly, the major works of the Cappadocians appropriate and transform the teachings of any number of philosophic authors  Plato and the Neoplatonists in first place, but also Aristotle, the Stoics, and Galen. Latins. The Latin churches came to count four post-Nicean authors as its chief teachers: Ambrose 337/33997, Jerome c.347419, Augustine 354430, and Gregory the Great c.540604. Other Latin authors of philosophical interest include Tertullian fl. c.195c.220, Lactantius c.260c.330, Marius Victorinus 280/285before 386, and Hilary of Poitiers fl. 35664. The Latin patristic period is typically counted from the second century to the fifth or sixth, i.e., roughly from Tertullian to Boethius. The Latin authors share with their Grecian contemporaries a range of relations to the pagan philosophic schools, both as rival institutions and as sources of useful teaching. Tertullian’s Against the Nations and Apology, for example, take up pagan accusations against Christianity and then counterattack a number of pagan beliefs, including philosophical ones. By contrast, the writings of Marius Victorinus, Ambrose, and Augustine enact transformations of philosophic teachings, especially from the Neoplatonists. Because philosophical erudition was generally not as great among the Latins as among the Grecians, they were both more eager to accept philosophical doctrines and freer in improvising variations on them. 

Paul of Venice c.13681429, Italian philosopher and theologian. A Hermit of Saint Augustine O.E.S.A., he spent three years as a student patriarchalism Paul of Venice 650    650 in Oxford 139093 and taught at the  of Padua, where he became a doctor of arts and theology in 1408. He also held appointments at the universities of Parma, Siena, and Bologna. He was active in the administration of his order, holding various high offices. Paul of Venice wrote commentaries on several logical, ethical, and physical works of Aristotle, but his name is connected especially with an extremely popular textbook, Logica parva over 150 manuscripts survive, and more than forty printed editions of it were made, and with a huge Logica magna. These Oxford-influenced works contributed to the favorable climate enjoyed by the English logic in northern Italian universities from the late fourteenth century through the fifteenth century. I.Bo. Peano, Giuseppe.

Peano postulates, also called Peano axioms, a list of assumptions from which the integers can be defined from some initial integer, equality, and successorship, and usually seen as defining progressions. The Peano postulates for arithmetic were produced by G. Peano in 1889. He took the set N of integers with a first term 1 and an equality relation between them, and assumed these nine axioms: 1 belongs to N; N has more than one member; equality is reflexive, symmetric, and associative, and closed over N; the successor of any integer in N also belongs to N, and is unique; and a principle of mathematical induction applying across the members of N, in that if 1 belongs to some subset M of N and so does the successor of any of its members, then in fact M % N. In some ways Peano’s formulation was not clear. He had no explicit rules of inference, nor any guarantee of the legitimacy of inductive definitions which Dedekind established shortly before him. Further, the four properties attached to equality were seen to belong to the underlying “logic” rather than to arithmetic itself; they are now detached. It was realized by Peano himself that the postulates specified progressions rather than integers e.g., 1, ½, ¼, 1 /8, . . . , would satisfy them, with suitable interpretations of the properties. But his work was significant in the axiomatization of arithmetic; still deeper foundations would lead with Russell and others to a major role for general set theory in the foundations of mathematics. In addition, with O. Veblen, T. Skolem, and others, this insight led in the early twentieth century to “non-standard” models of the postulates being developed in set theory and mathematical analysis; one could go beyond the ‘. . .’ in the sequence above and admit “further” objects, to produce valuable alternative models of the postulates. These procedures were of great significance also to model theory, in highlighting the property of the non-categoricity of an axiom system. A notable case was the “non-standard analysis” of A. Robinson, where infinitesimals were defined as arithmetical inverses of transfinite numbers without incurring the usual perils of rigor associated with them. 

peirce: c. s. – H. P. Grice, “Lectures on C. S. Peirce’s general theory of signs,” Oxford; philosopher, the founder of the philosophical movement called pragmatism. Peirce was born in Cambridge, Massachusetts, the second son of Benjamin Peirce, who was professor of mathematics and astronomy at Harvard and one of America’s leading mathematicians. Charles Peirce studied at Harvard  and in 1863 received a degree in chemistry. In 1861 he began work with the U.S. Coast and Geodetic Survey, and remained in this service for thirty years. Simultaneously with his professional career as a scientist, Peirce worked in logic and philosophy. He lectured on philosophy and logic at various universities and institutes, but was never able to obtain a permanent academic position as a teacher of philosophy. In 1887 he retired to Milford, Pennsylvania, and devoted the rest of his life to philosophical work. He earned a meager income from occasional lectures and by writing articles for periodicals and dictionaries. He spent his last years in extreme poverty and ill health. Pragmatism. Peirce formulated the basic principles of pragmatism in two articles, “The Fixation of Belief” and “How to Make Our Ideas Clear” 187778. The title of the latter paper refers to Descartes’s doctrine of clear and distinct ideas. According to Peirce, the criteria of clarity and distinctness must be supplemented by a third condition of meaningfulness, which states that the meaning of a proposition or an “intellectual conception” lies in its “practical consequences.” In his paper “Pragmatism” 1905 he formulated the “Principle of Pragmatism” or the “Pragmatic Maxim” as follows: In order to ascertain the meaning of an intellectual conception we should consider what practical consequences might conceivably result by necessity from the truth of that conception; and the sum of these consequences will constitute the entire meaning of the conception. By “practical consequences” Peirce means conditional propositions of the form ‘if p, then q’, where the antecedent describes some action or experimental condition, and the consequent describes an observable phenomenon or a “sensible effect.” According to the Pragmatic Maxim, the meaning of a proposition or of an “intellectual conception” can be expressed as a conjunction of such “practical conditionals.” The Pragmatic Maxim might be criticized on the ground that many meaningful sentences e.g., theoretical hypotheses do not entail any “practical consequences” in themselves, but only in conjunction with other hypotheses. Peirce anticipated this objection by observing that “the maxim of pragmatism is that a conception can have no logical effect or import differing from that of a second conception except so far as, taken in connection with other conceptions and intentions, it might conceivably modify our practical conduct differently from that of the second conception” “Pragmatism and Abduction,” 1903. Theory of inquiry and philosophy of science. Peirce adopted Bain’s definition of belief as “that which a man is prepared to act upon.” Belief guides action, and as a content of belief a proposition can be regarded as a maxim of conduct. According to Peirce, belief is a satisfactory and desirable state, whereas the opposite of belief, the state of doubt, is an unsatisfactory state. The starting point of inquiry is usually some surprising phenomenon that is inconsistent with one’s previously accepted beliefs, and that therefore creates a state of doubt. The purpose of inquiry is the replacement of this state by that of belief: “the sole aim of inquiry is the settlement of opinion.” A successful inquiry leads to stable opinion, a state of belief that need not later be given up. Peirce regarded the ultimate stability of opinion as a criterion of truth and reality: “the real . . . is that which, sooner or later, information and reasoning would finally result in, and which is therefore independent of the vagaries of you and me.” He accepted, however, an objectivist conception of truth and reality: the defining characteristic of reality is its independence of the opinions of individual persons. In “The Fixation of Belief” Peirce argued that the scientific method, a method in which we let our beliefs be determined by external reality, “by something upon which our thinking has no effect,” is the best way of settling opinion. Much of his philosophical work was devoted to the analysis of the various forms of inference and argument employed in science. He studied the concept of probability and probabilistic reasoning in science, criticized the subjectivist view of probability, and adopted an objectivist conception, according to which probability can be defined as a relative frequency in the long run. Peirce distinguished between three main types of inference, which correspond to three stages of inquiry: i abduction, a tentative acceptance of an explanatory hypothesis which, if true, would make the phenomenon under investigation intelligible; ii deduction, the derivation of testable consequences from the explanatory hypothesis; and iii induction, the evaluation of the hypothesis in the light of these consequences. He called this method of inquiry the inductive method; in the contemporary philosophy of science it is usually called the hypothetico-deductive method. According to Peirce, the scientific method can be viewed as an application of the pragmatic maxim: the testable consequences derived from an explanatory hypothesis constitute its concrete “meaning” in the sense of the Pragmatic Maxim. Thus the Maxim determines the admissibility of a hypothesis as a possible meaningful explanation. According to Pierce, inquiry is always dependent on beliefs that are not subject to doubt at the time of the inquiry, but such beliefs might be questioned on some other occasion. Our knowledge does not rest on indubitable “first premises,” but all beliefs are dependent on other beliefs. According to Peirce’s doctrine of fallibilism, the conclusions of science are always tentative. The rationality of the scientific method does not depend on the certainty of its conclusions, but on its self-corrective character: by continued application of the method science can detect and correct its own mistakes, and thus eventually lead to the discovery of truth. Logic, the theory of signs, and the philosophy of language. In “The Logic of Relatives,” published in 1883 in a collection of papers by himself and his students at the Johns Hopkins  Studies in Logic by Members of the Johns Hopkins , Peirce formalized relational statements by using subscript indices for individuals individual variables, and construed the quantifiers ‘some’ and ‘every’ as variable binding operators; thus Peirce can be regarded together Peirce, Charles Sanders Peirce, Charles Sanders 652    652 with the German logician Frege as one of the founders of quantification theory predicate logic. In his paper “On the Algebra of Logic  A Contribution to the Philosophy of Notation” 1885 he interpreted propositional logic as a calculus of truth-values, and defined logically necessary truth in propositional logic as truth for all truth-value assignments to sentential letters. He studied the logic of modalities and in the 1890s he invented a system of logical graphs called “existential graphs”, based on a diagrammatic representation of propositions, in which he anticipated some basic ideas of the possible worlds semantics of modal logic. Peirce’s letters and notebooks contain significant logical and philosophical insights. For example, he examined three-valued truth tables “Triadic Logic”, and discovered in 1886 the possibility of representing the truth-functional connectives of propositional logic by electrical switching circuits. Peirce regarded logic as a part of a more general area of inquiry, the theory of signs, which he also called semeiotic nowadays usually spelled ‘semiotics’. According to Peirce, sign relations are triadic, involving the sign itself, its object or what the sign stands for, and an interpretant which determines how the sign represents the object; the interpretant can be regarded as the meaning of the sign. The interpretant of a sign is another sign which in turn has its own interpretant or interpretants; such a sequence of interpretants ends in an “ultimate logical interpretant,” which is “a change of habit of conduct.” On the basis of the triadic character of the sign relation Peirce distinguished three divisions of signs. These divisions were based on i the character of the sign itself, ii the relation between the sign and its object, and iii the way in which the interpretant represents the object. These divisions reflect Peirce’s system of three fundamental ontological categories, which he termed Quality or Firstness, Relation or Secondness, and Representation or Thirdness. Thus, according to the first division, a sign can be a a qualisign, a mere quality or appearance a First; b a sinsign or token, an individual object, or event a Second; or c a legisign or a general type a Third. Secondly, signs can be divided into icons, indices, and symbols on the basis of their relations to their objects: an icon refers to an object on the basis of its similarity to the object in some respect; an index stands in a dynamic or causal relation to its object; whereas a symbol functions as a sign of an object by virtue of a rule or habit of interpretation. Peirce’s third division divides signs into rhemes predicative signs, propositional signs propositions, and arguments. Some of the concepts and distinctions introduced by Peirce, e.g., the distinction between “types” and “tokens” and the division of signs into “icons,” “indices,” and “symbols,” have become part of the standard conceptual repertoire of philosophy and semiotics. In his philosophy of language Peirce made a distinction between a proposition and an assertion, and studied the logical character of assertive speech acts. Metaphysics. In spite of his critical attitude toward traditional metaphysics, Peirce believed that metaphysical questions can be discussed in a meaningful way. According to Peirce, metaphysics studies the most general traits of reality, and “kinds of phenomena with which every man’s experience is so saturated that he usually pays no particular attention to them.” The basic categories of Firstness, Secondness, and Thirdness mentioned above occupy a central position in Peirce’s metaphysics. Especially in his later writings he emphasized the reality and metaphysical irreducibility of Thirdness, and defended the view that general phenomena for example, general laws cannot be regarded as mere conjunctions of their actual individual instances. This view was associated with Peirce’s synechism, the doctrine that the world contains genuinely continuous phenomena. He regarded synechism as a new form of Scholastic realism. In the area of modalities Peirce’s basic categories appear as possibility, actuality, and necessity. Here he argued that reality cannot be identified with existence or actuality, but comprises real objective possibilities. This view was partly based on his realization that many conditional statements, for instance the “practical” conditionals expressing the empirical import of a proposition in the sense of the Pragmatic Maxim, cannot be construed as material or truth-functional conditionals, but must be regarded as modal subjunctive conditionals. In his cosmology Peirce propounded the doctrine of tychism, according to which there is absolute chance in the universe, and the basic laws of nature are probabilistic and inexact. Peirce’s position in contemporary philosophy. Peirce had few disciples, but some of his students and colleagues became influential figures in American philosophy and science, e.g., the philosophers James, Royce, and Dewey and the economist Thorstein Veblen. Peirce’s pragmatism Peirce, Charles Sanders Peirce, Charles Sanders 653    653 became widely known through James’s lectures and writings, but Peirce was dissatisfied with James’s version of pragmatism, and renamed his own form of it ‘pragmaticism’, which term he considered to be “ugly enough to keep it safe from kidnappers.” Pragmatism became an influential philosophical movement during the twentieth century through Dewey philosophy of science and philosophy of education, C. I. Lewis theory of knowledge, Ramsey, Ernest Nagel, and Quine philosophy of science. Peirce’s work in logic influenced, mainly through his contacts with the German logician Ernst Schröder, the model-theoretic tradition in twentieth-century logic. There are three comprehensive collections of Peirce’s papers: Collected Papers of Charles Sanders Peirce 193158, vols. 16 edited by Charles Hartshorne and Paul Weiss, vols. 78 edited by Arthur Burks; The New Elements of Mathematics by Charles S. Peirce 1976, edited by Carolyn Eisele; and Writings of Charles S. Peirce: A Chronological Edition 1982. 

Peirce’s law, the principle ‘A P B P A P A’, which holds in classical logic but fails in the eyes of relevance logicians when ‘ P’ is read as ‘entails’.

Pelagianism, the doctrine in Christian theology that, through the exercise of free will, human beings can attain moral perfection. A broad movement devoted to this proposition was only loosely associated with its eponymous leader. Pelagius c.354c.425, a lay theologian from Britain or Ireland, taught in Rome prior to its sacking in 410. He and his disciple Celestius found a forceful adversary in Augustine, whom they provoked to stiffen his stance on original sin, the bondage of the will, and humanity’s total reliance upon God’s grace and predestination for salvation. To Pelagius, this constituted fatalism and encouraged moral apathy. God would not demand perfection, as the Bible sometimes suggested, were that impossible to attain. Rather grace made the struggle easier for a sanctity that would not be unreachable even in its absence. Though in the habit of sinning, in consequence of the fall, we have not forfeited the capacity to overcome that habit nor been released from the imperative to do so. For all its moral earnestness this teaching seems to be in conflict with much of the New Testament, especially as interpreted by Augustine, and it was condemned as heresy in 418. The bondage of the will has often been reaffirmed, perhaps most notably by Luther in dispute with Erasmus. Yet Christian theology and practice have always had their sympathizers with Pelagianism and with its reluctance to attest the loss of free will, the inevitability of sin, and the utter necessity of God’s grace.

per accidens Latin, ‘by accident’, by, as, or being an accident or non-essential feature. A per accidens predication is one in which an accident is predicated of a substance. The terminology is medieval. Note that the accident and substance themselves, not words standing for them, are the terms of the predication relation. An ens entity per accidens is either an accident or the “accidental unity” of a substance and an accident Descartes, e.g., insists that a person is not a per accidens union of body and mind.

perception, the extraction and use of information about one’s environment exteroception and one’s own body interoception. The various external senses  sight, hearing, touch, smell, and taste  though they overlap to some extent, are distinguished by the kind of information e.g., about light, sound, temperature, pressure they deliver. Proprioception, perception of the self, concerns stimuli arising within, and carrying information about, one’s own body  e.g., acceleration, position, and orientation of the limbs. There are distinguishable stages in the extraction and use of sensory information, one an earlier stage corresponding to our perception of objects and events, the other, a later stage, to the perception of facts about these objects. We see, e.g., both the cat on the sofa an object and that the cat is on the sofa a fact. Seeing an object or event  a cat on the sofa, a person on the street, or a vehicle’s movement  does not require that the object event be identified or recognized in any particular way perhaps, though this is controversial, in any way whatsoever. One can, e.g., see a cat on the sofa and mistake it for a rumpled sweater. Airplane lights are often misidentified as stars, and one can see the movement of an object either as the movement of oneself or under some viewing conditions as Peirce’s law perception 654    654 expansion or contraction. Seeing objects and events is, in this sense, non-epistemic: one can see O without knowing or believing that it is O that one is seeing. Seeing facts, on the other hand, is epistemic; one cannot see that there is a cat on the sofa without, thereby, coming to know that there is a cat on the sofa. Seeing a fact is coming to know the fact in some visual way. One can see objects  the fly in one’s soup, e.g.,  without realizing that there is a fly in one’s soup thinking, perhaps, it is a bean or a crouton; but to see a fact, the fact that there is a fly in one’s soup is, necessarily, to know it is a fly. This distinction applies to the other sense modalities as well. One can hear the telephone ringing without realizing that it is the telephone perhaps it’s the TV or the doorbell, but to hear a fact, that it is the telephone that is ringing, is, of necessity, to know that it is the telephone that is ringing. The other ways we have of describing what we perceive are primarily variations on these two fundamental themes. In seeing where he went, when he left, who went with him, and how he was dressed, e.g., we are describing the perception of some fact of a certain sort without revealing exactly which fact it is. If Martha saw where he went, then Martha saw hence, came to know some fact having to do with where he went, some fact of the form ‘he went there’. In speaking of states and conditions the condition of his room, her injury, and properties the color of his tie, the height of the building, we sometimes, as in the case of objects, mean to be describing a non-epistemic perceptual act, one that carries no implications for what if anything is known. In other cases, as with facts, we mean to be describing the acquisition of some piece of knowledge. One can see or hear a word without recognizing it as a word it might be in a foreign language, but can one see a misprint and not know it is a misprint? It obviously depends on what one uses ‘misprint’ to refer to: an object a word that is misprinted or a fact the fact that it is misprinted. In examining and evaluating theories whether philosophical or psychological of perception it is essential to distinguish fact perception from object perception. For a theory might be a plausible theory about the perception of objects e.g., psychological theories of “early vision” but not at all plausible about our perception of facts. Fact perception, involving, as it does, knowledge and, hence, belief brings into play the entire cognitive system memory, concepts, etc. in a way the former does not. Perceptual relativity  e.g., the idea that what we perceive is relative to our language, our conceptual scheme, or the scientific theories we have available to “interpret” phenomena  is quite implausible as a theory about our perception of objects. A person lacking a word for, say, kumquats, lacking this concept, lacking a scientific way of classifying these objects are they a fruit? a vegetable? an animal?, can still see, touch, smell, and taste kumquats. Perception of objects does not depend on, and is therefore not relative to, the observer’s linguistic, conceptual, cognitive, and scientific assets or shortcomings. Fact perception, however, is another matter. Clearly one cannot see that there are kumquats in the basket as opposed to seeing the objects, the kumquats, in the basket if one has no idea of, no concept of, what a kumquat is. Seeing facts is much more sensitive and, hence, relative to the conceptual resources, the background knowledge and scientific theories, of the observer, and this difference must be kept in mind in evaluating claims about perceptual relativity. Though it does not make objects invisible, ignorance does tend to make facts perceptually inaccessible. There are characteristic experiences associated with the different senses. Tasting a kumquat is not at all like seeing a kumquat although the same object is perceived indeed, the same fact  that it is a kumquat  may be perceived. The difference, of course, is in the subjective experience one has in perceiving the kumquat. A causal theory of perception of objects holds that the perceptual object, what it is we see, taste, smell, or whatever, is that object that causes us to have this subjective experience. Perceiving an object is that object’s causing in the right way one to have an experience of the appropriate sort. I see a bean in my soup if it is, in fact whether I know it or not is irrelevant, a bean in my soup that is causing me to have this visual experience. I taste a bean if, in point of fact, it is a bean that is causing me to have the kind of taste experience I am now having. If it is unknown to me a bug, not a bean, that is causing these experiences, then I am unwittingly seeing and tasting a bug  perhaps a bug that looks and tastes like a bean. What object we see taste, smell, etc. is determined by the causal facts in question. What we know and believe, how we interpret the experience, is irrelevant, although it will, of course, determine what we say we see and taste. The same is to be said, with appropriate changes, for our perception of facts the most significant change being the replacement of belief for experience. I see that there is a bug in my soup if the fact that there is a bug in my soup causes me to perception perception 655    655 believe that there is a bug in my soup. I can taste that there is a bug in my soup when this fact causes me to have this belief via some taste sensation. A causal theory of perception is more than the claim that the physical objects we perceive cause us to have experiences and beliefs. This much is fairly obvious. It is the claim that this causal relation is constitutive of perception, that necessarily, if S sees O, then O causes a certain sort of experience in S. It is, according to this theory, impossible, on conceptual grounds, to perceive something with which one has no causal contact. If, e.g., future events do not cause present events, if there is no backward causation, then we cannot perceive future events and objects. Whether or not future facts can be perceived or known depends on how liberally the causal condition on knowledge is interpreted. Though conceding that there is a world of mind-independent objects trees, stars, people that cause us to have experiences, some philosophers  traditionally called representative realists  argue that we nonetheless do not directly perceive these external objects. What we directly perceive are the effects these objects have on us  an internal image, idea, or impression, a more or less depending on conditions of observation accurate representation of the external reality that helps produce it. This subjective, directly apprehended object has been called by various names: a sensation, percept, sensedatum, sensum, and sometimes, to emphasize its representational aspect, Vorstellung German, ‘representation’. Just as the images appearing on a television screen represent their remote causes the events occurring at some distant concert hall or playing field, the images visual, auditory, etc. that occur in the mind, the sensedata of which we are directly aware in normal perception, represent or sometimes, when things are not working right, misrepresent their external physical causes. The representative realist typically invokes arguments from illusion, facts about hallucination, and temporal considerations to support his view. Hallucinations are supposed to illustrate the way we can have the same kind of experience we have when as we commonly say we see a real bug without there being a real bug in our soup or anywhere else causing us to have the experience. When we hallucinate, the bug we “see” is, in fact, a figment of our own imagination, an image i.e., sense-datum in the mind that, because it shares some of the properties of a real bug shape, color, etc., we might mistake for a real bug. Since the subjective experiences can be indistinguishable from that which we have when as we commonly say we really see a bug, it is reasonable to infer the representative realist argues that in normal perception, when we take ourselves to be seeing a real bug, we are also directly aware of a buglike image in the mind. A hallucination differs from a normal perception, not in what we are aware of in both cases it is a sense-datum but in the cause of these experiences. In normal perception it is an actual bug; in hallucination it is, say, drugs in the bloodstream. In both cases, though, we are caused to have the same thing: an awareness of a buglike sense-datum, an object that, in normal perception, we naively take to be a real bug thus saying, and encouraging our children to say, that we see a bug. The argument from illusion points to the fact that our experience of an object changes even when the object that we perceive or say we perceive remains unchanged. Though the physical object the bug or whatever remains the same color, size, and shape, what we experience according to this argument changes color, shape, and size as we change the lighting, our viewing angle, and distance. Hence, it is concluded, what we experience cannot really be the physical object itself. Since it varies with changes in both object and viewing conditions, what we experience must be a causal result, an effect, of both the object we commonly say we see the bug and the conditions in which we view it. This internal effect, it is concluded, is a sense-datum. Representative realists have also appealed to the fact that perceiving a physical object is a causal process that takes time. This temporal lag is most dramatic in the case of distant objects e.g., stars, but it exists for every physical object it takes time for a neural signal to be transmitted from receptor surfaces to the brain. Consequently, at the moment a short time after light leaves the object’s surface we see a physical object, the object could no longer exist. It could have ceased to exist during the time light was being transmitted to the eye or during the time it takes the eye to communicate with the brain. Yet, even if the object ceases to exist before we become aware of anything before a visual experience occurs, we are, or so it seems, aware of something when the causal process reaches its climax in the brain. This something of which we are aware, since it cannot be the physical object it no longer exists, must be a sense-datum. The representationalist concludes in this “time-lag argument,” therefore, that even when the physperception perception 656    656 ical object does not cease to exist this, of course, is the normal situation, we are directly aware, not of it, but of its slightly later-occurring representation. Representative realists differ among themselves about the question of how much if at all the sense-data of which we are aware resemble the external objects of which we are not aware. Some take the external cause to have some of the properties the so-called primary properties of the datum e.g., extension and not others the so-called secondary properties  e.g., color. Direct or naive realism shares with representative realism a commitment to a world of independently existing objects. Both theories are forms of perceptual realism. It differs, however, in its view of how we are related to these objects in ordinary perception. Direct realists deny that we are aware of mental intermediaries sensedata when, as we ordinarily say, we see a tree or hear the telephone ring. Though direct realists differ in their degree of naïveté about how and in what respect perception is supposed to be direct, they need not be so naive as sometimes depicted as to deny the scientific facts about the causal processes underlying perception. Direct realists can easily admit, e.g., that physical objects cause us to have experiences of a particular kind, and that these experiences are private, subjective, or mental. They can even admit that it is this causal relationship between object and experience that constitutes our seeing and hearing physical objects. They need not, in other words, deny a causal theory of perception. What they must deny, if they are to remain direct realists, however, is an analysis of the subjective experience that objects cause us to have into an awareness of some object. For to understand this experience as an awareness of some object is, given the wholly subjective mental character of the experience itself, to interpose a mental entity what the experience is an awareness of between the perceiver and the physical object that causes him to have this experience, the physical object that is supposed to be directly perceived. Direct realists, therefore, avoid analyzing a perceptual experience into an act sensing, being aware of, being acquainted with and an object the sensum, sense-datum, sensation, mental representation. The experience we are caused to have when we perceive a physical object or event is, instead, to be understood in some other way. The adverbial theory is one such possibility. As the name suggests, this theory takes its cue from the way nouns and adjectives can sometimes be converted into adverbs without loss of descriptive content. So, for instance, it comes to pretty much the same thing whether we describe a conversation as animated adjective or say that we conversed animatedly an adverb. So, also, according to an adverbialist, when, as we commonly say, we see a red ball, the red ball causes in us a moment later an experience, yes, but not as the representative realist says an awareness mental act of a sense-datum mental object that is red and circular adjectives. The experience is better understood as one in which there is no object at all, as sensing redly and circularly adverbs. The adverbial theorist insists that one can experience circularly and redly without there being, in the mind or anywhere else, red circles this, in fact, is what the adverbialist thinks occurs in dreams and hallucinations of red circles. To experience redly is not to have a red experience; nor is it to experience redness in the mind. It is, says the adverbialist, a way or a manner of perceiving ordinary objects especially red ones seen in normal light. Just as dancing gracefully is not a thing we dance, so perceiving redly is not a thing  and certainly not a red thing in the mind  that we experience. The adverbial theory is only one option the direct realist has of acknowledging the causal basis of perception while, at the same time, maintaining the directness of our perceptual relation with independently existing objects. What is important is not that the experience be construed adverbially, but that it not be interpreted, as representative realists interpret it, as awareness of some internal object. For a direct realist, the appearances, though they are subjective mind-dependent are not objects that interpose themselves between the conscious mind and the external world. As classically understood, both naive and representative realism are theories about object perception. They differ about whether it is the external object or an internal object an idea in the mind that we most directly apprehend in ordinary sense perception. But they need not although they usually do differ in their analysis of our knowledge of the world around us, in their account of fact perception. A direct realist about object perception may, e.g., be an indirect realist about the facts that we know about these objects. To see, not only a red ball in front of one, but that there is a red ball in front of one, it may be necessary, even on a direct theory of object perception, to infer or in some way derive this fact from facts that are known more directly perception perception about one’s experiences of the ball. Since, e.g., a direct theorist may be a causal theorist, may think that seeing a red ball is in part constituted by the having of certain sorts of experience, she may insist that knowledge of the cause of these experiences must be derived from knowledge of the experience itself. If one is an adverbialist, e.g., one might insist that knowledge of physical objects is derived from knowledge of how redly? bluely? circularly? squarely? one experiences these objects. By the same token, a representative realist could adopt a direct theory of fact perception. Though the objects we directly see are mental, the facts we come to know by experiencing these subjective entities are facts about ordinary physical objects. We do not infer at least at no conscious level that there is a bug in our soup from facts known more directly about our own conscious experiences from facts about the sensations the bug causes in us. Rather, our sensations cause us, directly, to have beliefs about our soup. There is no intermediate belief; hence, there is no intermediate knowledge; hence, no intermediate fact perception. Fact perception is, in this sense, direct. Or so a representative realist can maintain even though committed to the indirect perception of the objects bug and soup involved in this fact. This merely illustrates, once again, the necessity of distinguishing object perception from fact perception. 

Percival, Thomas 17401804, English physician and author of Medical Ethics 1803. He was central in bringing the Western traditions of medical ethics from prayers and oaths e.g., the Hippocratic oath toward more detailed, modern codes of proper professional conduct. His writing on the normative aspects of medical practice was part ethics, part prudential advice, part professional etiquette, and part jurisprudence. Medical Ethics treated standards for the professional conduct of physicians relative to surgeons and apothecaries pharmacists and general practitioners, as well as hospitals, private practice, and the law. The issues Percival addressed include privacy, truth telling, rules for professional consultation, human experimentation, public and private trust, compassion, sanity, suicide, abortion, capital punishment, and environmental nuisances. Percival had his greatest influence in England and America. At its founding in 1847, the American Medical Association used Medical Ethics to guide its own first code of medical ethics.

perdurance, in one common philosophical use, the property of being temporally continuous and having temporal parts. There are at least two conflicting theories about temporally continuous substances. According to the first, temporally continuous substances have temporal parts they perdure, while according to the second, they do not. In one ordinary philosophical use, endurance is the property of being temporally continuous and not having temporal parts. There are modal versions of the aforementioned two theories: for example, one version of the first theory is that necessarily, temporally continuous substances have temporal parts, while another version implies that possibly, they do not. Some versions of the first theory hold that a temporally continuous substance is composed of instantaneous temporal parts or “object-stages,” while on other versions these object-stages are not parts but boundaries. 

perfect competition, the state of an ideal market under the following conditions: a every consumer in the market is a perfectly rational maximizer of utility; b every producer is a perfect maximizer of profit; c there is a very large ideally infinite number of producers of the good in question, which ensures that no producer can set the price for its output otherwise, an imperfect competitive state of oligopoly or monopoly obtains; and d every producer provides a product perfectly indistinguishable from that of other producers if consumers could distinguish products to the point that there was no longer a very large number of producers for each distinguishable good, competition would again be imperfect. Under these conditions, the market price is equal to the marginal cost of producing the last unit. This in turn determines the market supply of the good, since each producer will gain by increasing production when price exceeds marginal cost and will generally cut losses by decreasing production when marginal cost exceeds price. Perfect competition is sometimes perceptual realism perfect competition 658    658 thought to have normative implications for political philosophy, since it results in Pareto optimality. The concept of perfect competition becomes extremely complicated when a market’s evolution is considered. Producers who cannot equate marginal cost with the market price will have negative profit and must drop out of the market. If this happens very often, then the number of producers will no longer be large enough to sustain perfect competition, so new producers will need to enter the market. 

perfectionism, an ethical view according to which individuals and their actions are judged by a maximal standard of achievement  specifically, the degree to which they approach ideals of aesthetic, intellectual, emotional, or physical “perfection.” Perfectionism, then, may depart from, or even dispense with, standards of conventional morality in favor of standards based on what appear to be non-moral values. These standards reflect an admiration for certain very rare levels of human achievement. Perhaps the most characteristic of these standards are artistic and other forms of creativity; but they prominently include a variety of other activities and emotional states deemed “noble”  e.g., heroic endurance in the face of great suffering. The perfectionist, then, would also tend toward a rather non-egalitarian  even aristocratic  view of humankind. The rare genius, the inspired few, the suffering but courageous artist  these examples of human perfection are genuinely worthy of our estimation, according to this view. Although no fully worked-out system of “perfectionist philosophy” has been attempted, aspects of all of these doctrines may be found in such philosophers as Nietzsche. Aristotle, as well, appears to endorse a perfectionist idea in his characterization of the human good. Just as the good lyre player not only exhibits the characteristic activities of this profession but achieves standards of excellence with respect to these, the good human being, for Aristotle, must achieve standards of excellence with respect to the virtue or virtues distinctive of human life in general. 

Peripatetic School, also called Peripatos, the philosophical community founded by Aristotle at a public gymnasium the Lyceum after his return to Athens in c.335 B.C. The derivation of ‘Peripatetic’ from the alleged Aristotelian custom of “walking about” peripatein is probably wrong. The name should be explained by reference to a “covered walking hall” peripatos among the school facilities. A scholarch or headmaster presided over roughly two classes of members: the presbyteroi or seniors, who probably had some teaching duties, and the neaniskoi or juniors. No evidence of female philosophers in the Lyceum has survived. During Aristotle’s lifetime his own lectures, whether for the inner circle of the school or for the city at large, were probably the key attraction and core activity; but given Aristotle’s knack for organizing group research projects, we may assume that young and old Peripatetics spent much of their time working on their own specific assignments either at the library, where they could consult works of earlier writers, or at some kind of repository for specimens used in zoological and botanical investigations. As a resident alien, Aristotle could not own property in Athens and hence was not the legal owner of the school. Upon his final departure from Athens in 322, his longtime collaborator Theophrastus of Eresus in Lesbos c.370287 succeeded him as scholarch. Theophrastus was an able Aristotelian who wrote extensively on metaphysics, psychology, physiology, botany, ethics, politics, and the history of philosophy. With the help of the Peripatetic dictator Demetrius of Phaleron, he was able to secure property rights over the physical facilities of the school. Under Theophrastus, the Peripatos continued to flourish and is said to have had 2,000 students, surely not all at the same time. His successor, Strato of Lampsakos c.335269, had narrower interests and abandoned key Aristotelian tenets. With him a progressive decline set in, to which the early loss of Aristotle’s personal library, taken to Asia Minor perfect duty Peripatetic School 659    659 by Neleus of Skepsis, certainly contributed. By the first century B.C. the Peripatos had ceased to exist. Philosophers of later periods sympathetic to Aristotle’s views have also been called Peripatetics. 

Perry, Ralph Barton 18761957, American philosopher who taught at Harvard  and wrote extensively in ethics, social philosophy, and the theory of knowledge. He received a Pulitzer Prize in 1936 for The Thought and Character of William James, a biography of his teacher and colleague. Perry’s other major works include: The Moral Economy 1909, General Theory of Value 1926, Puritanism and Democracy 1944, and Realms of Value 1954. He is perhaps best known for his views on value. He writes in General Theory of Value, “Any object, whatever it be, acquires value when any interest, whatever it be, is taken in it; just as anything whatsoever becomes a target when anyone whosoever aims at it.” Something’s having value is nothing but its being the object of some interest, and to know whether it has value one need only know whether it is the object of someone’s interest. Morality aims at the promotion of the moral good, which he defines as “harmonious happiness.” This consists in the reconciliation, harmonizing, and fulfillment of all interests. Perry’s epistemological and metaphysical views were part of a revolt against idealism and dualism. Along with five other philosophers, he wrote The New Realism 1912. The “New Realists” held that the objects of perception and memory are directly presented to consciousness and are just what they appear to be; nothing intervenes between the knower and the external world. The view that the objects of perception and memory are presented by means of ideas leads, they argued, to idealism, skepticism, and absurdity. Perry is also known for having developed, along with E. B. Holt, the “specific response” theory, which is an attempt to construe belief and perception in terms of bodily adjustment and behavior. 

personal identity, the numerical identity over time of persons. The question of what personal identity consists in is the question of what it is what the necessary and sufficient conditions are for a person existing at one time and a person existing at another time to be one and the same person. Here there is no question of there being any entity that is the “identity” of a person; to say that a person’s identity consists in such and such is just shorthand for saying that facts about personal identity, i.e., facts to the effect that someone existing at one time is the same as someone existing at another time, consist in such and such. This should not be confused with the usage, common in ordinary speech and in psychology, in which persons are said to have identities, and, sometimes, to seek, lose, or regain their identities, where one’s “identity” intimately involves a set of values and goals that structure one’s life. The words ‘identical’ and ‘same’ mean nothing different in judgments about persons than in judgments about other things. The problem of personal identity is therefore not one of defining a special sense of ‘identical,’ and it is at least misleading to characterize it as defining a particular kind of identity. Applying Quine’s slogan “no entity without identity,” one might say that characterizing any sort of entity involves indicating what the identity conditions for entities of that sort are so, e.g., part of the explanation of the concept of a set is that sets having the same members are identical, and that asking what the identity of persons consists in is just a way of asking what sorts of things persons are. But the main focus in traditional discussions of the topic has been on one kind of identity judgment about persons, namely those asserting “identity over time”; the question has been about what the persistence of persons over time consists in. What has made the identity persistence of persons of special philosophical interest is partly its epistemology and partly its connections with moral and evaluative matters. The crucial epistemological fact is that persons have, in memory, an access to their own past histories that is unlike the access they have to the histories of other things including other persons; when one remembers doing or experiencing something, one normally has no need to employ any criterion of identity in order to know that the subject of the remembered action or experience is i.e., is identical with oneself. The moral and evaluative matters include moral responsibility someone can be held responsible for a past action only Peripatos personal identity 660    660 if he or she is identical to the person who did it and our concern for our own survival and future well-being since it seems, although this has been questioned, that what one wants in wanting to survive is that there should exist in the future someone who is identical to oneself. The modern history of the topic of personal identity begins with Locke, who held that the identity of a person consists neither in the identity of an immaterial substance as dualists might be expected to hold nor in the identity of a material substance or “animal body” as materialists might be expected to hold, and that it consists instead in “same consciousness.” His view appears to have been that the persistence of a person through time consists in the fact that certain actions, thoughts, experiences, etc., occurring at different times, are somehow united in memory. Modern theories descended from Locke’s take memory continuity to be a special case of something more general, psychological continuity, and hold that personal identity consists in this. This is sometimes put in terms of the notion of a “person-stage,” i.e., a momentary “time slice” of the history of a person. A series of person-stages will be psychologically continuous if the psychological states including memories occurring in later members of the series grow out of, in certain characteristic ways, those occurring in earlier members of it; and according to the psychological continuity view of personal identity, person-stages occurring at different times are stages of the same person provided they belong to a single, non-branching, psychologically continuous series of person-stages. Opponents of the Lockean and neo-Lockean psychological continuity view tend to fall into two camps. Some, following Butler and Reid, hold that personal identity is indefinable, and that nothing informative can be said about what it consists in. Others hold that the identity of a person consists in some sort of physical continuity  perhaps the identity of a living human organism, or the identity of a human brain. In the actual cases we know about putting aside issues about non-bodily survival of death, psychological continuity and physical continuity go together. Much of the debate between psychological continuity theories and physical continuity theories has centered on the interpretation of thought experiments involving brain transplants, brain-state transfers, etc., in which these come apart. Such examples make vivid the question of whether our fundamental criteria of personal identity are psychological, physical, or both. Recently philosophical attention has shifted somewhat from the question of what personal identity consists in to questions about its importance. The consideration of hypothetical cases of “fission” in which two persons at a later time are psychologically continuous with one person at an earlier time has suggested to some that we can have survival  or at any rate what matters in survival  without personal identity, and that our self-interested concern for the future is really a concern for whatever future persons are psychologically continuous with us. 

personalism, a version of personal idealism that flourished in the United States principally at Boston  from the late nineteenth century to the mid-twentieth century. Its principal proponents were Borden Parker Bowne 1847 1910 and three of his students: Albert Knudson 18731953; Ralph Flewelling 18711960, who founded The Personalist; and, most importantly, Edgar Sheffield Brightman 18841953. Their personalism was both idealistic and theistic and was influential in philosophy and in theology. Personalism traced its philosophical lineage to Berkeley and Leibniz, and had as its foundational insight the view that all reality is ultimately personal. God is the transcendent person and the ground or creator of all other persons; nature is a system of objects either for or in the minds of persons. Both Bowne and Brightman considered themselves empiricists in the tradition of Berkeley. Immediate experience is the starting point, but this experience involves a fundamental knowledge of the self as a personal being with changing states. Given this pluralism, the coherence, order, and intelligibility of the universe are seen to derive from God, the uncreated person. Bowne’s God is the eternal and omnipotent being of classical theism, but Brightman argued that if God is a real person he must be construed as both temporal and finite. Given the fact of evil, God is seen as gradually gaining control over his created world, with regard to which his will is intrinsically limited. Another version of personalism developed in France out of the neo-Scholastic tradition. E. Mounier 190550, Maritain, and Gilson identified themselves as personalists, inasmuch as they viewed the infinite person God and finite persons as the source and locus of intrinsic value. They did not, however, view the natural order as intrinsically personal.

personhood, the condition or property of being a person, especially when this is considered to entail moral and/or metaphysical importance. Personhood has been thought to involve various traits, including moral agency; reason or rationality; language, or the cognitive skills language may support such as intentionality and self-consciousness; and ability to enter into suitable relations with other persons viewed as members of a self-defining group. Buber emphasized the difference between the I-It relationship holding between oneself and an object, and the IThou relationship, which holds between oneself and another person who can be addressed. Dennett has construed persons in terms of the “intentional stance,” which involves explaining another’s behavior in terms of beliefs, desires, intentions, etc. Questions about when personhood begins and when it ends have been central to debates about abortion, infanticide, and euthanasia, since personhood has often been viewed as the mark, if not the basis, of a being’s possession of special moral status. 

Peter Lombard c.10951160, Italian theologian and author of the Book of Sentences Liber sententiarum, a renowned theological sourcebook in the later Middle Ages. Peter was educated at Bologna, Reims, and Paris before teaching in the school of Notre Dame in Paris. He became a canon at Notre Dame in 114445 and was elected bishop of Paris in 1159. His extant works include commentaries on the Psalms written in the mid-1130s and on the epistles of Paul c.113941; a collection of sermons; and his one-volume summary of Christian doctrine, the Sentences completed by 1158. The Sentences consists of four books: Book I, On the Trinity; Book II, On the Creation of Things; Book III, On the Incarnation; and Book IV, On the Doctrine of Signs or Sacraments. His discussion is organized around particular questions or issues e.g., “On Knowledge, Foreknowledge, and Providence” Book I, “Is God the Cause of Evil and Sin?” Book II. For a given issue Peter typically presents a brief summary, accompanied by short quotations, of main positions found in Scripture and in the writings of the church fathers and doctors, followed by his own determination or adjudication of the matter. Himself a theological conservative, Peter seems to have intended this sort of compilation of scriptural and ancient doctrinal teaching as a counter to the popularity, fueled by the recent recovery of important parts of Aristotle’s logic, of the application of dialectic to theological matters. The Sentences enjoyed wide circulation and admiration from the beginning, and within a century of its composition it became a standard text in the theology curriculum. From the midthirteenth through the mid-fourteenth century every student of theology was required, as the last stage in obtaining the highest academic degree, to lecture and comment on Peter’s text. Later medieval thinkers often referred to Peter as “the Master” magister, thereby testifying to the Sentences’ preeminence in theological training. In lectures and commentaries, the greatest minds of this period used Peter’s text as a framework in which to develop their own original positions and debate with their contemporaries. As a result the Sentences-commentary tradition is an extraordinarily rich repository of later medieval philosophical and theological thought. S.Ma. Peter of Spain. It is now thought that there were two Peters of Spain. The Spanish prelate and philosopher c.120577 was born in Lisbon, studied at Paris, and taught medicine at Siena 124850. He served in various ecclesiastical posts in Portugal and Italy 125073 before being elected pope as John XXI in 1276. He wrote several books on philosophical psychology and compiled the famous medical work Thesaurus pauperum. The second Peter of Spain was a Spanish Dominican who lived during the first half of the thirteenth century. His Tractatus, later called Summulae logicales, received over 166 printings during subsequent centuries. The Tractatus presents the essentials of Aristotelian logic propositions, universals, categories, syllogism, dialectical topics, and the sophistical fallacies and improves on the mnemonic verses of William Sherwood; he then introduces the subjects of the so-called parva logicalia supposition, relatives, ampliation, personality Peter of Spain 662    662 appellation, restriction, distribution, all of which were extensively developed in the later Middle Ages. There is not sufficient evidence to claim that Peter wrote a special treatise on consequences, but his understanding of conditionals as assertions of necessary connection undoubtedly played an important role in the rules of simple, as opposed to as-of-now, consequences.

phantasia Grecian, ‘appearance’, ‘imagination’, 1 the state we are in when something appears to us to be the case; 2 the capacity in virtue of which things appear to us. Although frequently used of conscious and imagistic experiences, ‘phantasia’ is not limited to such states; in particular, it can be applied to any propositional attitude where something is taken to be the case. But just as the English ‘appears’ connotes that one has epistemic reservations about what is actually the case, so ‘phantasia’ suggests the possibility of being misled by appearances and is thus often a subject of criticism. According to Plato, phantasia is a “mixture” of sensation and belief; in Aristotle, it is a distinct faculty that makes truth and falsehood possible. The Stoics take a phantasia to constitute one of the most basic mental states, in terms of which other mental states are to be explained, and in rational animals it bears the propositional content expressed in language. This last use becomes prominent in ancient literary and rhetorical theory to designate the ability of language to move us and convey subjects vividly as well as to range beyond the bounds of our immediate experience. Here lie the origins of the modern concept of imagination although not the Romantic distinction between fancy and imagination. Later Neoplatonists, such as Proclus, take phantasia to be necessary for abstract studies such as geometry, by enabling us to envision spatial relations. 

phenomenalism, the view that propositions asserting the existence of physical objects are equivalent in meaning to propositions asserting that subjects would have certain sequences of sensations were they to have certain others. The basic idea behind phenomenalism is compatible with a number of different analyses of the self or conscious subject. A phenomenalist might understand the self as a substance, a particular, or a construct out of actual and possible experience. The view also is compatible with any number of different analyses of the visual, tactile, auditory, olfactory, gustatory, and kinesthetic sensations described in the antecedents and consequents of the subjunctive conditionals that the phenomenalist uses to analyze physical object propositions as illustrated in the last paragraph. Probably the most common analysis of sensations adopted by traditional phenomenalists is a sense-datum theory, with the sense-data construed as mind-dependent entities. But there is nothing to prevent a phenomenalist from accepting an adverbial theory or theory of appearing instead. The origins of phenomenalism are difficult to trace, in part because early statements of the view were usually not careful. In his Dialogues, Berkeley hinted at phenomenalism when he had Philonous explain how he could reconcile an ontology containing only minds and ideas with the story of a creation that took place before the existence of people. Philonous imagines that if he had been present at the creation he should have seen things, i.e., had sensations, in the order described in the Bible. It can also be argued, however, that J. S. Mill in An Examination of Sir William Hamilton’s Philosophy was the first to put forth a clearly phenomenalistic analysis when he identified matter with the “permanent possibility of sensation.” When Mill explained what these permanent possibilities are, he typically used conditionals that describe the sensations one would have if one were placed in certain conditions. The attraction of classical phenomenalism grew with the rise of logical positivism and its acceptance of the verifiability criterion of meaning. Phenomenalists were usually foundationalists who were convinced that justified belief in the physical world rested ultimately on our noninferentially justified beliefs about our sensations. Implicitly committed to the view that only deductive and inductive inferences are legitimate, and further assuming that to be justified in believing one proposition P on the basis of another E, one must be justified in believing both E and that E makes P probable, the phenomenalist saw an insuperable difficulty in justifying belief in ordinary statements about the physical world given prevalent conceptions of physical petitio principii phenomenalism 663    663 objects. If all we ultimately have as our evidence for believing in physical objects is what we know about the occurrence of sensation, how can we establish sensation as evidence for the existence of physical objects? We obviously cannot deduce the existence of physical objects from any finite sequence of sensations. The sensations could, e.g., be hallucinatory. Nor, it seems, can we observe a correlation between sensation and something else in order to generate the premises of an inductive argument for the conclusion that sensations are reliable indicators of physical objects. The key to solving this problem, the phenomenalist argues, is to reduce assertions about the physical world to complicated assertions about the sequences of sensations a subject would have were he to have certain others. The truth of such conditionals, e.g., that if I have the clear visual impression of a cat, then there is one before me, might be mind-independent in the way in which one wants the truth of assertions about the physical world to be mind-independent. And to the phenomenalist’s great relief, it would seem that we could justify our belief in such conditional statements without having to correlate anything but sensations. Many philosophers today reject some of the epistemological, ontological, and metaphilosophical presuppositions with which phenomenalists approached the problem of understanding our relation to the physical world through sensation. But the argument that was historically most decisive in convincing many philosophers to abandon phenomenalism was the argument from perceptual relativity first advanced by Chisholm in “The Problem of Perception.” Chisholm offers a strategy for attacking any phenomenalistic analysis. The first move is to force the phenomenalist to state a conditional describing only sensations that is an alleged consequence of a physical object proposition. C. I. Lewis, e.g., in An Analysis of Knowledge and Valuation, claims that the assertion P that there is a doorknob before me and to the left entails C that if I were to seem to see a doorknob and seem to reach out and touch it then I would seem to feel it. Chisholm argues that if P really did entail C then there could be no assertion R that when conjoined with P did not entail C. There is, however, such an assertion: I am unable to move my limbs and my hands but am subject to delusions such that I think I am moving them; I often seem to be initiating a grasping motion but with no feeling of contacting anything. Chisholm argues, in effect, that what sensations one would have if one were to have certain others always depends in part on the internal and external physical conditions of perception and that this fact dooms any attempt to find necessary and sufficient conditions for the truth of a physical object proposition couched in terms that describe only connections between sensations. 

phenomenology, in the twentieth century, the philosophy developed by Husserl and some of his followers. The term has been used since the mideighteenth century and received a carefully defined technical meaning in the works of both Kant and Hegel, but it is not now used to refer to a homogeneous and systematically developed philosophical position. The question of what phenomenology is may suggest that phenomenology is one among the many contemporary philosophical conceptions that have a clearly delineated body of doctrines and whose essential characteristics can be expressed by a set of wellchosen statements. This notion is not correct, however. In contemporary philosophy there is no system or school called “phenomenology,” characterized by a clearly defined body of teachings. Phenomenology is neither a school nor a trend in contemporary philosophy. It is rather a movement whose proponents, for various reasons, have propelled it in many distinct directions, with the result that today it means different things to different people. While within the phenomenological movement as a whole there are several related currents, they, too, are by no means homogeneous. Though these currents have a common point of departure, they do not project toward the same destination. The thinking of most phenomenologists has changed so greatly that their respective views can be presented adequately only by showing them in their gradual development. This is true not only for Husserl, founder of the phenomenological movement, but also for such later phenomenologists as Scheler, N. Hartmann, Heidegger, Sartre, and Merleau-Ponty. To anyone who studies the phenomenological movement without prejudice the differences among its many currents are obvious. It has been phenomenal property phenomenology 664    664 said that phenomenology consists in an analysis and description of consciousness; it has been claimed also that phenomenology simply blends with existentialism. Phenomenology is indeed the study of essences, but it also attempts to place essences back into existence. It is a transcendental philosophy interested only in what is “left behind” after the phenomenological reduction is performed, but it also considers the world to be already there before reflection begins. For some philosophers phenomenology is speculation on transcendental subjectivity, whereas for others it is a method for approaching concrete existence. Some use phenomenology as a search for a philosophy that accounts for space, time, and the world, just as we experience and “live” them. Finally, it has been said that phenomenology is an attempt to give a direct description of our experience as it is in itself without taking into account its psychological origin and its causal explanation; but Husserl speaks of a “genetic” as well as a “constitutive” phenomenology. To some people, finding such an abundance of ideas about one and the same subject constitutes a strange situation; for others it is annoying to contemplate the “confusion”; and there will be those who conclude that a philosophy that cannot define its own scope does not deserve the discussion that has been carried on in its regard. In the opinion of many, not only is this latter attitude not justified, but precisely the opposite view defended by Thevenaz should be adopted. As the term ‘phenomenology’ signifies first and foremost a methodical conception, Thevenaz argues that because this method, originally developed for a very particular and limited end, has been able to branch out in so many varying forms, it manifests a latent truth and power of renewal that implies an exceptional fecundity. Speaking of the great variety of conceptions within the phenomenological movement, Merleau-Ponty remarked that the responsible philosopher must recognize that phenomenology may be practiced and identified as a manner or a style of thinking, and that it existed as a movement before arriving at a complete awareness of itself as a philosophy. Rather than force a living movement into a system, then, it seems more in keeping with the ideal of the historian as well as the philosopher to follow the movement in its development, and attempt to describe and evaluate the many branches in and through which it has unfolded itself. In reality the picture is not as dark as it may seem at first sight. Notwithstanding the obvious differences, most phenomenologists share certain insights that are very important for their mutual philosophical conception as a whole. In this connection the following must be mentioned: 1 Most phenomenologists admit a radical difference between the “natural” and the “philosophical” attitude. This leads necessarily to an equally radical difference between philosophy and science. In characterizing this difference some phenomenologists, in agreement with Husserl, stress only epistemological issues, whereas others, in agreement with Heidegger, focus their attention exclusively on ontological topics. 2 Notwithstanding this radical difference, there is a complicated set of relationships between philosophy and science. Within the context of these relationships philosophy has in some sense a foundational task with respect to the sciences, whereas science offers to philosophy at least a substantial part of its philosophical problematic. 3 To achieve its task philosophy must perform a certain reduction, or epoche, a radical change of attitude by which the philosopher turns from things to their meanings, from the ontic to the ontological, from the realm of the objectified meaning as found in the sciences to the realm of meaning as immediately experienced in the “life-world.” In other words, although it remains true that the various phenomenologists differ in characterizing the reduction, no one seriously doubts its necessity. 4 All phenomenologists subscribe to the doctrine of intentionality, though most elaborate this doctrine in their own way. For Husserl intentionality is a characteristic of conscious phenomena or acts; in a deeper sense, it is the characteristic of a finite consciousness that originally finds itself without a world. For Heidegger and most existentialists it is the human reality itself that is intentional; as Being-in-the-world its essence consists in its ek-sistence, i.e., in its standing out toward the world. 5 All phenomenologists agree on the fundamental idea that the basic concern of philosophy is to answer the question concerning the “meaning and Being” of beings. All agree in addition that in trying to materialize this goal the philosopher should be primarily interested not in the ultimate cause of all finite beings, but in how the Being of beings and the Being of the world are to be constituted. Finally, all agree that in answering the question concerning the meaning of Being a privileged position is to be attributed to subjectivity, i.e., to that being which questions the Being of beings. Phenomenologists differ, phenomenology phenomenology 665    665 however, the moment they have to specify what is meant by subjectivity. As noted above, whereas Husserl conceives it as a worldless monad, Heidegger and most later phenomenologists conceive it as being-in-the-world. Referring to Heidegger’s reinterpretation of his phenomenology, Husserl writes: one misinterprets my phenomenology backwards from a level which it was its very purpose to overcome, in other words, one has failed to understand the fundamental novelty of the phenomenological reduction and hence the progress from mundane subjectivity i.e., man to transcendental subjectivity; consequently one has remained stuck in an anthropology . . . which according to my doctrine has not yet reached the genuine philosophical level, and whose interpretation as philosophy means a lapse into “transcendental anthropologism,” that is, “psychologism.” 6 All phenomenologists defend a certain form of intuitionism and subscribe to what Husserl calls the “principle of all principles”: “whatever presents itself in ‘intuition’ in primordial form as it were in its bodily reality, is simply to be accepted as it gives itself out to be, though only within the limits in which it then presents itself.” Here again, however, each phenomenologist interprets this principle in keeping with his general conception of phenomenology as a whole. Thus, while phenomenologists do share certain insights, the development of the movement has nevertheless been such that it is not possible to give a simple definition of what phenomenology is. The fact remains that there are many phenomenologists and many phenomenologies. Therefore, one can only faithfully report what one has experienced of phenomenology by reading the phenomenologists. 

Philo Judaeus c.20 B.C.A.D. 40, Jewish Hellenistic philosopher of Alexandria who composed the bulk of his work in the form of commentaries and discourses on Scripture. He made the first known sustained attempt to synthesize its revealed teachings with the doctrines of classical philosophy. Although he was not the first to apply the methods of allegorical interpretation to Scripture, the number and variety of his interpretations make Philo unique. With this interpretive tool, he transformed biblical narratives into Platonic accounts of the soul’s quest for God and its struggle against passion, and the Mosaic commandments into specific manifestations of general laws of nature. Philo’s most influential idea was his conception of God, which combines the personal, ethical deity of the Bible with the abstract, transcendentalist theology of Platonism and Pythagoreanism. The Philonic deity is both the loving, just God of the Hebrew Patriarchs and the eternal One whose essence is absolutely unknowable and who creates the material world by will from primordial matter which He creates ex nihilo. Besides the intelligible realm of ideas, which Philo is the earliest known philosopher to identify as God’s thoughts, he posited an intermediate divine being which he called, adopting scriptural language, the logos. Although the exact nature of the logos is hard to pin down  Philo variously and, without any concern for consistency, called it the “first-begotten Son of the uncreated Father,” “Second God,” “idea of ideas,” “archetype of human reason,” and “pattern of creation”  its main functions are clear: to bridge the huge gulf between the transcendent deity and the lower world and to serve as the unifying law of the universe, the ground of its order and rationality. A philosophical eclectic, Philo was unknown to medieval Jewish philosophers but, beyond his anticipations of Neoplatonism, he had a lasting impact on Christianity through Clement of Alexandria, Origen, and Ambrose. 

Philolaus 470?390? B.C., pre-Socratic Grecian philosopher from Croton in southern Italy, the first Pythagorean to write a book. The surviving fragments of it are the earliest primary texts for Pythagoreanism, but numerous spurious fragments have also been preserved. Philolaus’s book begins with a cosmogony and includes astronomical, medical, and psychological doctrines. His major innovation was to argue that the cosmos and everything in it is a combination not just of unlimiteds what is structured and ordered, e.g. material elements but also of limiters structural and ordering elements, e.g. shapes. These elements are held together in a harmonia fitting together, which comes to be in accord with perspicuous mathematical relationships, such as the whole number ratios that correspond to the harmonic intervals e.g. octave % phenotext Philolaus 666    666 1 : 2. He argued that secure knowledge is possible insofar as we grasp the number in accordance with which things are put together. His astronomical system is famous as the first to make the earth a planet. Along with the sun, moon, fixed stars, five planets, and counter-earth thus making the perfect number ten, the earth circles the central fire a combination of the limiter “center” and the unlimited “fire”. Philolaus’s influence is seen in Plato’s Philebus; he is the primary source for Aristotle’s account of Pythagoreanism. 

philosophia perennis, a supposed body of truths that appear in the writings of the great philosophers, or the truths common to opposed philosophical viewpoints. The term is derived from the title of a book De perenni philosophia published by Agostino Steuco of Gubbio in 1540. It suggests that the differences between philosophers are inessential and superficial and that the common essential truth emerges, however partially, in the major philosophical schools. Aldous Huxley employed it as a title. L. Lavelle, N. Hartmann, and K. Jaspers also employ the phrase. M. De Wulf and many others use the phrase to characterize Neo-Thomism as the chosen vehicle of essential philosophical truths. R.M. philosophical anthropology, philosophical inquiry concerning human nature, often starting with the question of what generally characterizes human beings in contrast to other kinds of creatures and things. Thus broadly conceived, it is a kind of inquiry as old as philosophy itself, occupying philosophers from Socrates to Sartre; and it embraces philosophical psychology, the philosophy of mind, philosophy of action, and existentialism. Such inquiry presupposes no immutable “essence of man,” but only the meaningfulness of distinguishing between what is “human” and what is not, and the possibility that philosophy as well as other disciplines may contribute to our self-comprehension. It leaves open the question of whether other kinds of naturally occurring or artificially produced entity may possess the hallmarks of our humanity, and countenances the possibility of the biologically evolved, historically developed, and socially and individually variable character of everything about our attained humanity. More narrowly conceived, philosophical anthropology is a specific movement in recent European philosophy associated initially with Scheler and Helmuth Plessner, and subsequently with such figures as Arnold Gehlen, Cassirer, and the later Sartre. It initially emerged in the late 1920s in Germany, simultaneously with the existential philosophy of Heidegger and the critical social theory of the Frankfurt School, with which it competed as German philosophers turned their attention to the comprehension of human life. This movement was distinguished from the outset by its attempt to integrate the insights of phenomenological analysis with the perspectives attainable through attention to human and comparative biology, and subsequently to social inquiry as well. This turn to a more naturalistic approach to the understanding of ourselves, as a particular kind of living creature among others, is reflected in the titles of the two works published in 1928 that inaugurated the movement: Scheler’s Man’s Place in Nature and Plessner’s The Levels of the Organic and Man. For both Scheler and Plessner, however, as for those who followed them, our nature must be understood by taking further account of the social, cultural, and intellectual dimensions of human life. Even those like Gehlen, whose Der Mensch 1940 exhibits a strongly biological orientation, devoted much attention to these dimensions, which our biological nature both constrains and makes possible. For all of them, the relation between the biological and the social and cultural dimensions of human life is a central concern and a key to comprehending our human nature. One of the common themes of the later philosophical-anthropological literature  e.g., Cassirer’s An Essay on Man 1945 and Sartre’s Critique of Dialectical Reason 1960 as well as Plessner’s Contitio Humana 1965 and Gehlen’s Early Man and Late Culture 1963  is the plasticity of human nature, made possible by our biological constitution, and the resulting great differences in the ways human beings live. Yet this is not taken to preclude saying anything meaningful about human nature generally; rather, it merely requires attention to the kinds of general features involved and reflected in human diversity and variability. Critics of the very idea and possibility of a philosophical anthropology e.g., Althusser and Foucault typically either deny that there are any Philo of Larisa philosophical anthropology 667    667 such general features or maintain that there are none outside the province of the biological sciences to which philosophy can contribute nothing substantive. Both claims, however, are open to dispute; and the enterprise of a philosophical anthropology remains a viable and potentially significant one.

philosophy of biology, the philosophy of science applied to biology. On a conservative view of the philosophy of science, the same principles apply throughout science. Biology supplies additional examples but does not provide any special problems or require new principles. For example, the reduction of Mendelian genetics to molecular biology exemplifies the same sort of relation as the reduction of thermodynamics to statistical mechanics, and the same general analysis of reduction applies equally to both. More radical philosophers argue that the subject matter of biology has certain unique features; hence, the philosophy of biology is itself unique. The three features of biology most often cited by those who maintain that philosophy of biology is unique are functional organization, embryological development, and the nature of selection. Organisms are functionally organized. They are capable of maintaining their overall organization in the face of fairly extensive variation in their envisonments. Organisms also undergo ontogenetic development resulting from extremely complex interactions between the genetic makeup of the organism and its successive environments. At each step, the course that an organism takes is determined by an interplay between its genetic makeup, its current state of development, and the environment it happens to confront. The complexity of these interactions produces the naturenurture problem. Except for human artifacts, similar organization does not occur in the non-living world. The species problem is another classic issue in the philosophy of biology. Biological species have been a paradigm example of natural kinds since Aristotle. According to nearly all pre-Darwinian philosophers, species are part of the basic makeup of the universe, like gravity and gold. They were held to be as eternal, immutable, and discrete as these other examples of natural kinds. If Darwin was right, species are not eternal. They come and go, and once gone can no more reemerge than Aristotle can once again walk the streets of Athens. Nor are species immutable. A sample of lead can be transmuted into a sample of gold, but these elements as elements remain immutable in the face of such changes. However, Darwin insisted that species themselves, not merely their instances, evolved. Finally, because Darwin thought that species evolved gradually, the boundaries between species are not sharp, casting doubt on the essentialist doctrines so common in his day. In short, if species evolve, they have none of the traditional characteristics of species. Philosophers and biologists to this day are working out the consequences of this radical change in our worldview. The topic that has received the greatest attention by philosophers of biology in the recent literature is the nature of evolutionary theory, in particular selection, adaptation, fitness, and the population structure of species. In order for selection to operate, variation is necessary, successive generations must be organized genealogically, and individuals must interact differentially with their environments. In the simplest case, genes pass on their structure largely intact. In addition, they provide the information necessary to produce organisms. Certain of these organisms are better able to cope with their environments and reproduce than are other organisms. As a result, genes are perpetuated differentially through successive generations. Those characteristics that help an organism cope with its environments are termed adaptations. In a more restricted sense, only those characteristics that arose through past selective advantage count as adaptations. Just as the notion of IQ was devised as a single measure for a combination of the factors that influence our mental abilities, fitness is a measure of relative reproductive success. Claims about the tautological character of the principle philosophical behaviorism philosophy of biology of the survival of the fittest stem from the blunt assertion that fitness just is relative reproductive success, as if intelligence just is what IQ tests measure. Philosophers of biology have collaborated with biologists to analyze the notion of fitness. This literature has concentrated on the role that causation plays in selection and, hence, must play in any adequate explication of fitness. One important distinction that has emerged is between replication and differential interaction with the environment. Selection is a function of the interplay between these two processes. Because of the essential role of variation in selection, all the organisms that belong to the same species either at any one time or through time cannot possibly be essentially the same. Nor can species be treated adequately in terms of the statistical covariance of either characters or genes. The populational structure of species is crucial. For example, species that form numerous, partially isolated demes are much more likely to speciate than those that do not. One especially controversial question is whether species themselves can function in the evolutionary process rather than simply resulting from it. Although philosophers of biology have played an increasingly important role in biology itself, they have also addressed more traditional philosophical questions, especially in connection with evolutionary epistemology and ethics. Advocates of evolutionary epistemology argue that knowledge can be understood in terms of the adaptive character of accurate knowledge. Those organisms that hold false beliefs about their environment, including other organisms, are less likely to reproduce themselves than those with more accurate beliefs. To the extent that this argument has any force at all, it applies only to humansized entities and events. One common response to evolutionary epistemology is that sometimes people who hold manifestly false beliefs flourish at the expense of those who hold more realistic views of the world in which we live. On another version of evolutionary epistemology, knowledge acquisition is viewed as just one more instance of a selection process. The issue is not to justify our beliefs but to understand how they are generated and proliferated. Advocates of evolutionary ethics attempt to justify certain ethical principles in terms of their survival value. Any behavior that increases the likelihood of survival and reproduction is “good,” and anything that detracts from these ends is “bad.” The main objection to evolutionary ethics is that it violates the isought distinction. According to most ethical systems, we are asked to sacrifice ourselves for the good of others. If these others were limited to our biological relatives, then the biological notion of inclusive fitness might be adequate to account for such altruistic behavior, but the scope of ethical systems extends past one’s biological relatives. Advocates of evolutionary ethics are hard pressed to explain the full range of behavior that is traditionally considered as virtuous. Either biological evolution cannot provide an adequate justification for ethical behavior or else ethical systems must be drastically reduced in their scope.

philosophy of economics, the study of methodological issues facing positive economic theory and normative problems on the intersection of welfare economics and political philosophy. Methodological issues. Applying approaches and questions in the philosophy of science specifically to economics, the philosophy of economics explores epistemological and conceptual problems raised by the explanatory aims and strategy of economic theory: Do its assumptions about individual choice constitute laws, and do they explain its derived generalizations about markets and economies? Are these generalizations laws, and if so, how are they tested by observation of economic processes, and how are theories in the various compartments of economics  microeconomics, macroeconomics  related to one another and to econometrics? How are the various schools  neoclassical, institutional, Marxian, etc.  related to one another, and what sorts of tests might enable us to choose between their theories? Historically, the chief issue of interest in the development of the philosophy of economics has been the empirical adequacy of the assumptions of rational “economic man”: that all agents have complete and transitive cardinal or ordinal utility rankings or preference orders and that they always choose that available option which maximizes their utility or preferences. Since the actual behavior of agents appears to disconfirm these assumptions, the claim that they constitute causal laws governing economic behavior is difficult to sustain. On the other hand, the assumption of preference-maximizing behavior is indispensable to twentieth-century economics. These two considerations jointly undermine the claim that economic theory honors criteria on explanatory power and evidential probity drawn philosophy of economics philosophy of economics 669    669 from physical science. Much work by economists and philosophers has been devoted therefore to disputing the claim that the assumptions of rational choice theory are false or to disputing the inference from this claim to the conclusion that the cognitive status of economic theory as empirical science is thereby undermined. Most frequently it has been held that the assumptions of rational choice are as harmless and as indispensable as idealizations are elsewhere in science. This view must deal with the allegation that unlike theories embodying idealization elsewhere in science, economic theory gains little more in predictive power from these assumptions about agents’ calculations than it would secure without any assumptions about individual choice. Normative issues. Both economists and political philosophers are concerned with identifying principles that will ensure just, fair, or equitable distributions of scarce goods. For this reason neoclassical economic theory shares a history with utilitarianism in moral philosophy. Contemporary welfare economics continues to explore the limits of utilitarian prescriptions that optimal economic and political arrangements should maximize and/or equalize utility, welfare, or some surrogate. It also examines the adequacy of alternatives to such utilitarian principles. Thus, economics shares an agenda of interests with political and moral philosophy. Utilitarianism in economics and philosophy has been constrained by an early realization that utilities are neither cardinally measurable nor interpersonally comparable. Therefore the prescription to maximize and/or equalize utility cannot be determinatively obeyed. Welfare theorists have nevertheless attempted to establish principles that will enable us to determine the equity, fairness, or justice of various economic arrangements, and that do not rely on interpersonal comparisons required to measure whether a distribution is maximal or equal in the utility it accords all agents. Inspired by philosophers who have surrendered utilitarianism for other principles of equality, fairness, or justice in distribution, welfare economists have explored Kantian, social contractarian, and communitarian alternatives in a research program that cuts clearly across both disciplines. Political philosophy has also profited as much from innovations in economic theory as welfare economics has benefited from moral philosophy. Theorems from welfare economics that establish the efficiency of markets in securing distributions that meet minimal conditions of optimality and fairness have led moral philosophers to reexamine the moral status of free-market exchange. Moreover, philosophers have come to appreciate that coercive social institutions are sometimes best understood as devices for securing public goods  goods like police protection that cannot be provided to those who pay for them without also providing them to free riders who decline to do so. The recognition that everyone would be worse off, including free riders, were the coercion required to pay for these goods not imposed, is due to welfare economics and has led to a significant revival of interest in the work of Hobbes, who appears to have prefigured such arguments. 

philosophy of education, a branch of philosophy concerned with virtually every aspect of the educational enterprise. It significantly overlaps other, more mainstream branches especially epistemology and ethics, but even logic and metaphysics. The field might almost be construed as a “series of footnotes” to Plato’s Meno, wherein are raised such fundamental issues as whether virtue can be taught; what virtue is; what knowledge is; what the relation between knowledge of virtue and being virtuous is; what the relation between knowledge and teaching is; and how and whether teaching is possible. While few people would subscribe to Plato’s doctrine or convenient fiction, perhaps in Meno that learning by being taught is a process of recollection, the paradox of inquiry that prompts this doctrine is at once the root text of the perennial debate between rationalism and empiricism and a profoundly unsettling indication that teaching passeth understanding. Mainstream philosophical topics considered within an educational context tend to take on a decidedly genetic cast. So, e.g., epistemology, which analytic philosophy has tended to view as a justificatory enterprise, becomes concerned if not with the historical origins of knowledge claims then with their genesis within the mental economy of persons generally  in consequence of their educations. And even when philosophers of education come to endorse something akin to Plato’s classic account of knowledge as justified true belief, they are inclined to suggest, then, that the conveyance of knowledge via instruction must somehow provide the student with the justification along with the true philosophy of education philosophy of education 670    670 belief  thereby reintroducing a genetic dimension to a topic long lacking one. Perhaps, indeed, analytic philosophy’s general though not universal neglect of philosophy of education is traceable in some measure to the latter’s almost inevitably genetic perspective, which the former tended to decry as armchair science and as a threat to the autonomy and integrity of proper philosophical inquiry. If this has been a basis for neglect, then philosophy’s more recent, postanalytic turn toward naturalized inquiries that reject any dichotomy between empirical and philosophical investigations may make philosophy of education a more inviting area. Alfred North Whitehead, himself a leading light in the philosophy of education, once remarked that we are living in the period of educational thought subject to the influence of Dewey, and there is still no denying the observation. Dewey’s instrumentalism, his special brand of pragmatism, informs his extraordinarily comprehensive progressive philosophy of education; and he once went so far as to define all of philosophy as the general theory of education. He identifies the educative process with the growth of experience, with growing as developing  where experience is to be understood more in active terms, as involving doing things that change one’s objective environment and internal conditions, than in the passive terms, say, of Locke’s “impression” model of experience. Even traditionalistic philosophers of education, most notably Maritain, have acknowledged the wisdom of Deweyan educational means, and have, in the face of Dewey’s commanding philosophical presence, reframed the debate with progressivists as one about appropriate educational ends  thereby insufficiently acknowledging Dewey’s trenchant critique of the meansend distinction. And even some recent analytic philosophers of education, such as R. S. Peters, can be read as if translating Deweyan insights e.g., about the aim of education into an analytic idiom. Analytic philosophy of education, as charted by Peters, Israel Scheffler, and others in the Anglo-American philosophical tradition, has used the tools of linguistic analysis on a wide variety of educational concepts learning, teaching, training, conditioning, indoctrinating, etc. and investigated their interconnections: Does teaching entail learning? Does teaching inevitably involve indoctrinating? etc. This careful, subtle, and philosophically sophisticated work has made possible a much-needed conceptual precision in educational debates, though the debaters who most influence public opinion and policy have rarely availed themselves of that precisification. Recent work in philosophy of education, however, has taken up some major educational objectives  moral and other values, critical and creative thinking  in a way that promises to have an impact on the actual conduct of education. Philosophy of education, long isolated in schools of education from the rest of the academic philosophical community, has also been somewhat estranged from the professional educational mainstream. Dewey would surely have approved of a change in this status quo. 

philosophy of history, the philosophical study of human history and of attempts to record and interpret it. ‘History’ in English and its equivalent in most modern European languages has two primary senses: 1 the temporal progression of large-scale human events and actions, primarily but not exclusively in the past; and 2 the discipline or inquiry in which knowledge of the human past is acquired or sought. This has led to two senses of ‘philosophy of history’, depending on which “history” has been the object of philosophers’ attentions. Philosophy of history in the first sense is often called substantive or speculative, and placed under metaphysics. Philosophy of history in the second sense is called critical or analytic and can be placed in epistemology. Substantive philosophy of history. In the West, substantive philosophy of history is thought to begin only in the Christian era. In the City of God, Augustine wonders why Rome flourished while pagan, yet fell into disgrace after its conversion to Christiantity. Divine reward and punishment should apply to whole peoples, not just to individuals. The unfolding of events in history should exhibit a plan that is intelligible rationally, morally, and for Augustine theologically. As a believer Augustine is convinced that there is such a plan, though it may not always be evident. In the modern period, philosophers such as Vico and Herder also sought such intelligibility in history. They also believed in a long-term direction or purpose of history that is often opposed to and makes use of the purposes of individuals. The most elaborate and best-known example of this approach is found in Hegel, who thought that the gradual realization of human freedom could be discerned in history even if much slavery, tyranny, and suffering are necessary in the philosophy of history philosophy of history 671    671 process. Marx, too, claimed to know the laws  in his case economic  according to which history unfolds. Similar searches for overall “meaning” in human history have been undertaken in the twentieth century, notably by Arnold Toynbee 18891975, author of the twelve-volume Study of History, and Oswald Spengler 18801936, author of Decline of the West. But the whole enterprise was denounced by the positivists and neo-Kantians of the late nineteenth century as irresponsible metaphysical speculation. This attitude was shared by twentieth-century neopositivists and some of their heirs in the analytic tradition. There is some irony in this, since positivism, explicitly in thinkers like Comte and implicitly in others, involves belief in progressively enlightened stages of human history crowned by the modern age of science. Critical philosophy of history. The critical philosophy of history, i.e., the epistemology of historical knowledge, can be traced to the late nineteenth century and has been dominated by the paradigm of the natural sciences. Those in the positivist, neopositivist, and postpositivist tradition, in keeping with the idea of the unity of science, believe that to know the historical past is to explain events causally, and all causal explanation is ultimately of the same sort. To explain human events is to derive them from laws, which may be social, psychological, and perhaps ultimately biological and physical. Against this reductionism, the neo-Kantians and Dilthey argued that history, like other humanistic disciplines Geisteswissenschaften, follows irreducible rules of its own. It is concerned with particular events or developments for their own sake, not as instances of general laws, and its aim is to understand, rather than explain, human actions. This debate was resurrected in the twentieth century in the English-speaking world. Philosophers like Hempel and Morton White b.1917 elaborated on the notion of causal explanation in history, while Collingwood and William Dray b.1921 described the “understanding” of historical agents as grasping the thought behind an action or discovering its reasons rather than its causes. The comparison with natural science, and the debate between reductionists and antireductionists, dominated other questions as well: Can or should history be objective and valuefree, as science purportedly is? What is the significance of the fact that historians can never perceive the events that interest them, since they are in the past? Are they not limited by their point of view, their place in history, in a way scientists are not? Some positivists were inclined to exclude history from science, rather than make it into one, relegating it to “literature” because it could never meet the standards of objectivity and genuine explanation; it was often the anti-positivists who defended the cognitive legitimacy of our knowledge of the past. In the non-reductionist tradition, philosophers have increasingly stressed the narrative character of history: to understand human actions generally, and past actions in particular, is to tell a coherent story about them. History, according to W. B. Gallie b.1912, is a species of the genus Story. History does not thereby become fiction: narrative remains a “cognitive instrument” Louis Mink, 192183 just as appropriate to its domain as theory construction is to science. Nevertheless, concepts previously associated with fictional narratives, such as plot structure and beginning-middle-end, are seen as applying to historical narratives as well. This tradition is carried further by Hayden White b.1928, who analyzes classical nineteenth-century histories and even substantive philosophies of history such as Hegel’s as instances of romance, comedy, tragedy, and satire. In White’s work this mode of analysis leads him to some skepticism about history’s capacity to “represent” the reality of the past: narratives seem to be imposed upon the data, often for ideological reasons, rather than drawn from them. To some extent White’s view joins that of some positivists who believe that history’s literary character excludes it from the realm of science. But for White this is hardly a defect. Some philosophers have criticized the emphasis on narrative in discussions of history, since it neglects search and discovery, deciphering and evaluating sources, etc., which is more important to historians than the way they “write up” their results. Furthermore, not all history is presented in narrative form. The debate between pro- and anti-narrativists among philosophers of history has its parallel in a similar debate among historians themselves. Academic history in recent times has seen a strong turn away from traditional political history toward social, cultural, and economic analyses of the human past. Narrative is associated with the supposedly outmoded focus on the doings of kings, popes, and generals. These are considered e.g. by the French historian Fernand Braudel, 190285 merely surface ripples compared to the deeper-lying and slower-moving currents of social and economic change. It is the methods and concepts of the social sciences, not philosophy of history philosophy of history 672    672 the art of the storyteller, on which the historian must draw. This debate has now lost some of its steam and narrative history has made something of a comeback among historians. Among philosophers Paul Ricoeur has tried to show that even ostensibly non-narrative history retains narrative features. Historicity. Historicity or historicality: Geschichtlichkeit is a term used in the phenomenological and hermeneutic tradition from Dilthey and Husserl through Heidegger and Gadamer to indicate an essential feature of human existence. Persons are not merely in history; their past, including their social past, figures in their conception of themselves and their future possibilities. Some awareness of the past is thus constitutive of the self, prior to being formed into a cognitive discipine. Modernism and the postmodern. It is possible to view some of the debates over the modern and postmodern in recent Continental philosophy as a new kind of philosophy of history. Philosophers like Lyotard and Foucault see the modern as the period from the Enlightenment and Romanticism to the present, characterized chiefly by belief in “grand narratives” of historical progress, whether capitalist, Marxist, or positivist, with “man” as the triumphant hero of the story. Such belief is now being or should be abandoned, bringing modernism to an end. In one sense this is like earlier attacks on the substantive philosophy of history, since it unmasks as unjustified moralizing certain beliefs about large-scale patterns in history. It goes even further than the earlier attack, since it finds these beliefs at work even where they are not explicitly expressed. In another sense this is a continuation of the substantive philosophy of history, since it makes its own grand claims about largescale historical patterns. In this it joins hands with other philosophers of our day in a general historicization of knowledge e.g., the philosophy of science merges with the history of science and even of philosophy itself. Thus the later Heidegger  and more recently Richard Rorty  view philosophy itself as a large-scale episode in Western history that is nearing or has reached its end. Philosophy thus merges with the history of philosophy, but only thanks to a philosophical reflection on this history as part of history as a whole. 

philosophy of language, the philosophical study of natural language and its workings, particularly of linguistic meaning and the use of language. A natural language is any one of the thousands of various tongues that have developed historically among populations of human beings and have been used for everyday purposes  including English, Italian, Swahili, and Latin  as opposed to the formal and other artificial “languages” invented by mathematicians, logicians, and computer scientists, such as arithmetic, the predicate calculus, and LISP or COBOL. There are intermediate cases, e.g., Esperanto, Pig Latin, and the sort of “philosophese” that mixes English words with logical symbols. Contemporary philosophy of language centers on the theory of meaning, but also includes the theory of reference, the theory of truth, philosophical pragmatics, and the philosophy of linguistics. The main question addressed by the theory of meaning is: In virtue of what are certain physical marks or noises meaningful linguistic expressions, and in virtue of what does any particular set of marks or noises have the distinctive meaning it does? A theory of meaning should also give a comprehensive account of the “meaning phenomena,” or general semantic properties of sentences: synonymy, ambiguity, entailment, and the like. Some theorists have thought to express these questions and issues in terms of languageneutral items called propositions: ‘In virtue of what does a particular set of marks or noises express the proposition it does?’; cf. ‘ “La neige est blanche” expresses the proposition that snow is white’, and ‘Synonymous sentences express the same proposition’. On this view, to understand a sentence is to “grasp” the proposition expressed by that sentence. But the explanatory role and even the existence of such entities are disputed. It has often been maintained that certain special sentences are true solely in virtue of their meanings and/or the meanings of their component expressions, without regard to what the nonlinguistic world is like ‘No bachelor is married’; ‘If a thing is blue it is colored’. Such vacuously true sentences are called analytic. However, Quine and others have disputed whether there really is such a thing as analyticity. Philosophers have offered a number of sharply competing hypotheses as to the nature of meaning, including: 1 the referential view that words mean by standing for things, and that a sentence means what it does because its parts correspond referentially to the elements of an actual or possible state of affairs in the world; 2 ideational or mentalist theories, according to philosophy of language philosophy of language 673    673 which meanings are ideas or other psychological phenomena in people’s minds; 3 “use” theories, inspired by Wittgenstein and to a lesser extent by J. L. Austin: a linguistic expression’s “meaning” is its conventionally assigned role as a game-piece-like token used in one or more existing social practices; 4 H. P. Grice’s hypothesis that a sentence’s or word’s meaning is a function of what audience response a typical utterer would intend to elicit in uttering it. 5 inferential role theories, as developed by Wilfrid Sellars out of Carnap’s and Wittgenstein’s views: a sentence’s meaning is specified by the set of sentences from which it can correctly be inferred and the set of those which can be inferred from it Sellars himself provided for “language-entry” and “language-exit” moves as partly constitutive of meaning, in addition to inferences; 6 verificationism, the view that a sentence’s meaning is the set of possible experiences that would confirm it or provide evidence for its truth; 7 the truth-conditional theory: a sentence’s meaning is the distinctive condition under which it is true, the situation or state of affairs that, if it obtained, would make the sentence true; 8 the null hypothesis, or eliminativist view, that “meaning” is a myth and there is no such thing  a radical claim that can stem either from Quine’s doctrine of the indeterminacy of translation or from eliminative materialism in the philosophy of mind. Following the original work of Carnap, Alonzo Church, Hintikka, and Richard Montague in the 1950s, the theory of meaning has made increasing use of “possible worlds”based intensional logic as an analytical apparatus. Propositions sentence meanings considered as entities, and truth conditions as in 7 above, are now commonly taken to be structured sets of possible worlds  e.g., the set of worlds in which Aristotle’s maternal grandmother hates broccoli. And the structure imposed on such a set, corresponding to the intuitive constituent structure of a proposition as the concepts ‘grandmother’ and ‘hate’ are constituents of the foregoing proposition, accounts for the meaning-properties of sentences that express the proposition. Theories of meaning can also be called semantics, as in “Gricean semantics” or “Verificationist semantics,” though the term is sometimes restricted to referential and/or truth-conditional theories, which posit meaning-constitutive relations between words and the nonlinguistic world. Semantics is often contrasted with syntax, the structure of grammatically permissible ordering relations between words and other words in well-formed sentences, and with pragmatics, the rules governing the use of meaningful expressions in particular speech contexts; but linguists have found that semantic phenomena cannot be kept purely separate either from syntactic or from pragmatic phenomena. In a still more specialized usage, linguistic semantics is the detailed study typically within the truth-conditional format of particular types of construction in particular natural languages, e.g., belief-clauses in English or adverbial phrases in Kwakiutl. Linguistic semantics in that sense is practiced by some philosophers of language, by some linguists, and occasionally by both working together. Montague grammar and situation semantics are common formats for such work, both based on intensional logic. The theory of referenceis pursued whether or not one accepts either the referential or the truthconditional theory of meaning. Its main question is: In virtue of what does a linguistic expression designate one or more things in the world? Prior to theorizing and defining of technical uses, ‘designate’, ‘denote’, and ‘refer’ are used interchangeably. Denoting expressions are divided into singular terms, which purport to designate particular individual things, and general terms, which can apply to more than one thing at once. Singular terms include proper names ‘Cindy’, ‘Bangladesh’, definite descriptions ‘my brother’, ‘the first baby born in the New World’, and singular pronouns of various types ‘this’, ‘you’, ‘she’. General terms include common nouns ‘horse’, ‘trash can’, mass terms ‘water’, ‘graphite’, and plural pronouns ‘they’, ‘those’. The twentieth century’s dominant theory of reference has been the description theory, the view that linguistic terms refer by expressing descriptive features or properties, the referent being the item or items that in fact possess those properties. For example, a definite description does that directly: ‘My brother’ denotes whatever person does have the property of being my brother. According to the description theory of proper names, defended most articulately by Russell, such names express identifying properties indirectly by abbreviating definite descriptions. A general term such as ‘horse’ was thought of as expressing a cluster of properties distinctive of horses; and so forth. But the description theory came under heavy attack in the late 1960s, from Keith Donnellan, Kripke, and Putnam, and was generally abandoned on each of several grounds, in favor of the causal-historical theory of reference. The causal-historical idea is that a particular use of a linguistic expression denotes by being etiologically grounded in the thing or philosophy of language philosophy of language 674    674 group that is its referent; a historical causal chain of a certain shape leads backward in time from the act of referring to the referents. More recently, problems with the causal-historical theory as originally formulated have led researchers to backpedal somewhat and incorporate some features of the description theory. Other views of reference have been advocated as well, particularly analogues of some of the theories of meaning listed above  chiefly 26 and 8. Modal and propositional-attitude contexts create special problems in the theory of reference, for referring expressions seem to alter their normal semantic behavior when they occur within such contexts. Much ink has been spilled over the question of why and how the substitution of a term for another term having exactly the same referent can change the truth-value of a containing modal or propositional-attitude sentence. Interestingly, the theory of truth historically predates articulate study of meaning or of reference, for philosophers have always sought the nature of truth. It has often been thought that a sentence is true in virtue of expressing a true belief, truth being primarily a property of beliefs rather than of linguistic entities; but the main theories of truth have also been applied to sentences directly. The correspondence theory maintains that a sentence is true in virtue of its elements’ mirroring a fact or actual state of affairs. The coherence theory instead identifies truth as a relation of the true sentence to other sentences, usually an epistemic relation. Pragmatic theories have it that truth is a matter either of practical utility or of idealized epistemic warrant. Deflationary views, such as the traditional redundancy theory and D. Grover, J. Camp, and N. D. Belnap’s prosentential theory, deny that truth comes to anything more important or substantive than what is already codified in a recursive Tarskian truth-definition for a language. Pragmatics studies the use of language in context, and the context-dependence of various aspects of linguistic interpretation. First, one and the same sentence can express different meanings or propositions from context to context, owing to ambiguity or to indexicality or both. An ambiguous sentence has more than one meaning, either because one of its component words has more than one meaning as ‘bank’ has or because the sentence admits of more than one possible syntactic analysis ‘Visiting doctors can be tedious’, ‘The mouse tore up the street’. An indexical sentence can change in truth-value from context to context owing to the presence of an element whose reference fluctuates, such as a demonstrative pronoun ‘She told him off yesterday’, ‘It’s time for that meeting now’. One branch of pragmatics investigates how context determines a single propositional meaning for a sentence on a particular occasion of that sentence’s use. Speech act theory is a second branch of pragmatics that presumes the propositional or “locutionary” meanings of utterances and studies what J. L. Austin called the illocutionary forces of those utterances, the distinctive types of linguistic act that are performed by the speaker in making them. E.g., in uttering ‘I will be there tonight’, a speaker might be issuing a warning, uttering a threat, making a promise, or merely offering a prediction, depending on conventional and other social features of the situation. A crude test of illocutionary force is the “hereby” criterion: one’s utterance has the force of, say, a warning, if it could fairly have been paraphrased by the corresponding “explicitly performative” sentence beginning ‘I hereby warn you that . . .’..Speech act theory interacts to some extent with semantics, especially in the case of explicit performatives, and it has some fairly dramatic syntactic effects as well. A third branch of pragmatics not altogether separate from the second is the theory of conversation or theory of implicature, founded by H. P. Grice. Grice notes that sentences, when uttered in particular contexts, often generate “implications” that are not logical consequences of those sentences ‘Is Jones a good philosopher?’  ’He has very neat handwriting’. Such implications can usually be identified as what the speaker meant in uttering her sentence; thus for that reason and others, what Grice calls utterer’s meaning can diverge sharply from sentence-meaning or “timeless” meaning. To explain those non-logical implications, Grice offered a now widely accepted theory of conversational implicature. Conversational implicatures arise from the interaction of the sentence uttered with mutually shared background assumptions and certain principles of efficient and cooperative conversation. The philosophy of linguistics studies the academic discipline of linguistics, particularly theoretical linguistics considered as a science or purported science; it examines methodology and fundamental assumptions, and also tries to incorporate linguists’ findings into the rest of philosophy of language. Theoretical linguistics concentrates on syntax, and took its contempophilosophy of language philosophy of language 675    675 rary form in the 1950s under Zellig Harris and Chomsky: it seeks to describe each natural language in terms of a generative grammar for that language, i.e., a set of recursive rules for combining words that will generate all and only the “well-formed strings” or grammatical sentences of that language. The set must be finite and the rules recursive because, while our informationprocessing resources for recognizing grammatical strings as such are necessarily finite being subagencies of our brains, there is no limit in any natural language either to the length of a single grammatical sentence or to the number of grammatical sentences; a small device must have infinite generative and parsing capacity. Many grammars work by generating simple “deep structures” a kind of tree diagram, and then producing multiple “surface structures” as variants of those deep structures, by means of rules that rearrange their parts. The surface structures are syntactic parsings of natural-language sentences, and the deep structures from which they derive encode both basic grammatical relations between the sentences’ major constituents and, on some theories, the sentences’ main semantic properties as well; thus, sentences that share a deep structure will share some fundamental grammatical properties and all or most of their semantics. As Paul Ziff and Davidson saw in the 1960s, the foregoing syntactic problem and its solution had semantic analogues. From small resources, human speakers understand  compute the meanings of  arbitrarily long and novel sentences without limit, and almost instantaneously. This ability seems to require semantic compositionality, the thesis that the meaning of a sentence is a function of the meanings of its semantic primitives or smallest meaningful parts, built up by way of syntactic compounding. Compositionality also seems to be required by learnability, since a normal child can learn an infinitely complex dialect in at most two years, but must learn semantic primitives one at a time. A grammar for a natural language is commonly taken to be a piece of psychology, part of an explanation of speakers’ verbal abilities and behavior. As such, however, it is a considerable idealization: it is a theory of speakers’ linguistic “competence” rather than of their actual verbal performance. The latter distinction is required by the fact that speakers’ considered, reflective judgments of grammatical correctness do not line up very well with the class of expressions that actually are uttered and understood unreflectively by those same speakers. Some grammatical sentences are too hard for speakers to parse quickly; some are too long to finish parsing at all; speakers commonly utter what they know to be formally ungrammatical strings; and real speech is usually fragmentary, interspersed with vocalizations, false starts, and the like. Actual departures from formal grammaticality are ascribed by linguists to “performance limitations,” i.e., psychological factors such as memory failure, weak computational capacity, or heedlessness; thus, actual verbal behavior is to be explained as resulting from the perturbation of competence by performance limitations. 

philosophy of law, also called general jurisprudence, the study of conceptual and theoretical problems concerning the nature of law as such, or common to any legal system. Problems in the philosophy of law fall roughly into two groups. The first contains problems internal to law and legal systems as such. These include a the nature of legal rules; the conditions under which they can be said to exist and to influence practice; their normative character, as mandatory or advisory; and the indeterminacy of their language; b the structure and logical character of legal norms; the analysis of legal principles as a class of legal norms; and the relation between the normative force of law and coercion; c the identity conditions for legal systems; when a legal system exists; and when one legal system ends and another begins; d the nature of the reasoning used by courts in adjudicating cases; e the justification of legal decisions; whether legal justification is through a chain of inferences or by the coherence of norms and decisions; and the relation between intralegal and extralegal justification; f the nature of legal validity and of what makes a norm a valid law; the relation between validity and efficacy, the fact that the norms of a legal system are obeyed by the norm-subjects; g properties of legal systems, including comprehensiveness the claim to regulate any behavior and completeness the absence of gaps in the law; h legal rights; under what conditions citizens possess them; and their analytical structure as protected normative positions; i legal interpretation; whether it is a pervasive feature of law or is found only in certain kinds of adjudication; its rationality or otherwise; and its essentially ideological character or otherwise. The second group of problems concerns the philosophy of law philosophy of law 676    676 relation between law as one particular social institution in a society and the wider political and moral life of that society: a the nature of legal obligation; whether there is an obligation, prima facie or final, to obey the law as such; whether there is an obligation to obey the law only when certain standards are met, and if so, what those standards might be; b the authority of law; and the conditions under which a legal system has political or moral authority or legitimacy; c the functions of law; whether there are functions performed by a legal system in a society that are internal to the design of law; and analyses from the perspective of political morality of the functioning of legal systems; d the legal concept of responsibility; its analysis and its relation to moral and political concepts of responsibility; in particular, the place of mental elements and causal elements in the assignment of responsibility, and the analysis of those elements; e the analysis and justification of legal punishment; f legal liberty, and the proper limits or otherwise of the intrusion of the legal system into individual liberty; the plausibility of legal moralism; g the relation between law and justice, and the role of a legal system in the maintenance of social justice; h the relation between legal rights and political or moral rights; i the status of legal reasoning as a species of practical reasoning; and the relation between law and practical reason; j law and economics; whether legal decision making in fact tracks, or otherwise ought to track, economic efficiency; k legal systems as sources of and embodiments of political power; and law as essentially gendered, or imbued with race or class biases, or otherwise. Theoretical positions in the philosophy of law tend to group into three large kinds  legal positivism, natural law, and legal realism. Legal positivism concentrates on the first set of problems, and typically gives formal or content-independent solutions to such problems. For example, legal positivism tends to regard legal validity as a property of a legal rule that the rule derives merely from its formal relation to other legal rules; a morally iniquitous law is still for legal positivism a valid legal rule if it satisfies the required formal existence conditions. Legal rights exist as normative consequences of valid legal rules; no questions of the status of the right from the point of view of political morality arise. Legal positivism does not deny the importance of the second set of problems, but assigns the task of treating them to other disciplines  political philosophy, moral philosophy, sociology, psychology, and so forth. Questions of how society should design its legal institutions, for legal positivism, are not technically speaking problems in the philosophy of law, although many legal positivists have presented their theories about such questions. Natural law theory and legal realism, by contrast, regard the sharp distinction between the two kinds of problem as an artifact of legal positivism itself. Their answers to the first set of problems tend to be substantive or content-dependent. Natural law theory, for example, would regard the question of whether a law was consonant with practical reason, or whether a legal system was morally and politically legitimate, as in whole or in part determinative of the issue of legal validity, or of whether a legal norm granted a legal right. The theory would regard the relation between a legal system and liberty or justice as in whole or in part determinative of the normative force and the justification for that system and its laws. Legal realism, especially in its contemporary politicized form, sees the claimed role of the law in legitimizing certain gender, race, or class interests as the prime salient property of law for theoretical analysis, and questions of the determinacy of legal rules or of legal interpretation or legal right as of value only in the service of the project of explaining the political power of law and legal systems.

 philosophy of literature, literary theory. However, while the literary theorist, who is often a literary critic, is primarily interested in the conceptual foundations of practical criticism, philosophy of literature, usually done by philosophers, is more often concerned to place literature in the context of a philosophical system. Plato’s dialogues have much to say about poetry, mostly by way of aligning it with Plato’s metaphysical, epistemological, and ethico-political views. Aristotle’s Poetics, the earliest example of literary theory in the West, is also an attempt to accommodate the practice of Grecian poets to Aristotle’s philosophical system as a whole. Drawing on the thought of philosophers like Kant and Schelling, Samuel Taylor Coleridge offers in his Biographia philosophy of liberation philosophy of literature 677    677 Literaria a philosophy of literature that is to Romantic poetics what Aristotle’s treatise is to classical poetics: a literary theory that is confirmed both by the poets whose work it legitimates and by the metaphysics that recommends it. Many philosophers, among them Hume, Schopenhauer, Heidegger, and Sartre, have tried to make room for literature in their philosophical edifices. Some philosophers, e.g., the German Romantics, have made literature and the other arts the cornerstone of philosophy itself. See Philippe Lacoue-Labarthe and Jean-Luc Nancy, The Literary Absolute, 1988. Sometimes ‘philosophy of literature’ is understood in a second sense: philosophy and literature; i.e., philosophy and literature taken to be distinct and essentially autonomous activities that may nonetheless sustain determinate relations to each other. Philosophy of literature, understood in this way, is the attempt to identify the differentiae that distinguish philosophy from literature and to specify their relationships to each other. Sometimes the two are distinguished by their subject matter e.g., philosophy deals with objective structures, literature with subjectivity, sometimes by their methods philosophy is an act of reason, literature the product of imagination, inspiration, or the unconscious, sometimes by their effects philosophy produces knowledge, literature produces emotional fulfillment or release, etc. Their relationships then tend to occupy the areas in which they are not essentially distinct. If their subject matters are distinct, their effects may be the same philosophy and literature both produce understanding, the one of fact and the other of feeling; if their methods are distinct, they may be approaching the same subject matter in different ways; and so on. For Aquinas, e.g., philosophy and poetry may deal with the same objects, the one communicating truth about the object in syllogistic form, the other inspiring feelings about it through figurative language. For Heidegger, the philosopher investigates the meaning of being while the poet names the holy, but their preoccupations tend to converge at the deepest levels of thinking. For Sartre, literature is philosophy engagé, existential-political activity in the service of freedom. ’Philosophy of literature’ may also be taken in a third sense: philosophy in literature, the attempt to discover matters of philosophical interest and value in literary texts. The philosopher may undertake to identify, examine, and evaluate the philosophical content of literary texts that contain expressions of philosophical ideas and discussions of philosophical problems  e.g., the debates on free will and theodicy in Fyodor Dostoevsky’s The Brothers Karamazov. Many if not most  courses on philosophy of literature are taught from this point of view. Much interesting and important work has been done in this vein; e.g., Santayana’s Three Philosophical Poets 1910, Cavell’s essays on Emerson and Thoreau, and Nussbaum’s Love’s Knowledge 1989. It should be noted, however, that to approach the matter in this way presupposes that literature and philosophy are simply different forms of the same content: what philosophy expresses in the form of argument literature expresses in lyric, dramatic, or narrative form. The philosopher’s treatment of literature implies that he is uniquely positioned to explicate the subject matter treated in both literary and philosophical texts, and that the language of philosophy gives optimal expression to a content less adequately expressed in the language of literature. The model for this approach may well be Hegel’s Phenomenology of Spirit, which treats art along with religion as imperfect adumbrations of a truth that is fully and properly articulated only in the conceptual mode of philosophical dialectic. Dissatisfaction with this presupposition and its implicit privileging of philosophy over literature has led to a different view of the relation between philosophy and literature and so to a different program for philosophy of literature. The self-consciously literary form of Kierkegaard’s writing is an integral part of his polemic against the philosophical imperialism of the Hegelians. In this century, the work of philosophers like Derrida and the philosophers and critics who follow his lead suggests that it is mistaken to regard philosophy and literature as alternative expressions of an identical content, and seriously mistaken to think of philosophy as the master discourse, the “proper” expression of a content “improperly” expressed in literature. All texts, on this view, have a “literary” form, the texts of philosophers as well as the texts of novelists and poets, and their content is internally determined by their “means of expression.” There is just as much “literature in philosophy” as there is “philosophy in literature.” Consequently, the philosopher of literature may no longer be able simply to extract philosophical matter from literary form. Rather, the modes of literary expression confront the philosopher with problems that bear on the presuppositions of his own enterprise. E.g., fictional mimesis especially in the works of postmodern writers raises questions about the possibility and the prephilosophy of literature philosophy of literature 678    678 philosophy of logic philosophy of logic 679 sumed normativeness of factual representation, and in so doing tends to undermine the traditional hierarchy that elevates “fact” over “fiction.” Philosophers’ perplexity over the truth-value of fictional statements is an example of the kind of problems the study of literature can create for the practice of philosophy see Rorty, Consequences of Pragmatism, 1982, ch. 7. Or again, the self-reflexivity of contemporary literary texts can lead philosophers to reflect critically on their own undertaking and may seriously unsettle traditional notions of self-referentiality. When it is not regarded as another, attractive but perhaps inferior source of philosophical ideas, literature presents the philosopher with epistemological, metaphysical, and methodological problems not encountered in the course of “normal” philosophizing.

philosophy of logic, the arena of philosophy devoted to examining the scope and nature of logic. Aristotle considered logic an organon, or foundation, of knowledge. Certainly, inference is the source of much human knowledge. Logic judges inferences good or bad and tries to justify those that are good. One need not agree with Aristotle, therefore, to see logic as essential to epistemology. Philosophers such as Wittgenstein, additionally, have held that the structure of language reflects the structure of the world. Because inferences have elements that are themselves linguistic or are at least expressible in language, logic reveals general features of the structure of language. This makes it essential to linguistics, and, on a Wittgensteinian view, to metaphysics. Moreover, many philosophical battles have been fought with logical weaponry. For all these reasons, philosophers have tried to understand what logic is, what justifies it, and what it tells us about reason, language, and the world. The nature of logic. Logic might be defined as the science of inference; inference, in turn, as the drawing of a conclusion from premises. A simple argument is a sequence, one element of which, the conclusion, the others are thought to support. A complex argument is a series of simple arguments. Logic, then, is primarily concerned with arguments. Already, however, several questions arise. 1 Who thinks that the premises support the conclusion? The speaker? The audience? Any competent speaker of the language? 2 What are the elements of arguments? Thoughts? Propositions? Philosophers following Quine have found these answers unappealing for lack of clear identity criteria. Sentences are more concrete and more sharply individuated. But should we consider sentence tokens or sentence types? Context often affects interpretation, so it appears that we must consider tokens or types-in-context. Moreover, many sentences, even with contextual information supplied, are ambiguous. Is a sequence with an ambiguous sentence one argument which may be good on some readings and bad on others or several? For reasons that will become clear, the elements of arguments should be the primary bearers of truth and falsehood in one’s general theory of language. 3 Finally, and perhaps most importantly, what does ‘support’ mean? Logic evaluates inferences by distinguishing good from bad arguments. This raises issues about the status of logic, for many of its pronouncements are explicitly normative. The philosophy of logic thus includes problems of the nature and justification of norms akin to those arising in metaethics. The solutions, moreover, may vary with the logical system at hand. Some logicians attempt to characterize reasoning in natural language; others try to systematize reasoning in mathematics or other sciences. Still others try to devise an ideal system of reasoning that does not fully correspond to any of these. Logicians concerned with inference in natural, mathematical, or scientific languages tend to justify their norms by describing inferential practices in that language as actually used by those competent in it. These descriptions justify norms partly because the practices they describe include evaluations of inferences as well as inferences themselves. The scope of logic. Logical systems meant to account for natural language inference raise issues of the scope of logic. How does logic differ from semantics, the science of meaning in general? Logicians have often treated only inferences turning on certain commonly used words, such as ‘not’, ‘if’, ‘and’, ‘or’, ‘all’, and ‘some’, taking them, or items in a symbolic language that correspond to them, as logical constants. They have neglected inferences that do not turn on them, such as My brother is married. Therefore, I have a sister-in-law. Increasingly, however, semanticists have used ‘logic’ more broadly, speaking of the logic of belief, perception, abstraction, or even kinship.    679 philosophy of logic philosophy of logic 680 Such uses seem to treat logic and semantics as coextensive. Philosophers who have sought to maintain a distinction between the semantics and logic of natural language have tried to develop non-arbitrary criteria of logical constancy. An argument is valid provided the truth of its premises guarantees the truth of its conclusion. This definition relies on the notion of truth, which raises philosophical puzzles of its own. Furthermore, it is natural to ask what kind of connection must hold between the premises and conclusion. One answer specifies that an argument is valid provided replacing its simple constituents with items of similar categories while leaving logical constants intact could never produce true premises and a false conclusion. On this view, validity is a matter of form: an argument is valid if it instantiates a valid form. Logic thus becomes the theory of logical form. On another view, an argument is valid if its conclusion is true in every possible world or model in which its premises are true. This conception need not rely on the notion of a logical constant and so is compatible with the view that logic and semantics are coextensive. Many issues in the philosophy of logic arise from the plethora of systems logicians have devised. Some of these are deviant logics, i.e., logics that differ from classical or standard logic while seeming to treat the same subject matter. Intuitionistic logic, for example, which interprets the connectives and quantifiers non-classically, rejecting the law of excluded middle and the interdefinability of the quantifiers, has been supported with both semantic and ontological arguments. Brouwer, Heyting, and others have defended it as the proper logic of the infinite; Dummett has defended it as the correct logic of natural language. Free logic allows non-denoting referring expressions but interprets the quantifiers as ranging only over existing objects. Many-valued logics use at least three truthvalues, rejecting the classical assumption of bivalence  that every formula is either true or false. Many logical systems attempt to extend classical logic to incorporate tense, modality, abstraction, higher-order quantification, propositional quantification, complement constructions, or the truth predicate. These projects raise important philosophical questions. Modal and tense logics. Tense is a pervasive feature of natural language, and has become important to computer scientists interested in concurrent programs. Modalities of several sorts  alethic possibility, necessity and deontic obligation, permission, for example  appear in natural language in various grammatical guises. Provability, treated as a modality, allows for revealing formalizations of metamathematics. Logicians have usually treated modalities and tenses as sentential operators. C. I. Lewis and Langford pioneered such approaches for alethic modalities; von Wright, for deontic modalities; and Prior, for tense. In each area, many competing systems developed; by the late 1970s, there were over two hundred axiom systems in the literature for propositional alethic modal logic alone. How might competing systems be evaluated? Kripke’s semantics for modal logic has proved very helpful. Kripke semantics in effect treats modal operators as quantifiers over possible worlds. Necessarily A, e.g., is true at a world if and only if A is true in all worlds accessible from that world. Kripke showed that certain popular axiom systems result from imposing simple conditions on the accessibility relation. His work spawned a field, known as correspondence theory, devoted to studying the relations between modal axioms and conditions on models. It has helped philosophers and logicians to understand the issues at stake in choosing a modal logic and has raised the question of whether there is one true modal logic. Modal idioms may be ambiguous or indeterminate with respect to some properties of the accessibility relation. Possible worlds raise additional ontological and epistemological questions. Modalities and tenses seem to be linked in natural language, but attempts to bring tense and modal logic together remain young. The sensitivity of tense to intra- and extralinguistic context has cast doubt on the project of using operators to represent tenses. Kamp, e.g., has represented tense and aspect in terms of event structure, building on earlier work by Reichenbach. Truth. Tarski’s theory of truth shows that it is possible to define truth recursively for certain languages. Languages that can refer to their own sentences, however, permit no such definition given Tarski’s assumptions  for they allow the formulation of the liar and similar paradoxes. Tarski concluded that, in giving the semantics for such a language, we must ascend to a more powerful metalanguage. Kripke and others, however, have shown that it is possible for a language permitting self-reference to contain its own truth    680 predicate by surrendering bivalence or taking the truth predicate indexically. Higher-order logic. First-order predicate logic allows quantification only over individuals. Higher-order logics also permit quantification over predicate positions. Natural language seems to permit such quantification: ‘Mary has every quality that John admires’. Mathematics, moreover, may be expressed elegantly in higher-order logic. Peano arithmetic and Zermelo-Fraenkel set theory, e.g., require infinite axiom sets in firstorder logic but are finitely axiomatizable  and categorical, determining their models up to isomorphism  in second-order logic. Because they quantify over properties and relations, higher-order logics seem committed to Platonism. Mathematics reduces to higher-order logic; Quine concludes that the latter is not logic. Its most natural semantics seems to presuppose a prior understanding of properties and relations. Also, on this semantics, it differs greatly from first-order logic. Like set theory, it is incomplete; it is not compact. This raises questions about the boundaries of logic. Must logic be axiomatizable? Must it be possible, i.e., to develop a logical system powerful enough to prove every valid argument valid? Could there be valid arguments with infinitely many premises, any finite fragment of which would be invalid? With an operator for forming abstract terms from predicates, higher-order logics easily allow the formulation of paradoxes. Russell and Whitehead for this reason adopted type theory, which, like Tarski’s theory of truth, uses an infinite hierarchy and corresponding syntactic restrictions to avoid paradox. Type-free theories avoid both the restrictions and the paradoxes, as with truth, by rejecting bivalence or by understanding abstraction indexically. ,

philosophy of mathematics, the study of ontological and epistemological problems raised by the content and practice of mathematics. The present agenda in this field evolved from critical developments, notably the collapse of Pythagoreanism, the development of modern calculus, and an early twentieth-century foundational crisis, which forced mathematicians and philosophers to examine mathematical methods and presuppositions. Grecian mathematics. The Pythagoreans, who represented the height of early demonstrative Grecian mathematics, believed that all scientific relations were measureable by natural numbers 1, 2, 3, etc. or ratios of natural numbers, and thus they assumed discrete, atomic units for the measurement of space, time, and motion. The discovery of irrational magnitudes scotched the first of these beliefs. Zeno’s paradoxes showed that the second was incompatible with the natural assumption that space and time are infinitely divisible. The Grecian reaction, ultimately codified in Euclid’s Elements, included Plato’s separation of mathematics from empirical science and, within mathematics, distinguished number theory  a study of discretely ordered entities  from geometry, which concerns continua. Following Aristotle and employing methods perfected by Eudoxus, Euclid’s proofs used only “potentially infinite” geometric and arithmetic procedures. The Elements’ axiomatic form and its constructive proofs set a standard for future mathematics. Moreover, its dependence on visual intuition whose consequent deductive gaps were already noted by Archimedes, together with the challenge of Euclid’s infamous fifth postulate about parallel lines, and the famous unsolved problems of compass and straightedge construction, established an agenda for generations of mathematicians. The calculus. The two millennia following Euclid saw new analytical tools e.g., Descartes’s geometry that wedded arithmetic and geometric considerations and toyed with infinitesimally small quantities. These, together with the demands of physical application, tempted mathematicians to abandon the pristine Grecian dichotomies. Matters came to a head with Newton’s and Leibniz’s almost simultaneous discovery of the powerful computational techniques of the calculus. While these unified physical science in an unprecedented way, their dependence on unclear notions of infinitesimal spatial and temporal increments emphasized their shaky philosophical foundation. Berkeley, for instance, condemned the calculus for its unintuitability. However, this time the power of the new methods inspired a decidedly conservative response. Kant, in particular, tried to anchor the new mathematics in intuition. Mathematicians, he claimed, construct their objects in the “pure intuitions” of space and time. And these mathematical objects are the a priori forms of transcendentally ideal empirical objects. For Kant this combination of epistemic empiricism and ontological idealism explained the physical philosophy of mathematics philosophy of mathematics 681    681 applicability of mathematics and thus granted “objective validity” i.e., scientific legitimacy to mathematical procedures. Two nineteenth-century developments undercut this Kantian constructivism in favor of a more abstract conceptual picture of mathematics. First, Jànos Bolyai, Carl F. Gauss, Bernhard Riemann, Nikolai Lobachevsky, and others produced consistent non-Euclidean geometries, which undid the Kantian picture of a single a priori science of space, and once again opened a rift between pure mathematics and its physical applications. Second, Cantor and Dedekind defined the real numbers i.e., the elements of the continuum as infinite sets of rational and ultimately natural numbers. Thus they founded mathematics on the concepts of infinite set and natural number. Cantor’s set theory made the first concept rigorously mathematical; while Peano and Frege both of whom advocated securing rigor by using formal languages did that for the second. Peano axiomatized number theory, and Frege ontologically reduced the natural numbers to sets indeed sets that are the extensions of purely logical concepts. Frege’s Platonistic conception of numbers as unintuitable objects and his claim that mathematical truths follow analytically from purely logical definitions  the thesis of logicism  are both highly anti-Kantian. Foundational crisis and movements. But antiKantianism had its own problems. For one thing, Leopold Kronecker, who following Peter Dirichlet wanted mathematics reduced to arithmetic and no further, attacked Cantor’s abstract set theory on doctrinal grounds. Worse yet, the discovery of internal antinomies challenged the very consistency of abstract foundations. The most famous of these, Russell’s paradox the set of all sets that are not members of themselves both is and isn’t a member of itself, undermined Frege’s basic assumption that every well-formed concept has an extension. This was a full-scale crisis. To be sure, Russell himself together with Whitehead preserved the logicist foundational approach by organizing the universe of sets into a hierarchy of levels so that no set can be a member of itself. This is type theory. However, the crisis encouraged two explicitly Kantian foundational projects. The first, Hilbert’s Program, attempted to secure the “ideal” i.e., infinitary parts of mathematics by formalizing them and then proving the resultant formal systems to be conservative and hence consistent extensions of finitary theories. Since the proof itself was to use no reasoning more complicated than simple numerical calculations  finitary reasoning  the whole metamathematical project belonged to the untainted “contentual” part of mathematics. Finitary reasoning was supposed to update Kant’s intuition-based epistemology, and Hilbert’s consistency proofs mimic Kant’s notion of objective validity. The second project, Brouwer’s intuitionism, rejected formalization, and was not only epistemologically Kantian resting mathematical reasoning on the a priori intuition of time, but ontologically Kantian as well. For intuitionism generated both the natural and the real numbers by temporally ordered conscious acts. The reals, in particular, stem from choice sequences, which exploit Brouwer’s epistemic assumptions about the open future. These foundational movements ultimately failed. Type theory required ad hoc axioms to express the real numbers; Hilbert’s Program foundered on Gödel’s theorems; and intuitionism remained on the fringes because it rejected classical logic and standard mathematics. Nevertheless the legacy of these movements  their formal methods, indeed their philosophical agenda  still characterizes modern research on the ontology and epistemology of mathematics. Set theory, e.g. despite recent challenges from category theory, is the lingua franca of modern mathematics. And formal languages with their precise semantics are ubiquitous in technical and philosophical discussions. Indeed, even intuitionistic mathematics has been formalized, and Michael Dummett has recast its ontological idealism as a semantic antirealism that defines truth as warranted assertability. In a similar semantic vein, Paul Benacerraf proposed that the philosophical problem with Hilbert’s approach is inability to provide a uniform realistic i.e., referential, non-epistemic semantics for the allegedly ideal and contentual parts of mathematics; and the problem with Platonism is that its semantics makes its objects unknowable. Ontological issues. From this modern perspective, the simplest realism is the outright Platonism that attributes a standard model consisting of “independent” objects to classical theories expressed in a first-order language i.e., a language whose quantifiers range over objects but not properties. But in fact realism admits variations on each aspect. For one thing, the Löwenheim-Skolem theorem shows that formalized theories can have non-standard models. There are expansive non-standard models: Abraham Robinson, e.g., used infinitary non-stanphilosophy of mathematics philosophy of mathematics 682    682 dard models of Peano’s axioms to rigorously reintroduce infinitesimals. Roughly, an infinitesimal is the reciprocal of an infinite element in such a model. And there are also “constructive” models, whose objects must be explicitly definable. Predicative theories inspired by Poincaré and Hermann Weyl, whose stage-by-stage definitions refer only to previously defined objects, produce one variety of such models. Gödel’s constructive universe, which uses less restricted definitions to model apparently non-constructive axioms like the axiom of choice, exemplifies another variety. But there are also views various forms of structuralism which deny that formal theories have unique standard models at all. These views  inspired by the fact, already sensed by Dedekind, that there are multiple equivalid realizations of formal arithmetic  allow a mathematical theory to characterize only a broad family of models and deny unique reference to mathematical terms. Finally, some realistic approaches advocate formalization in secondorder languages, and some eschew ordinary semantics altogether in favor of substitutional quantification. These latter are still realistic, for they still distinguish truth from knowledge. Strict finitists  inspired by Wittgenstein’s more stringent epistemic constraints  reject even the open-futured objects admitted by Brouwer, and countenance only finite or even only “feasible” objects. In the other direction, A. A. Markov and his school in Russia introduced a syntactic notion of algorithm from which they developed the field of “constructive analysis.” And the American mathematician Errett Bishop, starting from a Brouwer-like disenchantment with mathematical realism and with strictly formal approaches, recovered large parts of classical analysis within a non-formal constructive framework. All of these approaches assume abstract i.e., causally isolated mathematical objects, and thus they have difficulty explaining the wide applicability of mathematics constructive or otherwise within empirical science. One response, Quine’s “indispensability” view, integrates mathematical theories into the general network of empirical science. For Quine, mathematical objects  just like ordinary physical objects  exist simply in virtue of being referents for terms in our best scientific theory. By contrast Hartry Field, who denies that any abstract objects exist, also denies that any purely mathematical assertions are literally true. Field attempts to recast physical science in a relational language without mathematical terms and then use Hilbert-style conservative extension results to explain the evident utility of abstract mathematics. Hilary Putnam and Charles Parsons have each suggested views according to which mathematics has no objects proper to itself, but rather concerns only the possibilities of physical constructions. Recently, Geoffrey Hellman has combined this modal approach with structuralism. Epistemological issues. The equivalence proved in the 1930s of several different representations of computability to the reasoning representable in elementary formalized arithmetic led Alonzo Church to suggest that the notion of finitary reasoning had been precisely defined. Church’s thesis so named by Stephen Kleene inspired Georg Kreisel’s investigations in the 1960s and 70s of the general conditions for rigorously analyzing other informal philosophical notions like semantic consequence, Brouwerian choice sequences, and the very notion of a set. Solomon Feferman has suggested more recently that this sort of piecemeal conceptual analysis is already present in mathematics; and that this rather than any global foundation is the true role of foundational research. In this spirit, the relative consistency arguments of modern proof theory a continuation of Hilbert’s Program provide information about the epistemic grounds of various mathematical theories. Thus, on the one hand, proofs that a seemingly problematic mathematical theory is a conservative extension of a more secure theory provide some epistemic support for the former. In the other direction, the fact that classical number theory is consistent relative to intuitionistic number theory shows contra Hilbert that his view of constructive reasoning must differ from that of the intuitionists. Gödel, who did not believe that mathematics required any ties to empirical perception, suggested nevertheless that we have a special nonsensory faculty of mathematical intuition that, when properly cultivated, can help us decide among formally independent propositions of set theory and other branches of mathematics. Charles Parsons, in contrast, has examined the place of perception-like intuition in mathematical reasoning. Parsons himself has investigated models of arithmetic and of set theory composed of quasi-concrete objects e.g., numerals and other signs. Others consistent with some of Parsons’s observations have given a Husserlstyle phenomenological analysis of mathematical intuition. Frege’s influence encouraged the logical positivists and other philosophers to view mathematical knowledge as analytic or conventional. philosophy of mathematics philosophy of mathematics 683    683 Poincaré responded that the principle of mathematical induction could not be analytic, and Wittgenstein also attacked this conventionalism. In recent years, various formal independence results and Quine’s attack on analyticity have encouraged philosophers and historians of mathematics to focus on cases of mathematical knowledge that do not stem from conceptual analysis or strict formal provability. Some writers notably Mark Steiner and Philip Kitcher emphasize the analogies between empirical and mathematical discovery. They stress such things as conceptual evolution in mathematics and instances of mathematical generalizations supported by individual cases. Kitcher, in particular, discusses the analogy between axiomatization in mathematics and theoretical unification. Penelope Maddy has investigated the intramathematical grounds underlying the acceptance of various axioms of set theory. More generally, Imre Lakatos argued that most mathematical progress stems from a concept-stretching process of conjecture, refutation, and proof. This view has spawned a historical debate about whether critical developments such as those mentioned above represent Kuhn-style revolutions or even crises, or whether they are natural conceptual advances in a uniformly growing science. 

philosophy of mind, the branch of philosophy that includes the philosophy of psychology, philosophical psychology, and the area of metaphysics concerned with the nature of mental phenomena and how they fit into the causal structure of reality. Philosophy of psychology, a branch of the philosophy of science, examines what psychology says about the nature of psychological phenomena; examines aspects of psychological theorizing such as the models used, explanations offered, and laws invoked; and examines how psychology fits with the social sciences and natural sciences. Philosophical psychology investigates folk psychology, a body of commonsensical, protoscientific views about mental phenomena. Such investigations attempt to articulate and refine views found in folk psychology about conceptualization, memory, perception, sensation, consciousness, belief, desire, intention, reasoning, action, and so on. The mindbody problem, a central metaphysical one in the philosophy of mind, is the problem of whether mental phenomena are physical and, if not, how they are related to physical phenomena. Other metaphysical problems in the philosophy of mind include the free will problem, the problem of personal identity, and the problem of how, if at all, irrational phenomena such as akrasia and self-deception are possible. Mindbody dualism Cartesian dualism. The doctrine that the soul is distinct from the body is found in Plato and discussed throughout the history of philosophy, but Descartes is considered the father of the modern mindbody problem. He maintained that the essence of the physical is extension in space. Minds are unextended substances and thus are distinct from any physical substances. The essence of a mental substance is to think. This twofold view is called Cartesian dualism. Descartes was well aware of an intimate relationship between mind and the brain. There is no a priori reason to think that the mind is intimately related to the brain; Aristotle, e.g., did not associate them. Descartes mistakenly thought the seat of the relationship was in the pineal gland. He maintained, however, that our minds are not our brains, lack spatial location, and can continue to exist after the death and destruction of our bodies. Cartesian dualism invites the question: What connects the mind and brain? Causation is Descartes’s answer: states of our minds causally interact with states of our brains. When bodily sensations such as aches, pains, itches, and tickles cause us to moan, wince, scratch, or laugh, they do so by causing brain states events, processes, which in turn cause bodily movements. In deliberate action, we act on our desires, motives, and intentions to carry out our purposes; and acting on these mental states involves their causing brain states, which in turn cause our bodies to move, thereby causally influencing the physical world. The physical world, in turn, influences our minds through its influence on our brains. Perception of the physical world with five senses  sight, hearing, smell, taste, and touch  involves causal transactions from the physical to the mental: what we perceive i.e., see, hear, etc. causes a sense experience i.e., a visual experience, aural experience, etc.. Thus, Descartes held that there is two-way psychophysical causal interaction: from the mental to the physical as in action and from the physical to the mental as in perception. The conjunction of Cartesian dualism and the doctrine of two-way psychophysical causal interaction is called Cartesian interactionism. philosophy of mind philosophy of mind 684    684 Perhaps the most widely discussed difficulty for this view is how states of a non-spatial substance a mind can causally interact with states of a substance that is in space a brain. Such interactions have seemed utterly mysterious to many philosophers. Mystery would remain even if an unextended mind is locatable at a point in space say, the center of the pineal gland. For Cartesian interactionism would still have to maintain that causal transactions between mental states and brain states are fundamental, i.e., unmediated by any underlying mechanism. Brain states causally interact with mental states, but there is no answer to the question of how they do so. The interactions are brute facts. Many philosophers, including many of Descartes’s contemporaries, have found that difficult to accept. Parallelism. Malebranche and Leibniz, among others, rejected the possibility of psychophysical causal interaction. They espoused versions of parallelism: the view that the mental and physical realms run in parallel, in that types of mental phenomena co-occur with certain types of physical phenomena, but these co-occurrences never involve causal interactions. On all extant versions, the parallels hold because of God’s creation. Leibniz’s parallelism is preestablished harmony: the explanation of why mental types and certain physical types co-occur is that in the possible world God actualized i.e., this world they co-occur. In discussing the relation between the mental and physical realms, Leibniz used the analogy of two synchronized but unconnected clocks. The analogy is, however, somewhat misleading; suggesting causal mechanisms internal to each clock and intramental and intraphysical causal transactions. But Leibniz’s monadology doctrine excludes the possibility of such transactions: mental and physical phenomena have no effects even within their own realms. Malebranche is associated with occasionalism, according to which only God, through his continuous activities, causes things to happen: non-divine phenomena never cause anything. Occasionalism differs from preestablished harmony in holding that God is continually engaged in acts of creation; each moment creating the world anew, in such a way that the correlations hold. Both brands of parallelism face formidable difficulties. First, both rest on highly contentious, obscure theological hypotheses. The contention that God exists and the creation stories in question require extensive defense and explanation. God’s relationship to the world can seem at least as mysterious as the relationship Descartes posits between minds and brains. Second, since parallelism denies the possibility of psychophysical interaction, its proponents must offer alternatives to the causal theory of perception and the causal theory of action or else deny that we can perceive and that we can act intentionally. Third, since parallelism rejects intramental causation, it must either deny that reasoning is possible or explain how it is possible without causal connections between thoughts. Fourth, since parallelism rejects physical transactions, it is hard to see how it can allow, e.g., that one physical thing ever moves another; for that would require causing a change in location. Perhaps none of these weighty difficulties is ultimately insuperable; in any case, parallelism has been abandoned. Epiphenomenalism. Empirical research gives every indication that the occurrence of any brain state can, in principle, be causally explained by appeal solely to other physical states. To accommodate this, some philosophers espoused epiphenomenalism, the doctrine that physical states cause mental states, but mental states do not cause anything. This thesis was discussed under the name ‘conscious automatism’ by Huxley and Hogeson in the late nineteenth century. William James was the first to use the term ‘epiphenomena’ to mean phenomena that lack causal efficacy. And James Ward coined the term ‘epiphenomenalism’ in 1903. Epiphenomenalism implies that there is only one-way psychophysical action  from the physical to the mental. Since epiphenomenalism allows such causal action, it can embrace the causal theory of perception. However, when combined with Cartesian dualism, epiphenomenalism, like Cartesian interactionism, implies the problematic thesis that states of an extended substance can affect states of an unextended substance. An epiphenomenalist can avoid this problem by rejecting the view that the mind is an unextended substance while maintaining that mental states and events are nonetheless distinct from physical states and events. Still, formidable problems would remain. It is hard to see how epiphenomenalism can allow that we are ever intentional agents. For intentional agency requires acting on reasons, which, according to the causal theory of action, requires a causal connection between reasons and actions. Since epiphenomenalism denies that such causal connections are possible, it must either maintain that our sense of agency is illusory or offer an alternative to the causal theory of action. Similarly, it must explain how thinking is possible philosophy of mind philosophy of mind 685    685 given that there are no causal connections between thoughts. Monism The dual-aspect theory. Many philosophers reject Descartes’s bifurcation of reality into mental and physical substances. Spinoza held a dualattribute theory  also called the dual-aspect theory  according to which the mental and the physical are distinct modes of a single substance, God. The mental and the physical are only two of infinitely many modes of this one substance. Many philosophers opted for a thoroughgoing monism, according to which all of reality is really of one kind. Materialism, idealism, and neutral monism are three brands of monism. Hobbes, a contemporary of Descartes, espoused materialism, the brand of monism according to which everything is material or physical. Berkeley is associated with idealism, the brand of monism according to which everything is mental. He held that both mental and physical phenomena are perceptions in the mind of God. For Hegel’s idealism, everything is part of the World Spirit. The early twentieth-century British philosophers Bradley and McTaggart also held a version of idealism. Neutral monism is the doctrine that all of reality is ultimately of one kind, which is neither mental nor physical. Hume was a neutral monist, maintaining that mental and physical substances are really just bundles of the neutral entities. Versions of neutral monism were later held by Mach and, for a short time, Russell. Russell called his neutral entities sensibilia and claimed that minds and physical objects are logical constructions out of them. Phenomenalism. This view, espoused in the twentieth century by, among others, Ayer, argues that all empirical statements are synonymous with statements solely about phenomenal appearances. While the doctrine is about statements, phenomenalism is either a neutral monism or an idealism, depending on whether phenomenal appearances are claimed to be neither mental nor physical or, instead, mental. The required translations of physical statements into phenomenal ones proved not to be forthcoming, however. Chisholm offered a reason why they would not be: what appearances a physical state of affairs e.g., objects arrayed in a room has depends both on physical conditions of observation e.g., lighting and physical conditions of the perceiver e.g., of the nervous system. At best, a statement solely about phenomenal appearances is equivalent to one about a physical state of affairs, only when certain physical conditions of observation and certain physical conditions of the perceiver obtain. Materialism. Two problems face any monism: it must characterize the phenomena it takes as basic, and it must explain how the fundamental phenomena make up non-basic phenomena. The idealist and neutral monist theories proposed thus far have faltered on one or both counts. Largely because of scientific successes of the twentieth century, such as the rebirth of the atomic theory of matter, and the successes of quantum mechanics in explaining chemistry and of chemistry in turn in explaining much of biology, many philosophers today hold that materialism will ultimately succeed where idealism and neutral monism apparently failed. Materialism, however, comes in many different varieties and each faces formidable difficulties. Logical behaviorism. Ryle ridiculed Cartesianism as the view that there is a ghost in the machine the body. He claimed that the view that the mind is a substance rests on a category mistake: ‘mind’ is a noun, but does not name an object. Cartesianism confuses the logic of discourse about minds with the logic of discourse about bodies. To have a mind is not to possess a special sort of entity; it is simply to have certain capacities and dispositions. Compare the thesis that to be alive is to possess not a certain entity, an entelechy or élan vital, but rather certain capacities and dispositions. Ryle maintained, moreover, that it was a mistake to regard mental states such as belief, desire, and intention as internal causes of behavior. These states, he claimed, are dispositions to behave in overt ways. In part in response to the dualist point that one can understand our ordinary psychological vocabulary ‘belief’, ‘desire’, ‘pain’, etc. and know nothing about the physical states and events in the brain, logical behaviorism has been proposed as a materialist doctrine that explains this fact. On this view, talk of mental phenomena is shorthand for talk of actual and potential overt bodily behavior i.e., dispositions to overt bodily behavior. Logical behaviorism was much discussed from roughly the 1930s until the early 1960s. While Ryle is sometimes counted as a logical behaviorist, he was not committed to the thesis that all mental talk can be translated into behavioral talk. The translations promised by logical behaviorism appear unachievable. As Putnam and others pointed out, one can fake being in pain and one can be in pain and yet not behave or be disposed to behave as if one were in pain e.g., one might philosophy of mind philosophy of mind 686    686 be paralyzed or might be a “super-spartan”. Logical behaviorism faces similar difficulties in translating sentences about what Russell called propositional attitudes i.e., beliefs that p, desires that p, hopes that p, intentions that p, and the like. Consider the following sample proposal similar to one offered by Carnap: one believes that the cat is on the mat if and only if one is disposed to assent to ‘The cat is on the mat’. First, the proposed translation meets the condition of being purely behavioral only if assenting is understandable in purely behavioral terms. That is doubtful. The proposal also fails to provide a sufficient or a necessary condition: someone may assent to ‘The cat is on the mat’ and yet not believe the cat is on the mat for the person may be trying to deceive; and a belief that the cat is on the mat will dispose one to assent to ‘The cat is on the mat’ only if one understands what is being asked, wants to indicate that one believes the cat is on the mat, and so on. But none of these conditions is required for believing that the cat is on the mat. Moreover, to invoke any of these mentalistic conditions defeats the attempt to provide a purely behavioral translation of the belief sentence. Although the project of translation has been abandoned, in recent years Dennett has defended a view in the spirit of logical behaviorism, intentional systems theory: belief-desire talk functions to characterize overall patterns of dispositions to overt behavior in an environmental context for the purposes of predicting overt behavior. The theory is sometimes characterized as supervenient behaviorism since it implies that whether an individual has beliefs, desires, intentions and the like supervenes on his dispositions to overt behavior: if two individuals are exactly alike in respect of their dispositions to overt behavior, the one has intentional states if and only if the other does. This view allows, however, that the contents of an individual’s intentional states  what the individual believes, desires, etc.  may depend on environmental factors. So it is not committed to the supervenience of the contents of intentional states on dispositions to overt behavior.the discussion of content externalism below. One objection to this view, due to Ned Block, is that it would mistakenly count as an intentional agent a giant look-up table  “a Blockhead”  that has the same dispositions to peripheral behavior as a genuine intentional agent. A look-up table is a simple mechanical device that looks up preprogrammed responses. Identity theories. In the early 1950s, Herbert Feigl claimed that mental states are brain states. He pointed out that if mental properties or state types are merely nomologically correlated with physical properties or state types, the connecting laws would be “nomological danglers”: irreducible to physical laws, and thus additional fundamental laws. According to the identity theory, the connecting laws are not fundamental laws and so not nomological danglers since they can be explained by identifying the mental and physical properties in question. In the late 1950s and the early 1960s, the philosopher Smart and the psychologist U. T. Place defended the materialist view that sensations are identical with brain processes. Smart claimed that while mental terms differ in meaning from physical terms, scientific investigation reveals that they have the same referents as certain physical terms. Compare the fact that while ‘the Morning Star’ and ‘the Evening Star’ differ in meaning empirical investigation reveals the same referent: Venus. Smart and Place claimed that feeling pain, e.g., is some brain process, exactly which one to be determined by scientific investigation. Smart claimed that sensation talk is paraphraseable in topic-neutral terms; i.e., in terms that leave open whether sensational properties are mental or physical. ‘I have an orange afterimage’ is paraphraseable roughly as: ‘There is something going on like what is going on when I have my eyes open, am awake, and there is an orange illuminated in good light in front of me, i.e., when I really see an orange’. The description is topic-neutral since it leaves open whether what is going on is mental or physical. Smart maintained that scientific investigation reveals that what in fact meets the topic-neutral description is a brain process. He held that psychophysical identity statements such as ‘Pain is C-fiber firing’ are contingent, likening these to, e.g., ‘Lightning is electrical discharge’, which is contingent and knowable only through empirical investigation. Central state materialism. This brand of materialism was defended in the late 1960s and the early 1970s by Armstrong and others. On this view, mental states are states that are apt to produce a certain range of behavior. Central state materialists maintain that scientific investigation reveals that such states are states of the central nervous system, and thus that mental states are contingently identical with states of the central nervous system. Unlike logical behaviorism, central state materialism does not imply that mental sentences can be translated into physical sentences. Unlike both logical behaviorism and philosophy of mind philosophy of mind 687    687 intentional systems theory, central state materialism implies that mental states are actual internal states with causal effects. And unlike Cartesian interactionism, it holds that psychophysical interaction is just physical causal interaction. Some central state materialists held in addition that the mind is the brain. However, if the mind were the brain, every change in the brain would be a change in the mind; and that seems false: not every little brain change amounts to a change of mind. Indeed, the mind ceases to exist when brain death occurs, while the brain continues to exist. The moral that most materialists nowadays draw from such considerations is that the mind is not any physical substance, since it is not a substance of any sort. To have a mind is not to possess a special substance, but rather to have certain capacities  to think, feel, etc. To that extent, Ryle was right. However, central state materialists insist that the properly functioning brain is the material seat of mental capacities, that the exercise of mental capacities consists of brain processes, and that mental states are brain states that can produce behavior. Epistemological objections have been raised to identity theories. As self-conscious beings, we have a kind of privileged access to our own mental states. The exact avenue of privileged access, whether it is introspection or not, is controversial. But it has seemed to many philosophers that our access to our own mental states is privileged in being open only to us, whereas we lack any privileged access to the states of our central nervous systems. We come to know about central nervous system states in the same way we come to know about the central nervous system states of others. So, against central state materialism and the identity theory, it is claimed that mental states cannot be states of our central nervous systems. Taking privileged access to imply that we have incorrigible knowledge of our conscious mental states, and despairing of squaring privileged access so understood with materialism, Rorty advocated eliminative materialism, the thesis that there actually are no mental phenomena. A more common materialist response, however, is to deny that privileged access entails incorrigibility and to maintain that privileged access is compatible with materialism. Some materialists maintain that while certain types of mental states e.g., sensations are types of neurological states, it will be knowable only by empirical investigation that they are. Suppose pain is a neural state N. It will be only a posteriori knowable that pain is N. Via the avenue of privileged access, one comes to believe that one is in a pain state, but not that one is in an N-state. One can believe one is in a pain state without believing that one is in an N-state because the concept of pain is different from the concept of N. Nevertheless, pain is N. Compare the fact that while water is H2O, the concept of water is different from that of H2O. Thus, while water is H2O, one can believe there is water in the glass without believing that there is H2O in it. The avenue of privileged access presents N conceptualized as pain, but never as neurological state N. The avenue of privileged access involves the exercise of mental, but not neurophysiological, concepts. However, our mental concepts answer to  apply in virtue of  the same properties state types as do certain of our neurophysiological concepts. The identity theory and central state materialism both hold that there are contingent psychophysical property and type identities. Some theorists in this tradition tried to distinguish a notion of theoretical identity from the notion of strict identity. They held that mental states are theoretically, but not strictly, identical with brain states. Against any such distinction, Kripke argued that identities are metaphysically necessary, i.e., hold in every possible world. If A % B, then necessarily A % B. Kripke acknowledged that there can be contingent statements of identity. But such statements, he argued, will employ at least one term that is not a rigid designator, i.e., a term that designates the same thing in every world in which it designates anything. Thus, since ‘the inventor of bifocals’ is a non-rigid designator, ‘Benjamin Franklin is the inventor of bifocals’ is contingent. While Franklin is the inventor of bifocals, he might not have been. However, statements of identity in which the identity sign is flanked by rigid designators are, if true, metaphysically necessary. Kripke held that proper names are rigid designators, and hence, the true identity statement ‘Cicero is Tully’ is metaphysically necessary. Nonetheless, a metaphysically necessary identity statement can be knowable only a posteriori. Indeed, ‘Cicero is Tully’ is knowable only a posteriori. Both ‘water’ and ‘H2O’, he maintained, are rigid designators: each designates the same kind of stuff in every possible world. And he thus maintained that it is metaphysically necessary that water is H2O, despite its not being a priori knowable that water is H2O. On Kripke’s view, any psychophysical identity statement that employs mental terms and physical terms that are rigid designators will also be metaphysically necessary, if true. philosophy of mind philosophy of mind 688    688 Central state materialists maintain that mental concepts are equivalent to concepts whose descriptive content is the state that is apt to produce such-and-such behavior in such-and-such circumstances. These defining descriptions for mental concepts are intended to be meaning-giving, not contingent reference-fixing descriptions; they are, moreover, not rigid designators. Thus, the central state materialists can concede that all identities are necessary, but maintain that psychophysical claims of identity are contingent claims of identity since the mental terms that figure in those statements are not rigid designators. However, Kripke maintained that our concepts of sensations and other qualitative states are not equivalent to the sorts of descriptions in question. The term ‘pain’, he maintained, is a rigid designator. This position might be refuted by a successful functional analysis of the concept of pain in physical and/or topic-neutral terms. However, no successful analysis of this sort has yet been produced. See the section on consciousness below. A materialist can grant Kripke that ‘pain’ is a rigid designator and claim that a statement such as ‘Pain is C-fiber firing’ will be metaphysically necessary if true, but only a posteriori knowable. However, Kripke raised a formidable problem for this materialism. He pointed out that if a statement is metaphysically necessary but only a posteriori knowable, its appearance of contingency calls for explanation. Despite being metaphysically necessary, ‘Water is H2O’ appears contingent. According to Kripke, we explain this appearance by noting that one can coherently imagine a world in which something has all the phenomenal properties of water, and so is an “epistemic counterpart” of it, yet is not H2O. The fact that we can coherently imagine such epistemic counterparts explains why ‘Water is H2O’ appears contingent. But no such explanation is available for e.g. ‘Pain is C-fiber firing’. For an epistemic counterpart of pain, something with the phenomenal properties of pain  the feel of pain  is pain. Something can look, smell, taste, and feel like water yet not be water. But whatever feels like pain is pain: pain is a feeling. In contrast, we can explain the apparent contingency of claims like ‘Water is H2O’ because water is not constituted by its phenomenal properties; our concept of water allows that it may have a “hidden essence,” i.e., an essential microstructure. If Kripke is right, then anyone who maintains that a statement of identity concerning a type of bodily sensation and a type of physical state is metaphysically necessary yet a posteriori, must explain the appearance of contingency in a way that differs from the way Kripke explains the appearance of contingency of ‘Water is H2O’. This is a formidable challenge. The final section, on consciousness, sketches some materialist responses to it. The general issue of property and state type identity is controversial. The claim that water is H2O despite the fact that the concept of water is distinct from the concept of H2O seems plausible. However, property or state type identity is more controversial than the identity of types of substances. For properties or state types, there are no generally accepted “non-duplication principles”  to use a phrase of David Lewis’s. A nonduplication principle for A’s will say that no two A’s can be exactly alike in a certain respect; e.g., no two sets can have exactly the same members. It is widely denied, for instance, that no two properties can be possessed by exactly the same things. Two properties, it is claimed, can be possessed by the same things; likewise, two state types can occur in the same space-time regions. Even assuming that mental concepts are distinct from physical concepts, the issue of whether mental state types are physical state types raises the controversial issue of the non-duplication principle for state types. Token and type physicalisms. Token physicalism is the thesis that every particular is physical. Type physicalism is the thesis that every type or kind of entity is physical; thus, the identity thesis and central state materialism are type physicalist theses since they imply that types of mental states are types of physical states. Type physicalism implies token physicalism: given the former, every token falls under some physical type, and therefore is token-token identical with some token of a physical type. But token physicalism does not imply type physicalism; the former leaves open whether physical tokens fall under non-physical types. Some doctrines billed as materialist or physicalist embrace token epiphenomenalism, but reject type physicalism. Non-reductive materialism. This form of materialism implies token physicalism, but denies type physicalism and, as well, that mental types properties, etc. are reducible to physical types. This doctrine has been discussed since at least the late nineteenth century and was widely discussed in the first third of the twentieth century. The British philosophers George Henry Lewes, Samuel Alexander, Lloyd Morgan, and C. D. Broad all held or thought plausible a certain version of non-reductive materialism. They held or sympathized with the view that every substance philosophy of mind philosophy of mind 689    689 either is or is wholly made up of physical particles, that the well-functioning brain is the material seat of mental capacities, and that token mental states events, processes, etc. are token neurophysiological states events, processes, etc.. However, they either held or thought plausible the view that mental capacities, properties, etc., emerge from, and thus do not reduce to, physical capacities, properties, etc. Lewes coined the term ‘emergence’; and Broad later labeled the doctrine emergent materialism. Emergent materialists maintain that laws correlating mental and physical properties are irreducible. These laws would be what Feigl called nomological danglers. Emergentists maintain that, despite their untidiness, such laws must be accepted with natural piety. Davidson’s doctrine of anomalous monism is a current brand of non-reductive materialism. He explicitly formulates this materialist thesis for events; and his irreducibility thesis is restricted to intentional mental types  e.g., believings, desirings, and intendings. Anomalous monism says that every event token is physical, but that intentional mental predicates and concepts ones expressing propositional attitudes do not reduce, by law or definition, to physical predicates or concepts. Davidson offers an original argument for this irreducibility thesis. Mental predicates and concepts are, he claims, governed by constitutive principles of rationality, but physical predicates and concepts are not. This difference, he contends, excludes the possibility of reduction of mental predicates and concepts to physical ones. Davidson denies, moreover, that there are strict psychological or psychophysical laws. He calls the conjunction of this thesis and his irreducibility thesis the principle of the anomalism of the mental. His argument for token physicalism for events appeals to the principle of the anomalism of the mental and to the principle of the nomological character of causality: when two events are causally related, they are subsumed by a strict law. He maintains that all strict laws are physical. Given that claim, and given the principle of the nomological character of causality, it follows that every event that is a cause or effect is a physical event. On this view, psychophysical causation is just causation between physical events. Stephen Schiffer has also maintained a non-reductive materialism, one he calls ontological physicalism and sentential dualism: every particular is physical, but mental truths are irreducible to physical truths. Non-reductive materialism presupposes that mental state event tokens can fall under physical state types and, thereby, count as physical state tokens. This presupposition is controversial; no uncontroversial non-duplication principle for state tokens settles the issue. Suppose, however, that mental state tokens are physical state tokens, despite mental state types not being physical state types. The issue of how mental state types and physical state types are related remains. Suppose that some physical token x is of a mental type M say, a belief that the cat is on the mat and some other physical token y is not of type M. There must, it seems, be some difference between x and y in virtue of which x is, and y is not, of type M. Otherwise, it is simply a brute fact that x is and y is not of type M. That, however, seems implausible. The claim that certain physical state tokens fall under mental state types simply as a matter of brute fact would leave the difference in question utterly mysterious. But if it is not a brute fact, then there is some explanation of why a certain physical state is a mental state of a certain sort. The non-reductive materialist owes us an explanation that does not imply psychophysical reduction. Moreover, even though the non-reductive materialist can claim that mental states are causes because they are physical states with physical effects, there is some question whether mental state types are relevant to causal relations. Suppose every state is a physical state. Given that physical states causally interact in virtue of falling under physical types, it follows that whenever states causally interact they do so in virtue of falling under physical types. That raises the issue of whether states are ever causes in virtue of falling under mental types. Type epiphenomenalism is the thesis that no state can cause anything in virtue of falling under a mental type. Token epiphenomenalism, the thesis that no mental state can cause anything, implies type epiphenomenalism, but not conversely. Nonreductive materialists are not committed to token physicalism. However, token epiphenomenalism may be false but type epiphenomenalism true since mental states may be causes only in virtue of falling under physical types, never in virtue of falling under mental types. Broad raised the issue of type epiphenomenalism and discussed whether emergent materialism is committed to it. Ted Honderich, Jaegwon Kim, Ernest Sosa, and others have in recent years raised the issue of whether non-reductive materialism is committed to type epiphenomenalism. Brian McLaughlin has argued that the claim that an event acts as a cause in virtue of falling under a certain physical type is consistent with the philosophy of mind philosophy of mind 690    690 claim that it also acts as a cause in virtue of falling under a certain mental type, even when the mental type is not identical with the physical type. But even if this is so, the relationship between mental types and physical types must be addressed. Ernest LePore and Barry Loewer, Frank Jackson and Philip Pettit, Stephen Yablo, and others have attempted to characterize a relation between mental types and physical types that allows for the causal relevance of mental types. But whether there is a relation between mental and physical properties that is both adequate to secure the causal relevance of mental properties and available to non-reductive materialists remains an open question. Davidson’s anomalous monism may appear to be a kind of dual-aspect theory: there are events and they can have two sorts of autonomous aspects, mental and physical. However, while Davidson holds that mental properties or types do not reduce to physical ones, he also holds that the mental properties of an event depend on its physical properties in that the former supervene on the latter in this sense: no two events can be exactly alike in every physical respect and yet differ in some mental respect. This proposal introduced the notion of supervenience into contem- porary philosophy of mind. Often nonreductive materialists argue that mental properties types supervene on physical properties types. Kim, however, has distinguished various supervenience relations, and argues that some are too weak to count as versions of materialism as opposed to, say, dual-aspect theory, while other supervenience relations are too strong to use to formulate non-reductive materialism since they imply reducibility. According to Kim, non-reductive materialism is an unstable position. Materialism as a supervenience thesis. Several philosophers have in recent years attempted to define the thesis of materialism using a global supervenience thesis. Their aim is not to formulate a brand of non-reductive materialism; they maintain that their supervenience thesis may well imply reducibility. Their aim is, rather, to formulate a thesis to which anyone who counts as a genuine materialist must subscribe. David Lewis has maintained that materialism is true if and only if any non-alien possible worlds that are physically indiscernible are mentally indiscernible as well. Non-alien possible worlds are worlds that have exactly the same perfectly natural properties as the actual world. Frank Jackson has offered this proposal: materialism is true if and only if any minimal physical duplicate of the actual world is a duplicate simpliciter of the actual world. A world is a physical duplicate of the actual world if and only if it is exactly like the actual world in every physical respect physical particular for physical particular, physical property for physical property, physical relation for physical relation, etc.; and a world is a duplicate simpliciter of the actual world if and only if it is exactly like the actual world in every respect. A minimal physical duplicate of the actual world is a physical duplicate that contains nothing else by way of particulars, kinds, properties, etc. than it must in order to be a physical duplicate of the actual world. Two questions arise for any formulation of the thesis of materialism. Is it adequate to materialism? And, if it is, is it true? Functionalism. The nineteenth-century British philosopher George Henry Lewes maintained that while not every neurological event is mental, every mental event is neurological. He claimed that what makes certain neurological events mental events is their causal role in the organism. This is a very early version of functionalism, nowadays a leading approach to the mindbody problem. Functionalism implies an answer to the question of what makes a state token a mental state of a certain kind M: namely, that it is an instance of some functional state type identical with M. There are two versions of this proposal. On one, a mental state type M of a system will be identical with the state type that plays a certain causal role R in the system. The description ‘the state type that plays R in the system’ will be a nonrigid designator; moreover, different state types may play R in different organisms, in which case the mental state is multiply realizable. On the second version, a mental state type M is identical with a second-order state type, the state of being in some first-order state that plays causal role R. More than one first-order state may play role R, and thus M may be multiply realizable. On either version, if the relevant causal roles are specifiable in physical or topic-neutral terms, then the functional definitions of mental state types will be, in principle, physically reductive. Since the roles would be specified partly in topic-neutral terms, there may well be possible worlds in which the mental states are realized by non-physical states; thus, functionalism does not imply token physicalism. However, functionalists typically maintain that, on the empirical evidence, mental states are realized in our world only by physical states. Functionalism comes in many varieties. philosophy of mind philosophy of mind 691    691 Smart’s topic-neutral analysis of our talk of sensations is in the spirit of functionalism. And Armstrong’s central state materialism counts as a kind of functionalism since it maintains that mental states are states apt to produce a certain range of behavior, and thus identifies states as mental states by their performing this causal role. However, functionalists today typically hold that the defining causal roles include causal roles vis-à-vis input state types, as well as output state types, and also vis-à-vis other internal state types of the system in question. In the 1960s David Lewis proposed a functionalist theory, analytical functionalism, according to which definitions of mental predicates such as ‘belief’, ‘desire’, and the like though not predicates such as ‘believes that p’ or ‘desires that q’ can be obtained by conjoining the platitudes of commonsense psychology and formulating the Ramsey sentence for the conjunction. The relevant Ramsey sentence is a second-order quantificational sentence that quantifies over the mental predicates in the conjunction of commonsense psychological platitudes, and from it one can derive definitions of the mental predicates. On this view, it will be analytic that a certain mental state e.g., belief is the state that plays a certain causal role vis-à-vis other states; and it is a matter of empirical investigation what state plays the role. Lewis claimed that such investigation reveals that the state types that play the roles in question are physical states. In the early 1960s, Putnam proposed a version of scientific functionalism, machine state functionalism: according to this view, mental states are types of Turing machine table states. Turing machines are mechanical devices consisting of a tape with squares on it that either are blank or contain symbols, and an executive that can move one square to the left, or one square to the right, or stay where it is. And it can either write a symbol on a square, erase a symbol on a square, or leave the square as it is. According to the Church-Turing thesis, every computable function can be computed by a Turing machine. Now there are two functions specifying such a machine: one from input states to output states, the other from input states to input states. And these functions are expressible by counterfactuals e.g., ‘If the machine is in state s 1 and receives input I, it will emit output O and enter state s2’. Machine tables are specified by the counterfactuals that express the functions in question. So the main idea of machine state functionalism is that any given mental type is definable as the state type that participates in certain counterfactual relationships specified in terms of purely formal, and so not semantically interpreted, state types. Any system whose inputs, outputs, and internal states are counterfactually related in the way characterized by a machine table is a realization of that table. This version of machine state functionalism has been abandoned: no one maintains that the mind has the architecture of a Turing machine. However, computational psychology, a branch of cognitive psychology, presupposes a scientific functionalist view of cognitive states: it takes the mind to have a computational architecture. See the section on cognitive psychology below. Functionalism  the view that what makes a state a realization of a mental state is its playing a certain causal role  remains a leading theory of mind. But functionalism faces formidable difficulties. Block has pinpointed one. On the one hand, if the input and output states that figure in the causal role alleged to define a certain mental state are specified in insufficient detail, the functional definition will be too liberal: it will mistakenly classify certain states as of that mental type. On the other hand, if the input and output states are specified in too much detail, the functional definition will be chauvinistic: it will fail to count certain states as instances of the mental state that are in fact such instances. Moreover, it has also been argued that functionalism cannot capture conscious states since types of conscious states do not admit of functional definitions. Cognitive psychology, content, and consciousness Cognitive psychology. Many claim that one aim of cognitive psychology is to provide explanations of intentional capacities, capacities to be in intentional states e.g., believing and to engage in intentional activities e.g., reasoning. Fodor has argued that classical cognitive psychology postulates a cognitive architecture that includes a language of thought: a system of mental representation with a combinatorial syntax and semantics, and computational processes defined over these mental representations in virtue of their syntactic structures. On this view, cognition is rule-governed symbol manipulation. Mental symbols have meanings, but they participate in computational processes solely in virtue of their syntactic or formal properties. The mind is, so to speak, a syntactic engine. The view implies a kind of content parallelism: syntaxsensitive causal transitions between symbols will preserve semantic coherence. Fodor has mainphilosophy of mind philosophy of mind 692    692 tained that, on this language-of-thought view of cognition the classical view, being in a beliefthat-p state can be understood as consisting in bearing a computational relation one that is constitutive of belief to a sentence in the language of thought that means that p; and similarly for desire, intention, and the like. The explanation of intentional capacities will be provided by a computational theory for mental sentences in conjunction with a psychosemantic theory, a theory of meaning for mental sentences. A research program in cognitive science called connectionism postulates networks of neuron-like units. The units can be either on or off, or can have continuous levels of activation. Units are connected, the connections have various degrees of strength, and the connections can be either inhibitory or excitatory. Connectionism has provided fruitful models for studying how neural networks compute information. Moreover, connectionists have had much success in modeling pattern recognition tasks e.g., facial recognition and tasks consisting of learning categories from examples. Some connectionists maintain that connectionism will yield an alternative to the classical language-of-thought account of intentional states and capacities. However, some favor a mixed-models approach to cognition: some cognitive capacities are symbolic, some connectionist. And some hold that connectionism will yield an implementational architecture for a symbolic cognitive architecture, one that will help explain how a symbolic cognitive architecture is realized in the nervous system. Content externalism. Many today hold that Twin-Earth thought experiments by Putnam and Tyler Burge show that the contents of a subject’s mental states do not supervene on intrinsic properties of the subject: two individuals can be exactly alike in every intrinsic respect, yet be in mental states with different contents. In response to Twin-Earth thought experiments, some philosophers have, however, attempted to characterize a notion of narrow content, a kind of content that supervenes on intrinsic properties of thinkers. Content, externalists claim, depends on extrinsic-contextual factors. If externalism is correct, then a psychosemantic theory must examine the relation between mental symbols and the extrinsic, contextual factors that determine contents. Stephen Stich has argued that psychology should eschew psychosemantics and concern itself only with the syntactic properties of mental sentences. Such a psychology could not explain intentional capacities. But Stich urges that computational psychology also eschew that explanatory goal. If, however, psychology is to explain intentional capacities, a psychosemantic theory is needed. Dretske, Fodor, Ruth Millikan, and David Papineau have each independently attempted to provide, in physicalistically respectable terms, foundations for a naturalized externalist theory of the content of mental sentences or internal physical states. Perhaps the leading problem for these theories of content is to explain how the physical and functional facts about a state determine a unique content for it. Appealing to work by Quine and by Kripke, some philosophers argue that such facts will not determine unique contents. Both causal and epistemic concerns have been raised about externalist theories of content. Such theories invite the question whether the property of having a certain content is ever causally relevant. If content is a contextual property of a state that has it, can states have effects in virtue of their having a certain content? This is an important issue because intentional states figure in explanations not only in virtue of their intentional mode whether they are beliefs, or desires, etc. but also in virtue of their contents. Consider an everyday belief-desire explanation. The fact that the subject’s belief was that there was milk in the refrigerator and the fact that the subject’s desire was for milk are both essential to the belief and desire explaining why the subject went to the refrigerator. Dretske, who maintains that content depends on a causal-historical context, has attempted to explain how the property of having a certain content can be causally relevant even though the possession of the property depends on causal-historical factors. And various other philosophers have attempted to explain how the causal relevance of content can be squared with the fact that it fails to supervene on intrinsic properties of the subject. A further controversial question is whether externalism is consistent with our having privileged access to what we are thinking. Consciousness. Conscious states such as pain states, visual experiences, and so on, are such that it is “like” something for the subject of the state to be in them. Such states have a qualitative aspect, a phenomenological character. The what-it-is-like aspects of experiences are called qualia. Qualia pose a serious difficulty for physicalism. Broad argued that one can know all the physical properties of a chemical and how it causally interacts with other physical phenomena and yet not know what it is like to smell it. He concluded that the smell of the chemical is philosophy of mind philosophy of mind 693    693 not itself a physical property, but rather an irreducible emergent property. Frank Jackson has recently defended a version of the argument, which has been dubbed the knowledge argument. Jackson argues that a super-scientist, Mary, who knows all the physical and functional facts about color vision, light, and matter, but has never experienced redness since she has spent her entire life in a black and white room, would not know what it is like to visually experience red. He concludes that the physical and functional topic-neutral facts do not entail all the facts, and thus materialism is false. In response, Lawrence Nemirow, David Lewis, and others have argued that knowing what it is like to be in a certain conscious state is, in part, a matter of know-how e.g., to be able to imagine oneself in the state rather than factual knowledge, and that the failure of knowledge of the physical and functional facts to yield such know-how does not imply the falsity of materialism. Functionalism seems unable to solve the problem of qualia since qualia seem not to be functionally definable. In the 1970s, Fodor and Ned Block argued that two states can have the same causal role, thereby realizing the same functional state, yet the qualia associated with each can be inverted. This is called the problem of inverted qualia. The color spectrum, e.g., might be inverted for two individuals a possibility raised by Locke, despite their being in the same functional states. They further argued that two states might realize the same functional state, yet the one might have qualia associated with it and the other not. This is called the problem of absent qualia. Sydney Shoemaker has argued that the possibility of absent qualia can be ruled out on functionalist grounds. However, he has also refined the inverted qualia scenario and further articulated the problem it poses for functionalism. Whether functionalism or physicalism can avoid the problems of absent and inverted qualia remains an open question. Thomas Nagel claims that conscious states are subjective: to fully understand them, one must understand what it is like to be in them, but one can do that only by taking up the experiential point of view of a subject in them. Physical states, in contrast, are objective. Physical science attempts to characterize the world in abstraction from the experiential point of view of any subject. According to Nagel, whether phenomenal mental states reduce to physical states turns on whether subjective states reduce to objective states; and, at present, he claims, we have no understanding of how they could. Nagel has suggested that consciousness may be explainable only by appeal to as yet undiscovered basic nonmental, non-physical properties  “proto-mental properties”  the idea being that experiential points of view might be constituted by protomental properties together with physical properties. He thus claims that panphysicism is worthy of serious consideration. Frank Jackson, James Van Cleve, and David Chalmers have argued that conscious properties are emergent, i.e., fundamental, irreducible macro-properties; and Chalmers sympathizes with a brand of panphysicism. Colin McGinn claims that while conscious properties are likely reductively explainable by brain properties, our minds seem conceptually closed to the explaining properties: we are unable to conceptualize them, just as a cat is unable to conceptualize a square root. Dennett attempts to explain consciousness in supervenient behaviorist terms. David Rosenthal argues that consciousness is a special case of intentionality  more specifically, that conscious states are just states we can come in a certain direct way to believe we are in. Dretske, William Lycan, and Michael Tye argue that conscious properties are intentional properties and physicalistically reducible. Patricia Churchland argues that conscious phenomena are reducible to neurological phenomena. Brian Loar contends that qualia are identical with either functional or neurological states of the brain; and Christopher Hill argues specifically that qualia are identical with neurological states. Loar and Hill attempt to explain away the appearance of contingency of psychophysical identity claims, but in a way different from the way Kripke attempts to explain the appearance of contingency of ‘Water is H2O’, since they concede that that mode of explanation is unavailable. They appeal to differences in the conceptual roles of neurological and functional concepts by contrast with phenomenal concepts. They argue that while such concepts are different, they answer to the same properties. The nature of consciousness thus remains a matter of dispute.  .

philosophy of psychology, the philosophical study of psychology. Psychology began to separate from philosophy with the work of the ninephilosophy of organism philosophy of psychology 694    694 teenth-century German experimentalists, especially Fechner 180187, Helmholtz 1821 94, and Wundt 18321920. In the first half of the twentieth century, the separation was completed in this country insofar as separate psychology departments were set up in most universities, psychologists established their own journals and professional associations, and experimental methods were widely employed, although not in every area of psychology the first experimental study of the effectiveness of a psychological therapy did not occur until 1963. Despite this achievement of autonomy, however, issues have remained about the nature of the connections, if any, that should continue between psychology and philosophy. One radical view, that virtually all such connections should be severed, was defended by the behaviorist John Watson in his seminal 1913 paper “Psychology as the Behaviorist Views It.” Watson criticizes psychologists, even the experimentalists, for relying on introspective methods and for making consciousness the subject matter of their discipline. He recommends that psychology be a purely objective experimental branch of natural science, that its theoretical goal be to predict and control behavior, and that it discard all reference to consciousness. In making behavior the sole subject of psychological inquiry, we avoid taking sides on “those time-honored relics of philosophical speculation,” namely competing theories about the mindbody problem, such as interactionism and parallelism. In a later work, published in 1925, Watson claimed that the success of behaviorism threatened the very existence of philosophy: “With the behavioristic point of view now becoming dominant, it is hard to find a place for what has been called philosophy. Philosophy is passing  has all but passed, and unless new issues arise which will give a foundation for a new philosophy, the world has seen its last great philosopher.” One new issue was the credibility of behaviorism. Watson gave no argument for his view that prediction and control of behavior should be the only theoretical goals of psychology. If the attempt to explain behavior is also legitimate, as some anti-behaviorists argue, then it would seem to be an empirical question whether that goal can be met without appealing to mentalistic causes. Watson and his successors, such as B. F. Skinner, cited no credible empirical evidence that it could, but instead relied primarily on philosophical arguments for banning postulation of mentalistic causes. As a consequence, behaviorists virtually guaranteed that philosophers of psychology would have at least one additional task beyond wrestling with traditional mind body issues: the analysis and criticism of behaviorism itself. Although behaviorism and the mindbody problem were never the sole subjects of philosophy of psychology, a much richer set of topics developed after 1950 when the so-called cognitive revolution occurred in American psychology. These topics include innate knowledge and the acquisition of transformational grammars, intentionality, the nature of mental representation, functionalism, mental imagery, the language of thought, and, more recently, connectionism. Such topics are of interest to many cognitive psychologists and those in other disciplines, such as linguistics and artificial intelligence, who contributed to the emerging discipline known as cognitive science. Thus, after the decline of various forms of behaviorism and the consequent rise of cognitivism, many philosophers of psychology collaborated more closely with psychologists. This increased cooperation was probably due not only to a broadening of the issues, but also to a methodological change in philosophy. In the period roughly between 1945 and 1975, conceptual analysis dominated both American and English philosophy of psychology and the closely related discipline, the philosophy of mind. Many philosophers took the position that philosophy was essentially an a priori discipline. These philosophers rarely cited the empirical studies of psychologists. In recent decades, however, philosophy of psychology has become more empirical, at least in the sense that more attention is being paid to the details of the empirical studies of psychologists. The result is more interchanges between philosophers and psychologists. Although interest in cognitive psychology appears to predominate in recent American philosophy of psychology, the new emphasis on empirical studies is also reflected in philosophic work on topics not directly related to cognitive psychology. For example, philosophers of psychology have written books in recent years on the clinical foundations of psychoanalysis, the foundations of behavior therapy and behavior modification, and self-deception. The emphasis on empirical data has been taken one step further by naturalists, who argue that in epistemology, at least, and perhaps in all areas of philosophy, philosophical questions should either be replaced by questions from empirical psychology or be answered by appeal to empirical studies in psychology and related disciplines. It is philosophy of psychology philosophy of psychology 695    695 still too early to predict the fruitfulness of the naturalist approach, but this new trend might well have pleased Watson. Taken to an extreme, naturalism would make philosophy dependent on psychology instead of the reverse and thus would further enhance the autonomy of psychology that Watson desired.

philosophy of religion, the subfield of philosophy devoted to the study of religious phenomena. Although religions are typically complex systems of theory and practice, including both myths and rituals, philosophers tend to concentrate on evaluating religious truth claims. In the major theistic traditions, Judaism, Christianity, and Islam, the most important of these claims concern the existence, nature, and activities of God. Such traditions commonly understand God to be something like a person who is disembodied, eternal, free, all-powerful, all-knowing, the creator and sustainer of the universe, and the proper object of human obedience and worship. One important question is whether this conception of the object of human religious activity is coherent; another is whether such a being actually exists. Philosophers of religion have sought rational answers to both questions. The major theistic traditions draw a distinction between religious truths that can be discovered and even known by unaided human reason and those to which humans have access only through a special divine disclosure or revelation. According to Aquinas, e.g., the existence of God and some things about the divine nature can be proved by unaided human reason, but such distinctively Christian doctrines as the Trinity and Incarnation cannot be thus proved and are known to humans only because God has revealed them. Theists disagree about how such divine disclosures occur; the main candidates for vehicles of revelation include religious experience, the teachings of an inspired religious leader, the sacred scriptures of a religious community, and the traditions of a particular church. The religious doctrines Christian traditions take to be the content of revelation are often described as matters of faith. To be sure, such traditions typically affirm that faith goes beyond mere doctrinal belief to include an attitude of profound trust in God. On most accounts, however, faith involves doctrinal belief, and so there is a contrast within the religious domain itself between faith and reason. One way to spell out the contrast  though not the only way  is to imagine that the content of revelation is divided into two parts. On the one hand, there are those doctrines, if any, that can be known by human reason but are also part of revelation; the existence of God is such a doctrine if it can be proved by human reason alone. Such doctrines might be accepted by some people on the basis of rational argument, while others, who lack rational proof, accept them on the authority of revelation. On the other hand, there are those doctrines that cannot be known by human reason and for which the authority of revelation is the sole basis. They are objects of faith rather than reason and are often described as mysteries of faith. Theists disagree about how such exclusive objects of faith are related to reason. One prominent view is that, although they go beyond reason, they are in harmony with it; another is that they are contrary to reason. Those who urge that such doctrines should be accepted despite the fact that, or even precisely because, they are contrary to reason are known as fideists; the famous slogan credo quia absurdum ‘I believe because it is absurd’ captures the flavor of extreme fideism. Many scholars regard Kierkegaard as a fideist on account of his emphasis on the paradoxical nature of the Christian doctrine that Jesus of Nazareth is God incarnate. Modern philosophers of religion have, for the most part, confined their attention to topics treatable without presupposing the truth of any particular tradition’s claims about revelation and have left the exploration of mysteries of faith to the theologians of various traditions. A great deal of philosophical work clarifying the concept of God has been prompted by puzzles that suggest some incoherence in the traditional concept. One kind of puzzle concerns the coherence of individual claims about the nature of God. Consider the traditional affirmation that God is allpowerful omnipotent. Reflection on this doctrine raises a famous question: Can God make a stone so heavy that even God cannot lift it? No matter how this is answered, it seems that there is at least one thing that even God cannot do, i.e., make such a stone or lift such a stone, and so it appears that even God cannot be all-powerful. Such puzzles stimulate attempts by philosophers to analyze the concept of omnipotence in a way that specifies more precisely the scope of the powers coherently attributable to an omnipotent being. To the extent that such attempts succeed, they foster a deeper understanding of the concept of God and, if God exists, of the divine nature. Another sort of puzzle concerns the consistency of attributing two or more properties to philosophy of religion philosophy of religion 696    696 God. Consider the claim that God is both immutable and omniscient. An immutable being is one that cannot undergo internal change, and an omniscient being knows all truths, and believes no falsehoods. If God is omniscient, it seems that God must first know and hence believe that it is now Tuesday and not believe that it is now Wednesday and later know and hence believe that it is now Wednesday and not believe that it is now Tuesday. If so, God’s beliefs change, and since change of belief is an internal change, God is not immutable. So it appears that God is not immutable if God is omniscient. A resolution of this puzzle would further contribute to enriching the philosophical understanding of the concept of God. It is, of course, one thing to elaborate a coherent concept of God; it is quite another to know, apart from revelation, that such a being actually exists. A proof of the existence of God would yield such knowledge, and it is the task of natural theology to evaluate arguments that purport to be such proofs. As opposed to revealed theology, natural theology restricts the assumptions fit to serve as premises in its arguments to things naturally knowable by humans, i.e., knowable without special revelation from supernatural sources. Many people have hoped that such natural religious knowledge could be universally communicated and would justify a form of religious practice that would appeal to all humankind because of its rationality. Such a religion would be a natural religion. The history of natural theology has produced a bewildering variety of arguments for the existence of God. The four main types are these: ontological arguments, cosmological arguments, teleological arguments, and moral arguments. The earliest and most famous version of the ontological argument was set forth by Anselm of Canterbury in chapter 2 of his Proslogion. It is a bold attempt to deduce the existence of God from the concept of God: we understand God to be a perfect being, something than which nothing greater can be conceived. Because we have this concept, God at least exists in our minds as an object of the understanding. Either God exists in the mind alone, or God exists both in the mind and as an extramental reality. But if God existed in the mind alone, then we could conceive of a being greater than that than which nothing greater can be conceived, namely, one that also existed in extramental reality. Since the concept of a being greater than that than which nothing greater can be conceived is incoherent, God cannot exist in the mind alone. Hence God exists not only in the mind but also in extramental reality. The most celebrated criticism of this form of the argument was Kant’s, who claimed that existence is not a real predicate. For Kant, a real predicate contributes to determining the content of a concept and so serves as a part of its definition. But to say that something falling under a concept exists does not add to the content of a concept; there is, Kant said, no difference in conceptual content between a hundred real dollars and a hundred imaginary dollars. Hence whether or not there exists something that corresponds to a concept cannot be settled by definition. The existence of God cannot be deduced from the concept of a perfect being because existence is not contained in the concept or the definition of a perfect being. Contemporary philosophical discussion has focused on a slightly different version of the ontological argument. In chapter 3 of Proslogion Anselm suggested that something than which nothing greater can be conceived cannot be conceived not to exist and so exists necessarily. Following this lead, such philosophers as Charles Hartshorne, Norman Malcolm, and Alvin Plantinga have contended that God cannot be a contingent being who exists in some possible worlds but not in others. The existence of a perfect being is either necessary, in which case God exists in every possible world, or impossible, in which case God exists in no possible worlds. On this view, if it is so much as possible that a perfect being exists, God exists in every possible world and hence in the actual world. The crucial premise in this form of the argument is the assumption that the existence of a perfect being is possible; it is not obviously true and could be rejected without irrationality. For this reason, Plantinga concedes that the argument does not prove or establish its conclusion, but maintains that it does make it rational to accept the existence of God. The key premises of various cosmological arguments are statements of obvious facts of a general sort about the world. Thus, the argument to a first cause begins with the observation that there are now things undergoing change and things causing change. If something is a cause of such change only if it is itself caused to change by something else, then there is an infinitely long chain of causes of change. But, it is alleged, there cannot be a causal chain of infinite length. Therefore there is something that causes change, but is not caused to change by anything else, i.e., a first cause. Many critics of this form of the arguphilosophy of religion philosophy of religion 697    697 ment deny its assumption that there cannot be an infinite causal regress or chain of causes. This argument also fails to show that there is only one first cause and does not prove that a first cause must have such divine attributes as omniscience, omnipotence, and perfect goodness. A version of the cosmological argument that has attracted more attention from contemporary philosophers is the argument from contingency to necessity. It starts with the observation that there are contingent beings  beings that could have failed to exist. Since contingent beings do not exist of logical necessity, a contingent being must be caused to exist by some other being, for otherwise there would be no explanation of why it exists rather than not doing so. Either the causal chain of contingent beings has a first member, a contingent being not caused by another contingent being, or it is infinitely long. If, on the one hand, the chain has a first member, then a necessary being exists and causes it. After all, being contingent, the first member must have a cause, but its cause cannot be another contingent being. Hence its cause has to be non-contingent, i.e., a being that could not fail to exist and so is necessary. If, on the other hand, the chain is infinitely long, then a necessary being exists and causes the chain as a whole. This is because the chain as a whole, being itself contingent, requires a cause that must be noncontingent since it is not part of the chain. In either case, if there are contingent beings, a necessary being exists. So, since contingent beings do exist, there is a necessary being that causes their existence. Critics of this argument attack its assumption that there must be an explanation for the existence of every contingent being. Rejecting the principle that there is a sufficient reason for the existence of each contingent thing, they argue that the existence of at least some contingent beings is an inexplicable brute fact. And even if the principle of sufficient reason is true, its truth is not obvious and so it would not be irrational to deny it. Accordingly, William Rowe b.1931 concludes that this version of the cosmological argument does not prove the existence of God, but he leaves open the question of whether it shows that theistic belief is reasonable. The starting point of teleological arguments is the phenomenon of goal-directedness in nature. Aquinas, e.g., begins with the claim that we see that things which lack intelligence act for an end so as to achieve the best result. Modern science has discredited this universal metaphysical teleology, but many biological systems do seem to display remarkable adaptations of means to ends. Thus, as William Paley 17431805 insisted, the eye is adapted to seeing and its parts cooperate in complex ways to produce sight. This suggests an analogy between such biological systems and human artifacts, which are known to be products of intelligent design. Spelled out in mechanical terms, the analogy grounds the claim that the world as a whole is like a vast machine composed of many smaller machines. Machines are contrived by intelligent human designers. Since like effects have like causes, the world as a whole and many of its parts are therefore probably products of design by an intelligence resembling the human but greater in proportion to the magnitude of its effects. Because this form of the argument rests on an analogy, it is known as the analogical argument for the existence of God; it is also known as the design argument since it concludes the existence of an intelligent designer of the world. Hume subjected the design argument to sustained criticism in his Dialogues Concerning Natural Religion. If, as most scholars suppose, the character Philo speaks for Hume, Hume does not actually reject the argument. He does, however, think that it warrants only the very weak conclusion that the cause or causes of order in the universe probably bear some remote analogy to human intelligence. As this way of putting it indicates, the argument does not rule out polytheism; perhaps different minor deities designed lions and tigers. Moreover, the analogy with human artificers suggests that the designer or designers of the universe did not create it from nothing but merely imposed order on already existing matter. And on account of the mixture of good and evil in the universe, the argument does not show that the designer or designers are morally admirable enough to deserve obedience or worship. Since the time of Hume, the design argument has been further undermined by the emergence of Darwinian explanations of biological adaptations in terms of natural selection that give explanations of such adaptations in terms of intelligent design stiff competition. Some moral arguments for the existence of God conform to the pattern of inference to the best explanation. It has been argued that the hypothesis that morality depends upon the will of God provides the best explanation of the objectivity of moral obligations. Kant’s moral argument, which is probably the best-known specimen of this type, takes a different tack. According to Kant, the complete good consists of perfect virtue rewarded with perfect happiness, and philosophy of religion philosophy of religion 698    698 virtue deserves to be rewarded with proportional happiness because it makes one worthy to be happy. If morality is to command the allegiance of reason, the complete good must be a real possibility, and so practical reason is entitled to postulate that the conditions necessary to guarantee its possibility obtain. As far as anyone can tell, nature and its laws do not furnish such a guarantee; in this world, apparently, the virtuous often suffer while the vicious flourish. And even if the operation of natural laws were to produce happiness in proportion to virtue, this would be merely coincidental, and hence finite moral agents would not have been made happy just because they had by their virtue made themselves worthy of happiness. So practical reason is justified in postulating a supernatural agent with sufficient goodness, knowledge, and power to ensure that finite agents receive the happiness they deserve as a reward for their virtue, though theoretical reason can know nothing of such a being. Critics of this argument have denied that we must postulate a systematic connection between virtue and happiness in order to have good reasons to be moral. Indeed, making such an assumption might actually tempt one to cultivate virtue for the sake of securing happiness rather than for its own sake. It seems therefore that none of these arguments by itself conclusively proves the existence of God. However, some of them might contribute to a cumulative case for the existence of God. According to Richard Swinburne, cosmological, teleological, and moral arguments individually increase the probability of God’s existence even though none of them makes it more probable than not. But when other evidence such as that deriving from providential occurrences and religious experiences is added to the balance, Swinburne concludes that theism becomes more probable than its negation. Whether or not he is right, it does appear to be entirely correct to judge the rationality of theistic belief in the light of our total evidence. But there is a case to be made against theism too. Philosophers of religion are interested in arguments against the existence of God, and fairness does seem to require admitting that our total evidence contains much that bears negatively on the rationality of belief in God. The problem of evil is generally regarded as the strongest objection to theism. Two kinds of evil can be distinguished. Moral evil inheres in the wicked actions of moral agents and the bad consequences they produce. An example is torturing the innocent. When evil actions are considered theologically as offenses against God, they are regarded as sins. Natural evils are bad consequences that apparently derive entirely from the operations of impersonal natural forces, e.g. the human and animal suffering produced by natural catastrophes such as earthquakes and epidemics. Both kinds of evil raise the question of what reasons an omniscient, omnipotent, and perfectly good being could have for permitting or allowing their existence. Theodicy is the enterprise of trying to answer this question and thereby to justify the ways of God to humans. It is, of course, possible to deny the presuppositions of the question. Some thinkers have held that evil is unreal; others have maintained that the deity is limited and so lacks the power or knowledge to prevent the evils that occur. If one accepts the presuppositions of the question, the most promising strategy for theodicy seems to be to claim that each evil God permits is necessary for some greater good or to avoid some alternative to it that is at least as bad if not worse. The strongest form of this doctrine is the claim made by Leibniz that this is the best of all possible worlds. It is unlikely that humans, with their cognitive limitations, could ever understand all the details of the greater goods for which evils are necessary, assuming that such goods exist; however, we can understand how some evils contribute to achieving goods. According to the soul-making theodicy of John Hick b.1922, which is rooted in a tradition going back to Irenaeus, admirable human qualities such as compassion could not exist except as responses to suffering, and so evil plays a necessary part in the formation of moral character. But this line of thought does not seem to provide a complete theodicy because much animal suffering occurs unnoticed by humans and child abuse often destroys rather than strengthens the moral character of its victims. Recent philosophical discussion has often focused on the claim that the existence of an omniscient, omnipotent, and perfectly good being is logically inconsistent with the existence of evil or of a certain quantity of evil. This is the logical problem of evil, and the most successful response to it has been the free will defense. Unlike a theodicy, this defense does not speculate about God’s reasons for permitting evil but merely argues that God’s existence is consistent with the existence of evil. Its key idea is that moral good cannot exist apart from libertarian free actions that are not causally determined. If God aims to produce moral good, God must create free creatures upon whose cooperation he must depend, philosophy of religion philosophy of religion 699    699 and so divine omnipotence is limited by the freedom God confers on creatures. Since such creatures are also free to do evil, it is possible that God could not have created a world containing moral good but no moral evil. Plantinga extends the defense from moral to natural evil by suggesting that it is also possible that all natural evil is due to the free actions of non-human persons such as Satan and his cohorts. Plantinga and Swinburne have also addressed the probabilistic problem of evil, which is the claim that the existence of evil disconfirms or renders improbable the hypothesis that God exists. Both of them argue for the conclusion that this is not the case. Finally, it is worth mentioning three other topics on which contemporary philosophers of religion have worked to good effect. Important studies of the meaning and use of religious language were stimulated by the challenge of logical positivism’s claim that theological language is cognitively meaningless. Defenses of such Christian doctrines as the Trinity, Incarnation, and Atonement against various philosophical objections have recently been offered by people committed to elaborating an explicitly Christian philosophy. And a growing appreciation of religious pluralism has both sharpened interest in questions about the cultural relativity of religious rationality and begun to encourage progress toward a comparative philosophy of religions. Such work helps to make philosophy of religion a lively and diverse field of inquiry. 

philosophy of science, the branch of philosophy that is centered on a critical examination of the sciences: their methods and their results. One branch of the philosophy of science, methodology, is closely related to the theory of knowledge. It explores the methods by which science arrives at its posited truths concerning the world and critically explores alleged rationales for these methods. Issues concerning the sense in which theories are accepted in science, the nature of the confirmation relation between evidence and hypothesis, the degree to which scientific claims can be falsified by observational data, and the like, are the concern of methodology. Other branches of the philosophy of science are concerned with the meaning and content of the posited scientific results and are closely related to metaphysics and the philosophy of language. Typical problems examined are the nature of scientific laws, the cognitive content of scientific theories referring to unobservables, and the structure of scientific explanations. Finally, philosophy of science explores specific foundational questions arising out of the specific results of the sciences. Typical questions explored might be metaphysical presuppositions of space-time theories, the role of probability in statistical physics, the interpretation of measurement in quantum theory, the structure of explanations in evolutionary biology, and the like. Concepts of the credibility of hypotheses. Some crucial concepts that arise when issues of the credibility of scientific hypotheses are in question are the following: Inductivism is the view that hypotheses can receive evidential support from their predictive success with respect to particular cases falling under them. If one takes the principle of inductive inference to be that the future will be like the past, one is subject to the skeptical objection that this rule is empty of content, and even self-contradictory, if any kind of “similarity” of cases is permitted. To restore content and consistency to the rule, and for other methodological purposes as well, it is frequently alleged that only natural kinds, a delimited set of “genuine” properties, should be allowed in the formulation of scientific hypotheses. The view that theories are first arrived at as creative hypotheses of the scientist’s imagination and only then confronted, for justificatory purposes, with the observational predictions deduced from them, is called the hypotheticodeductive model of science. This model is contrasted with the view that the very discovery of hypotheses is somehow “generated” out of accumulated observational data. The view that hypotheses are confirmed to the degree that they provide the “best explanatory account” of the data is often called abduction and sometimes called inference to the best explanation. The alleged relation that evidence bears to hypothesis, warranting its truth but not, generally, guaranteeing that truth, is called confirmation. Methodological accounts such as inductivism countenance such evidential warrant, frequently speaking of evidence as making a hypothesis probable but not establishing it with certainty. Probability in the confirmational context is supposed to be a relationship holding between propositions that is quantitative and is described philosophy of science philosophy of science 700    700 by the formal theory of probability. It is supposed to measure the “degree of support” that one proposition gives to another, e.g. the degree of support evidential statements give to a hypothesis allegedly supported by them. Scientific methodologists often claim that science is characterized by convergence. This is the claim that scientific theories in their historical order are converging to an ultimate, final, and ideal theory. Sometimes this final theory is said to be true because it corresponds to the “real world,” as in realist accounts of convergence. In pragmatist versions this ultimate theory is the defining standard of truth. It is sometimes alleged that one ground for choosing the most plausible theory, over and above conformity of the theory with the observational data, is the simplicity of the theory. Many versions of this thesis exist, some emphasizing formal elements of the theory and others, e.g., emphasizing paucity of ontological commitment by the theory as the measure of simplicity. It is sometimes alleged that in choosing which theory to believe, the scientific community opts for theories compatible with the data that make minimal changes in scientific belief necessary from those demanded by previously held theory. The believer in methodological conservatism may also try to defend such epistemic conservatism as normatively rational. An experiment that can decisively show a scientific hypothesis to be false is called a crucial experiment for the hypothesis. It is a thesis of many philosophers that for hypotheses that function in theories and can only confront observational data when conjoined with other theoretical hypotheses, no absolutely decisive crucial experiment can exist. Concepts of the structure of hypotheses. Here are some of the essential concepts encountered when it is the structure of scientific hypotheses that is being explored: In its explanatory account of the world, science posits novel entities and properties. Frequently these are alleged to be not accessible to direct observation. A theory is a set of hypotheses positing such entities and properties. Some philosophers of science divide the logical consequences of a theory into those referring only to observable things and features and those referring to the unobservables as well. Various reductionist, eliminationist, and instrumentalist approaches to theory agree that the full cognitive content of a theory is exhausted by its observational consequences reported by its observation sentences, a claim denied by those who espouse realist accounts of theories. The view that the parts of a theory that do not directly relate observational consequences ought not to be taken as genuinely referential at all, but, rather, as a “mere linguistic instrument” allowing one to derive observational results from observationally specifiable posits, is called instrumentalism. From this point of view terms putatively referring to unobservables fail to have genuine reference and individual non-observational sentences containing such terms are not individually genuinely true or false. Verificationism is the general name for the doctrine that, in one way or another, the semantic content of an assertion is exhausted by the conditions that count as warranting the acceptance or rejection of the assertion. There are many versions of verificationist doctrines that try to do justice both to the empiricist claim that the content of an assertion is its totality of empirical consequences and also to a wide variety of anti-reductionist intuitions about meaning. The doctrine that theoretical sentences must be strictly translatable into sentences expressed solely in observational terms in order that the theoretical assertions have genuine cognitive content is sometimes called operationalism. The “operation” by which a magnitude is determined to have a specified value, characterized observationally, is taken to give the very meaning of attributing that magnitude to an object. The doctrine that the meanings of terms in theories are fixed by the role the terms play in the theory as a whole is often called semantic holism. According to the semantic holist, definitions of theoretical terms by appeal to observational terms cannot be given, but all of the theoretical terms have their meaning given “as a group” by the structure of the theory as a whole. A related doctrine in confirmation theory is that confirmation accrues to whole theories, and not to their individual assertions one at a time. This is confirmational holism. To see another conception of cognitive content, conjoin all the sentences of a theory together. Then replace each theoretical term in the sentence so obtained with a predicate variable and existentially quantify over all the predicate variables so introduced. This is the Ramsey sentence for a finitely axiomatized theory. This sentence has the same logical consequences framable in the observational vocabulary alone as did the original theory. It is often claimed that the Ramsey sentence for a theory exhausts the cognitive content of the theory. The Ramsey senphilosophy of science philosophy of science 701    701 tence is supposed to “define” the meaning of the theoretical terms of the original theory as well as have empirical consequences; yet by asserting the existence of the theoretical properties, it is sometimes alleged to remain a realist construal of the theory. The latter claim is made doubtful, however, by the existence of “merely representational” interpretations of the Ramsey sentence. Theories are often said to be so related that one theory is reducible to another. The study of the relation theories bear to one another in this context is said to be the study of intertheoretic reduction. Such reductive claims can have philosophical origins, as in the alleged reduction of material objects to sense-data or of spatiotemporal relations to causal relations, or they can be scientific discoveries, as in the reduction of the theory of light waves to the theory of electromagnetic radiation. Numerous “models” of the reductive relation exist, appropriate for distinct kinds and cases of reduction. The term scientific realism has many and varied uses. Among other things that have been asserted by those who describe themselves as scientific realists are the claims that “mature” scientific theories typically refer to real features of the world, that the history of past falsifications of accepted scientific theories does not provide good reason for persistent skepticism as to the truth claims of contemporary theories, and that the terms of theories that putatively refer to unobservables ought to be taken at their referential face value and not reinterpreted in some instrumentalistic manner. Internal realism denies irrealist claims founded on the past falsification of accepted theories. Internal realists are, however, skeptical of “metaphysical” claims of “correspondence of true theories to the real world” or of any notion of truth that can be construed in radically non-epistemic terms. While theories may converge to some ultimate “true” theory, the notion of truth here must be understood in some version of a Peircian idea of truth as “ultimate warranted assertability.” The claim that any theory that makes reference to posited unobservable features of the world in its explanatory apparatus will always encounter rival theories incompatible with the original theory but equally compatible with all possible observational data that might be taken as confirmatory of the original theory is the claim of the underdetermination thesis. A generalization taken to have “lawlike force” is called a law of nature. Some suggested criteria for generalizations having lawlike force are the ability of the generalization to back up the truth of claims expressed as counterfactual conditions; the ability of the generalization to be confirmed inductively on the basis of evidence that is only a proper subset of all the particular instances falling under the generality; and the generalization having an appropriate place in the simple, systematic hierarchy of generalizations important for fundamental scientific theories of the world. The application of a scientific law to a given actual situation is usually hedged with the proviso that for the law’s predictions to hold, “all other, unspecified, features of the situation are normal.” Such a qualifying clause is called a ceteris paribus clause. Such “everything else being normal” claims cannot usually be “filled out,” revealing important problems concerning the “open texture” of scientific claims. The claim that the full specification of the state of the world at one time is sufficient, along with the laws of nature, to fix the full state of the world at any other time, is the claim of determinism. This is not to be confused with claims of total predictability, since even if determinism were true the full state of the world at a time might be, in principle, unavailable for knowledge. Concepts of the foundations of physical theories. Here, finally, are a few concepts that are crucial in discussing the foundations of physical theories, in particular theories of space and time and quantum theory: The doctrine that space and time must be thought of as a family of spatial and temporal relations holding among the material constituents of the universe is called relationism. Relationists deny that “space itself” should be considered an additional constituent of the world over and above the world’s material contents. The doctrine that “space itself” must be posited as an additional constituent of the world over and above ordinary material things of the world is substantivalism. Mach’s principle is the demand that all physical phenomena, including the existence of inertial forces used by Newton to argue for a substantivalist position, be explainable in purely relationist terms. Mach speculated that Newton’s explanation for the forces in terms of acceleration with respect to “space itself” could be replaced with an explanation resorting to the acceleration of the test object with respect to the remaining matter of the universe the “fixed stars”. In quantum theory the claim that certain philosophy of science philosophy of science 702    702 “conjugate” quantities, such as position and momentum, cannot be simultaneously “determined” to arbitrary degrees of accuracy is the uncertainty principle. The issue of whether such a lack of simultaneous exact “determination” is merely a limitation on our knowledge of the system or is, instead, a limitation on the system’s having simultaneous exact values of the conjugate quantities, is a fundamental one in the interpretation of quantum mechanics. Bell’s theorem is a mathematical result aimed at showing that the explanation of the statistical correlations that hold between causally noninteractive systems cannot always rely on the positing that when the systems did causally interact in the past independent values were fixed for some feature of each of the two systems that determined their future observational behavior. The existence of such “local hidden variables” would contradict the correlational predictions of quantum mechanics. The result shows that quantum mechanics has a profoundly “non-local” nature. Can quantum probabilities and correlations be obtained as averages over variables at some deeper level than those specifying the quantum state of a system? If such quantities exist they are called hidden variables. Many different types of hidden variables have been proposed: deterministic, stochastic, local, non-local, etc. A number of proofs exist to the effect that positing certain types of hidden variables would force probabilistic results at the quantum level that contradict the predictions of quantum theory. Complementarity was the term used by Niels Bohr to describe what he took to be a fundamental structure of the world revealed by quantum theory. Sometimes it is used to indicate the fact that magnitudes occur in conjugate pairs subject to the uncertainty relations. Sometimes it is used more broadly to describe such aspects as the ability to encompass some phenomena in a wave picture of the world and other phenomena in a particle picture, but implying that no one picture will do justice to all the experimental results. The orthodox formalization of quantum theory posits two distinct ways in which the quantum state can evolve. When the system is “unobserved,” the state evolves according to the deterministic Schrödinger equation. When “measured,” however, the system suffers a discontinuous “collapse of the wave packet” into a new quantum state determined by the outcome of the measurement process. Understanding how to reconcile the measurement process with the laws of dynamic evolution of the system is the measurement problem. Conservation and symmetry. A number of important physical principles stipulate that some physical quantity is conserved, i.e. that the quantity of it remains invariant over time. Early conservation principles were those of matter mass, of energy, and of momentum. These became assimilated together in the relativistic principle of the conservation of momentum-energy. Other conservation laws such as the conservation of baryon number arose in the theory of elementary particles. A symmetry in physical theory expressed the invariance of some structural feature of the world under some transformation. Examples are translation and rotation invariance in space and the invariance under transformation from one uniformly moving reference frame to another. Such symmetries express the fact that systems related by symmetry transformations behave alike in their physical evolution. Some symmetries are connected with space-time, such as those noted above, whereas others such as the symmetry of electromagnetism under socalled gauge transformations are not. A very important result of the mathematician Emma Noether shows that each conservation law is derivable from the existence of an associated underlying symmetry. Chaos theory and chaotic systems. In the history of the scientific study of deterministic systems, the paradigm of explanation has been the prediction of the future states of a system from a specification of its initial state. In order for such a prediction to be useful, however, nearby initial states must lead to future states that are close to one another. This is now known to hold only in exceptional cases. In general deterministic systems are chaotic systems, i.e., even initial states very close to one another will lead in short intervals of time to future states that diverge quickly from one another. Chaos theory has been developed to provide a wide range of concepts useful for describing the structure of the dynamics of such chaotic systems. The theory studies the features of a system that will determine if its evolution is chaotic or non-chaotic and provides the necessary descriptive categories for characterizing types of chaotic motion. Randomness. The intuitive distinction between a sequence that is random and one that is orderly plays a role in the foundations of probability theory and in the scientific study of philosophy of science philosophy of science 703    703 dynamical systems. But what is a random sequence? Subjectivist definitions of randomness focus on the inability of an agent to determine, on the basis of his knowledge, the future occurrences in the sequence. Objectivist definitions of randomness seek to characterize it without reference to the knowledge of any agent. Some approaches to defining objective randomness are those that require probability to be the same in the original sequence and in subsequences “mechanically” selectable from it, and those that define a sequence as random if it passes every “effectively constructible” statistical test for randomness. Another important attempt to characterize objective randomness compares the length of a sequence to the length of a computer program used to generate the sequence. The basic idea is that a sequence is random if the computer programs needed to generate the sequence are as long as the sequence itself. 

philosophy of the social sciences, the study of the logic and methods of the social sciences. Central questions include: What are the criteria of a good social explanation? How if at all are the social sciences distinct from the natural sciences? Is there a distinctive method for social research? Through what empirical procedures are social science assertions to be evaluated? Are there irreducible social laws? Are there causal relations among social phenomena? Do social facts and regularities require some form of reduction to facts about individuals? What is the role of theory in social explanation? The philosophy of social science aims to provide an interpretation of the social sciences that answers these questions. The philosophy of social science, like that of natural science, has both a descriptive and a prescriptive side. On the one hand, the field is about the social sciences  the explanations, methods, empirical arguments, theories, hypotheses, etc., that actually occur in the social science literature. This means that the philosopher needs extensive knowledge of several areas of social science research in order to be able to formulate an analysis of the social sciences that corresponds appropriately to scientists’ practice. On the other hand, the field is epistemic: it is concerned with the idea that scientific theories and hypotheses are put forward as true or probable, and are justified on rational grounds empirical and theoretical. The philosopher aims to provide a critical evaluation of existing social science methods and practices insofar as these methods are found to be less truth-enhancing than they might be. These two aspects of the philosophical enterprise suggest that philosophy of social science should be construed as a rational reconstruction of existing social science practice  a reconstruction guided by existing practice but extending beyond that practice by identifying faulty assumptions, forms of reasoning, and explanatory frameworks. Philosophers have disagreed over the relation between the social and natural sciences. One position is naturalism, according to which the methods of the social sciences should correspond closely to those of the natural sciences. This position is closely related to physicalism, the doctrine that all higher-level phenomena and regularities  including social phenomena  are ultimately reducible to physical entities and the laws that govern them. On the other side is the view that the social sciences are inherently distinct from the natural sciences. This perspective holds that social phenomena are metaphysically distinguishable from natural phenomena because they are intentional  they depend on the meaningful actions of individuals. On this view, natural phenomena admit of causal explanation, whereas social phenomena require intentional explanation. The anti-naturalist position also maintains that there is a corresponding difference between the methods appropriate to natural and social science. Advocates of the Verstehen method hold that there is a method of intuitive interpretation of human action that is radically distinct from methods of inquiry in the natural sciences. One important school within the philosophy of social science takes its origin in this fact of the meaningfulness of human action. Interpretive sociology maintains that the goal of social inquiry is to provide interpretations of human conduct within the context of culturally specific meaningful arrangements. This approach draws an analogy between literary texts and social phenomena: both are complex systems of meaningful elements, and the goal of the interpreter is to provide an interpretation of the elements that makes sense of them. In this respect social science involves a hermeneutic inquiry: it requires that the interpreter should tease out the meanings underlying a particular complex of social behavior, much as a literary critic pieces together an interpretation of the meaning of a complex philosophy of the social sciences philosophy of the social sciences 704    704 literary text. An example of this approach is Weber’s treatment of the relation between capitalism and the Protestant ethic. Weber attempts to identify the elements of western European culture that shaped human action in this environment in such a way as to produce capitalism. On this account, both Calvinism and capitalism are historically specific complexes of values and meanings, and we can better understand the emergence of capitalism by seeing how it corresponds to the meaningful structures of Calvinism. Interpretive sociologists often take the meaningfulness of social phenomena to imply that social phenomena do not admit of causal explanation. However, it is possible to accept the idea that social phenomena derive from the purposive actions of individuals without relinquishing the goal of providing causal explanations of social phenomena. For it is necessary to distinguish between the general idea of a causal relation between two events or conditions and the more specific idea of “causal determination through strict laws of nature.” It is true that social phenomena rarely derive from strict laws of nature; wars do not result from antecedent political tensions in the way that earthquakes result from antecedent conditions in plate tectonics. However, since non-deterministic causal relations can derive from the choices of individual persons, it is evident that social phenomena admit of causal explanation, and in fact much social explanation depends on asserting causal relations between social events and processes  e.g., the claim that the administrative competence of the state is a crucial causal factor in determining the success or failure of a revolutionary movement. A central goal of causal explanation is to discover the conditions existing prior to the event that, given the law-governed regularities among phenomena of this sort, were sufficient to produce this event. To say that C is a cause of E is to assert that the occurrence of C, in the context of a field of social processes and mechanisms F, brought about E or increased the likelihood of the occurrence of E. Central to causal arguments in the social sciences is the idea of a causal mechanism  a series of events or actions leading from cause to effect. Suppose it is held that the extension of a trolley line from the central city to the periphery caused the deterioration of public schools in the central city. In order to make out such a claim it is necessary to provide some account of the social and political mechanisms that join the antecedent condition to the consequent. An important variety of causal explanation in social science is materialist explanation. This type of explanation attempts to explain a social feature in terms of features of the material environment in the context of which the social phenomenon occurs. Features of the environment that often appear in materialist explanations include topography and climate; thus it is sometimes maintained that banditry thrives in remote regions because the rugged terrain makes it more difficult for the state to repress bandits. But materialist explanations may also refer to the material needs of society  e.g., the need to produce food and other consumption goods to support the population. Thus Marx holds that it is the development of the “productive forces” technology that drives the development of property relations and political systems. In each case the materialist explanation must refer to the fact of human agency  the fact that human beings are capable of making deliberative choices on the basis of their wants and beliefs  in order to carry out the explanation; in the banditry example, the explanation depends on the fact that bandits are prudent enough to realize that their prospects for survival are better in the periphery than in the core. So materialist explanations too accept the point that social phenomena depend on the purposive actions of individuals. A central issue in the philosophy of social science involves the relation between social regularities and facts about individuals. Methodological individualism is the position that asserts the primacy of facts about individuals over facts about social entities. This doctrine takes three forms: a claim about social entities, a claim about social concepts, and a claim about social regularities. The first version maintains that social entities are reducible to ensembles of individuals  as an insurance company might be reduced to the ensemble of employees, supervisors, managers, and owners whose actions constitute the company. Likewise, it is sometimes held that social concepts must be reducible to concepts involving only individuals  e.g., the concept of a social class might be defined in terms of concepts pertaining only to individuals and their behavior. Finally, it is sometimes held that social regularities must be derivable from regularities of individual behavior. There are several positions opposed to methodological individualism. At the extreme there is methodological holism  the doctrine that social entities, facts, and laws are autonomous and irreducible; for example, that social structures such as the state have dynamic properties independent of the beliefs and purphilosophy of the social sciences philosophy of the social sciences 705    705 poses of the particular persons who occupy positions within the structure. A third position intermediate between these two holds that every social explanation requires microfoundations  an account of the circumstances at the individual level that led individuals to behave in such ways as to bring about the observed social regularities. If we observe that an industrial strike is successful over an extended period of time, it is not sufficient to explain this circumstance by referring to the common interest that members of the union have in winning their demands. Rather, we need information about the circumstances of the individual union member that induce him or her to contribute to this public good. The microfoundations dictum does not require, however, that social explanations be couched in non-social concepts; instead, the circumstances of individual agents may be characterized in social terms. Central to most theories of explanation is the idea that explanation depends on general laws governing the phenomena in question. Thus the discovery of the laws of electrodynamics permitted the explanation of a variety of electromagnetic phenomena. But social phenomena derive from the actions of purposive men and women; so what kinds of regularities are available on the basis of which to provide social explanations? A fruitful research framework in the social sciences is the idea that men and women are rational, so it is possible to explain their behavior as the outcome of a deliberation about means of achieving their individual ends. This fact in turn gives rise to a set of regularities about individual behavior that may be used as a ground for social explanation. We may explain some complex social phenomenon as the aggregate result of the actions of a large number of individual agents with a hypothesized set of goals within a structured environment of choice. Social scientists have often been inclined to offer functional explanations of social phenomena. A functional explanation of a social feature is one that explains the presence and persistence of the feature in terms of the beneficial consequences the feature has for the ongoing working of the social system as a whole. It might be held, e.g., that sports clubs in working-class Britain exist because they give working-class people a way of expending energy that would otherwise go into struggles against an exploitative system, thus undermining social stability. Sports clubs are explained, then, in terms of their contribution to social stability. This type of explanation is based on an analogy between biology and sociology. Biologists explain species traits in terms of their contribution to reproductive fitness, and sociologists sometimes explain social traits in terms of their contribution to “social” fitness. However, the analogy is misleading, because there is a general mechanism establishing functionality in the biological realm that is not present in the social realm. This is the mechanism of natural selection, through which a species arrives at a set of traits that are locally optimal. There is no analogous process at work in the social realm, however; so it is groundless to suppose that social traits exist because of their beneficial consequences for the good of society as a whole or important subsystems within society. So functional explanations of social phenomena must be buttressed by specific accounts of the causal processes that underlie the postulated functional relationships. 

physicalism: one of the twelve labours of Grice. in the widest sense of the term, materialism applied to the question of the nature of mind. So construed, physicalism is the thesis  call it ontological physicalism  that whatever exists or occurs is ultimately constituted out of physical entities. But sometimes ‘physicalism’ is used to refer to the thesis that whatever exists or occurs can be completely described in the vocabulary of physics. Such a view goes with either reductionism or eliminativism about the mental. Here reductionism is the view that psychological explanations, including explanations in terms of “folk-psychological” concepts such as those of belief and desire, are reducible to explanations formulable in a physical vocabulary, which in turn would imply that entities referred to in psychological explanations can be fully described in physical terms; and elminativism is the view that nothing corresponds to the terms in psychological explanations, and that the only correct explanations are in physical terms. The term ‘physicalism’ appears to have originated in the Vienna Circle, and the reductionist Philo the Megarian physicalism 706    706 physical realization pi 707 version initially favored there was a version of behaviorism: psychological statements were held to be translatable into behavioral statements, mainly hypothetical conditionals, expressible in a physical vocabulary. The psychophysical identity theory held by Herbert Feigl, Smart, and others, sometimes called type physicalism, is reductionist in a somewhat different sense. This holds that mental states and events are identical with neurophysiological states and events. While it denies that there can be analytic, meaning-preserving translations of mental statements into physicalistic ones, it holds that by means of synthetic “bridge laws,” identifying mental types with physical ones, mental statements can in principle be translated into physicalistic ones with which they are at least nomologically equivalent if the terms in the bridge laws are rigid designators, the equivalence will be necessary. The possibility of such a translation is typically denied by functionalist accounts of mind, on the grounds that the same mental state may have indefinitely many different physical realizations, and sometimes on the grounds that it is logically possible, even if it never happens, that mental states should be realized non-physically. In his classic paper “The ‘mental’ and the ‘physical’ “ 1958, Feigl distinguishes two senses of ‘physical’: ‘physical1’ and ‘physical2’. ‘Physical1’ is practically synonymous with ‘scientific’, applying to whatever is “an essential part of the coherent and adequate descriptive and explanatory account of the spatiotemporal world.” ‘Physical2’ refers to “the type of concepts and laws which suffice in principle for the explanation and prediction of inorganic processes.” It would seem that if Cartesian dualism were true, supposing that possible, then once an integrated science of the interaction of immaterial souls and material bodies had been developed, concepts for describing the former would count as physical1. Construed as an ontological doctrine, physicalism says that whatever exists or occurs is entirely constituted out of those entities that constitute inorganic things and processes. Construed as a reductionist or elminativist thesis about description and explanation, it is the claim that a vocabulary adequate for describing and explaining inorganic things and processes is adequate for describing and explaining whatever exists. While the second of these theses seems to imply the first, the first does not imply the second. It can be questioned whether the notion of a “full” description of what exists makes sense. And many ontological physicalists materialists hold that a reduction to explanations couched in the terminology of physics is impossible, not only in the case of psychological explanations but also in the case of explanations couched in the terminology of such special sciences as biology. Their objection to such reduction is not merely that a purely physical description of e.g. biological or psychological phenomena would be unwieldy; it is that such descriptions necessarily miss important laws and generalizations, ones that can only be formulated in terms of biological, psychological, etc., concepts. If ontological physicalists materialists are not committed to the reducibility of psychology to physics, neither are they committed to any sort of identity theory claiming that entities picked out by mental or psychological descriptions are identical to entities fully characterizable by physical descriptions. As already noted, materialists who are functionalists deny that there are typetype identities between mental entities and physical ones. And some deny that materialists are even committed to token-token identities, claiming that any psychological event could have had a different physical composition and so is not identical to any event individuated in terms of a purely physical taxonomy. 

physis, Grecian term for nature, primarily used to refer to the nature or essence of a living thing Aristotle, Metaphysics V.4. Physis is defined by Aristotle in Physics II.1 as a source of movement and rest that belongs to something in virtue of itself, and identified by him primarily with the form, rather than the matter, of the thing. The term is also used to refer to the natural world as a whole. Physis is often contrasted with techne, art; in ethics it is also contrasted with nomos, convention, e.g. by Callicles in Plato’s Gorgias 482e ff., who distinguishes natural from conventional justice. 

pi, Chinese term meaning ‘screen’, ‘shelter’, or ‘cover’. Pi is Hsün Tzu’s metaphor for an obscuration or blindness of mind. In this condition the mind is obstructed in its proper functioning, e.g., thinking, remembering, imagining, and judging. In short, a pi is anything that obstructs the mind’s    707 Piaget, Jean Plantinga, Alvin 708 cognitive task. When the mind is in the state of pi, reason is, so to speak, not operating properly. The opposite of pi is clarity of mind, a precondition for the pursuit of knowledge. A.S.C. Piaget, Jean 18961980, Swiss psychologist and epistemologist who profoundly influenced questions, theories, and methods in the study of cognitive development. The philosophical interpretation and implications of his work, however, remain controversial. Piaget regarded himself as engaged in genetic epistemology, the study of what knowledge is through an empirical investigation of how our epistemic relations to objects are improved. Piaget hypothesized that our epistemic relations are constructed through the progressive organization of increasingly complex behavioral interactions with physical objects. The cognitive system of the adult is neither learned, in the Skinnerian sense, nor genetically preprogrammed. Rather, it results from the organization of specific interactions whose character is shaped both by the features of the objects interacted with a process called accommodation and by the current cognitive system of the child a process called assimilation. The tendency toward equilibrium results in a change in the nature of the interaction as well as in the cognitive system. Of particular importance for the field of cognitive development were Piaget’s detailed descriptions and categorizations of changes in the organization of the cognitive system from birth through adolescence. That work focused on changes in the child’s understanding of such things as space, time, cause, number, length, weight, and morality. Among his major works are The Child’s Conception of Number 1941, Biology and Knowledge 1967, Genetic Epistemology 1970, and Psychology and Epistemology 1970. 

Pico della Mirandola, Giovanni 146394, Italian philosopher who, in 1486, wrote a series of 900 theses which he hoped to dispute publicly in Rome. Thirteen of these were criticized by a papal commission. When Pico defended himself in his Apology, the pope condemned all 900 theses. Pico fled to France, but was briefly imprisoned there in 1488. On his release, he returned to Florence and devoted himself to private study. He hoped to write a Concord of Plato and Aristotle, but the only part he was able to complete was On Being and the One 1492, in which he uses Aquinas and Christianity to reconcile Plato’s and Aristotle’s views about God’s being and unity. He is often described as a syncretist, but in fact he made it clear that the truth of Christianity has priority over the prisca theologia or ancient wisdom found in the hermetic corpus and the cabala. Though he was interested in magic and astrology, he adopts a guarded attitude toward them in his Heptaplus 1489, which contains a mystical interpretation of Genesis; and in his Disputations Against Astrology, published posthumously, he rejects them both. The treatise is largely technical, and the question of human freedom is set aside as not directly relevant. This fact casts some doubt on the popular thesis that Pico’s philosophy was a celebration of man’s freedom and dignity. Great weight has been placed on Pico’s most famous work, On the Dignity of Man 1486. This is a short oration intended as an introduction to the disputation of his 900 theses, and the title was invented after his death. Pico has been interpreted as saying that man is set apart from the rest of creation, and is completely free to form his own nature. In fact, as the Heptaplus shows, Pico saw man as a microcosm containing elements of the angelic, celestial, and elemental worlds. Man is thus firmly within the hierarchy of nature, and is a bond and link between the worlds. In the oration, the emphasis on freedom is a moral one: man is free to choose between good and evil.

pien, Chinese Mohist technical term for disputation, defined as ‘contending over converse claims’. It involves discrimination between what does and does not “fit the facts.” In Hsün Tzu, pien as discrimination pertains especially to the ability to distinguish mental states such as anger, grief, love, hate, and desires as well as proper objects of different senses. Pien is significantly used in the context of justification as a phase in ethical argumentation. Among other things, pien as justification pertains to projection of the significance of comparable past ethical experiences to present “hard cases” of human life. A.S.C. pien che.

Plantinga, Alvin b.1932, one of the most important twentieth-century American philosophers    708 of religion. His ideas have determined the direction of debate in many aspects of the discipline. He has also contributed substantially to analytic epistemology and the metaphysics of modality. Plantinga is currently director of the Center for Philosophy of Religion and John O’Brien Professor of Philosophy at the  of Notre Dame. Plantinga’s philosophy of religion has centered on the epistemology of religious belief. His God and Other Minds 1967 introduced a defining claim of his career  that belief in God may be rational even if it is not supported by successful arguments from natural theology. This claim was fully developed in a series of articles published in the 1980s, in which he argued for the position he calls “Reformed Epistemology.” Borrowing from the work of theologians such as Calvin, Bavinck, and Barth, Plantinga reasoned that theistic belief is “properly basic,” justified not by other beliefs but by immediate experience. This position was most thoroughly treated in his article “Reason and Belief in God” Plantinga and Wolterstorff, eds., Faith and Rationality, 1983. In early work Plantinga assumed an internalist view of epistemic justification. Later he moved to externalism, arguing that basic theistic belief would count as knowledge if true and appropriately produced. He developed this approach in “Justification and Theism” Faith and Philosophy, 1987. These ideas led to the development of a full-scale externalist epistemological theory, first presented in his 1989 Gifford Lectures and later published in the two-volume set Warrant: The Current Debate and Warrant and Proper Function 1993. This theory has become the focal point of much contemporary debate in analytic epistemology. Plantinga is also a leading theorist in the metaphysics of modality. The Nature of Necessity 1974 developed a possible worlds semantics that has become standard in the literature. His analysis of possible worlds as maximally consistent states of affairs offers a realist compromise between nominalist and extreme reificationist conceptions. In the last two chapters, Plantinga brings his modal metaphysics to bear on two classical topics in the philosophy of religion. He presented what many consider the definitive version of the free will defense against the argument from evil and a modal version of the ontological argument that may have produced more response than any version since Anselm’s original offering. 

Plato: preeminent Grecian philosopher whose chief contribution consists in his conception of the observable world as an imperfect image of a realm of unobservable and unchanging “Forms,” and his conception of the best life as one centered on the love of these divine objects. Life and influences. Born in Athens to a politically powerful and aristocratic family, Plato came under the influence of Socrates during his youth and set aside his ambitions for a political career after Socrates was executed for impiety. His travels in southern Italy and Sicily brought him into closer contact with the followers of Pythagoras, whose research in mathematics played an important role in his intellectual development. He was also acquainted with Cratylus, a follower of Heraclitus, and was influenced by their doctrine that the world is in constant flux. He wrote in opposition to the relativism of Protagoras and the purely materialistic mode of explanation adopted by Democritus. At the urging of a devoted follower, Dion, he became involved in the politics of Syracuse, the wealthiest city of the Grecian world, but his efforts to mold the ideas of its tyrant, Dionysius II, were unmitigated failures. These painful events are described in Plato’s Letters Epistles, the longest and most important of which is the Seventh Letter, and although the authenticity of the Letters is a matter of controversy, there is little doubt that the author was well acquainted with Plato’s life. After returning from his first visit to Sicily in 387, Plato established the Academy, a fraternal association devoted to research and teaching, and named after the sacred site on the outskirts of Athens where it was located. As a center for political training, it rivaled the school of Isocrates, which concentrated entirely on rhetoric. The bestknown student of the Academy was Aristotle, who joined at the age of seventeen when Plato was sixty and remained for twenty years. Chronology of the works. Plato’s works, many of which take the form of dialogues between Socrates and several other speakers, were composed over a period of about fifty years, and this has led scholars to seek some pattern of philosophical development in them. Increasingly sophisticated stylometric tests have been devised to calculate the linguistic similarities among the dialogues. Ancient sources indicate that the Laws was Plato’s last work, and there is now consensus that many affinities exist between the style of this work and several others, which can therePlato Plato 709    709 fore also be safely regarded as late works; these include the Sophist, Statesman, and Philebus perhaps written in that order. Stylometric tests also support a rough division of Plato’s other works into early and middle periods. For example, the Apology, Charmides, Crito, Euthyphro, Hippias Minor, Ion, Laches, and Protagoras listed alphabetically are widely thought to be early; while the Phaedo, Symposium, Republic, and Phaedrus perhaps written in that order are agreed to belong to his middle period. But in some cases it is difficult or impossible to tell which of two works belonging to the same general period preceded the other; this is especially true of the early dialogues. The most controversial chronological question concerns the Timaeus: stylometric tests often place it with the later dialogues, though some scholars think that its philosophical doctrines are discarded in the later dialogues, and they therefore assign it to Plato’s middle period. The underlying issue is whether he abandoned some of the main doctrines of this middle period. Early and middle dialogues. The early dialogues typically portray an encounter between Socrates and an interlocutor who complacently assumes that he understands a common evaluative concept like courage, piety, or beauty. For example, Euthyphro, in the dialogue that bears his name, denies that there is any impiety in prosecuting his father, but repeated questioning by Socrates shows that he cannot say what single thing all pious acts have in common by virtue of which they are rightly called pious. Socrates professes to have no answer to these “What is X?” questions, and this fits well with the claim he makes in the Apology that his peculiarly human form of wisdom consists in realizing how little he knows. In these early dialogues, Socrates seeks but fails to find a philosophically defensible theory that would ground our use of normative terms. The Meno is similar to these early dialogues  it asks what virtue is, and fails to find an answer  but it goes beyond them and marks a transition in Plato’s thinking. It raises for the first time a question about methodology: if one does not have knowledge, how is it possible to acquire it simply by raising the questions Socrates poses in the early dialogues? To show that it is possible, Plato demonstrates that even a slave ignorant of geometry can begin to learn the subject through questioning. The dialogue then proposes an explanation of our ability to learn in this way: the soul acquired knowledge before it entered the body, and when we learn we are really recollecting what we once knew and forgot. This bold speculation about the soul and our ability to learn contrasts with the noncommittal position Socrates takes in the Apology, where he is undecided whether the dead lose all consciousness or continue their activities in Hades. The confidence in immortality evident in the Meno is bolstered by arguments given in the Phaedo, Republic, and Phaedrus. In these dialogues, Plato uses metaphysical considerations about the nature of the soul and its ability to learn to support a conception of what the good human life is. Whereas the Socrates of the early dialogues focuses almost exclusively on ethical questions and is pessimistic about the extent to which we can answer them, Plato, beginning with the Meno and continuing throughout the rest of his career, confidently asserts that we can answer Socratic questions if we pursue ethical and metaphysical inquiries together. The Forms. The Phaedo is the first dialogue in which Plato decisively posits the existence of the abstract objects that he often called “Forms” or “Ideas.” The latter term should be used with caution, since these objects are not creations of a mind, but exist independently of thought; the singular Grecian terms Plato often uses to name these abstract objects are eidos and idea. These Forms are eternal, changeless, and incorporeal; since they are imperceptible, we can come to have knowledge of them only through thought. Plato insists that it would be an error to identify two equal sticks with what Equality itself is, or beautiful bodies with what Beauty itself is; after all, he says, we might mistakenly take two equal sticks to be unequal, but we would never suffer from the delusion that Equality itself is unequal. The unchanging and incorporeal Form is the sort of object that is presupposed by Socratic inquiry; what every pious act has in common with every other is that it bears a certain relationship  called “participation”  to one and the same thing, the Form of Piety. In this sense, what makes a pious act pious and a pair of equal sticks equal are the Forms Piety and Equality. When we call sticks equal or acts pious, we are implicitly appealing to a standard of equality or piety, just as someone appeals to a standard when she says that a painted portrait of someone is a man. Of course, the pigment on the canvas is not a man; rather, it is properly called a man because it bears a certain relationship to a very different sort of object. In precisely this way, Plato claims that the Forms are what many of our words refer to, even though they are radically different sorts of objects from the ones revealed to the senses. Plato Plato 710    710 Love. For Plato the Forms are not merely an unusual item to be added to our list of existing objects. Rather, they are a source of moral and religious inspiration, and their discovery is therefore a decisive turning point in one’s life. This process is described by a fictional priestess named Diotima in the Symposium, a dialogue containing a series of speeches in praise of love and concluding with a remarkable description of the passionate response Socrates inspired in Alcibiades, his most notorious admirer. According to Diotima’s account, those who are in love are searching for something they do not yet understand; whether they realize it or not, they seek the eternal possession of the good, and they can obtain it only through productive activity of some sort. Physical love perpetuates the species and achieves a lower form of immortality, but a more beautiful kind of offspring is produced by those who govern cities and shape the moral characteristics of future generations. Best of all is the kind of love that eventually attaches itself to the Form of Beauty, since this is the most beautiful of all objects and provides the greatest happiness to the lover. One develops a love for this Form by ascending through various stages of emotional attachment and understanding. Beginning with an attraction to the beauty of one person’s body, one gradually develops an appreciation for the beauty present in all other beautiful bodies; then one’s recognition of the beauty in people’s souls takes on increasing strength, and leads to a deeper attachment to the beauty of customs, laws, and systems of knowledge; and this process of emotional growth and deepening insight eventually culminates in the discovery of the eternal and changeless beauty of Beauty itself. Plato’s theory of erotic passion does not endorse “Platonic love,” if that phrase designates a purely spiritual relationship completely devoid of physical attraction or expression. What he insists on is that desires for physical contact be restrained so that they do not subvert the greater good that can be accomplished in human relationships. His sexual orientation like that of many of his Athenian contemporaries is clearly homosexual, and he values the moral growth that can occur when one man is physically attracted to another, but in Book I of the Laws he condemns genital activity when it is homosexual, on the ground that such activity should serve a purely procreative purpose. Plato’s thoughts about love are further developed in the Phaedrus. The lover’s longing for and physical attraction to another make him disregard the norms of commonplace and dispassionate human relationships: love of the right sort is therefore one of four kinds of divine madness. This fourfold classificatory scheme is then used as a model of proper methodology. Starting with the Phaedrus, classification  what Plato calls the “collection and division of kinds”  becomes the principal method to be used by philosophers, and this approach is most fully employed in such late works as the Sophist, Statesman, and Philebus. Presumably it contributed to Aristotle’s interest in categories and biological classification. The Republic. The moral and metaphysical theory centered on the Forms is most fully developed in the Republic, a dialogue that tries to determine whether it is in one’s own best interests to be a just person. It is commonly assumed that injustice pays if one can get away with it, and that just behavior merely serves the interests of others. Plato attempts to show that on the contrary justice, properly understood, is so great a good that it is worth any sacrifice. To support this astonishing thesis, he portrays an ideal political community: there we will see justice writ large, and so we will be better able to find justice in the individual soul. An ideal city, he argues, must make radical innovations. It should be ruled by specially trained philosophers, since their understanding of the Form of the Good will give them greater insight into everyday affairs. Their education is compared to that of a prisoner who, having once gazed upon nothing but shadows in the artificial light of a cave, is released from bondage, leaves the cave, eventually learns to see the sun, and is thereby equipped to return to the cave and see the images there for what they are. Everything in the rulers’ lives is designed to promote their allegiance to the community: they are forbidden private possessions, their sexual lives are regulated by eugenic considerations, and they are not to know who their children are. Positions of political power are open to women, since the physical differences between them and men do not in all cases deprive them of the intellectual or moral capacities needed for political office. The works of poets are to be carefully regulated, for the false moral notions of the traditional poets have had a powerful and deleterious impact on the general public. Philosophical reflection is to replace popular poetry as the force that guides moral education. What makes this city ideally just, according to Plato, is the dedication of each of its components to one task for which it is naturally suited and specially trained. The rulers are ideally equipped Plato Plato 711    711 to rule; the soldiers are best able to enforce their commands; and the economic class, composed of farmers, craftsmen, builders, and so on, are content to do their work and to leave the tasks of making and enforcing the laws to others. Accordingly what makes the soul of a human being just is the same principle: each of its components must properly perform its own task. The part of us that is capable of understanding and reasoning is the part that must rule; the assertive part that makes us capable of anger and competitive spirit must give our understanding the force it needs; and our appetites for food and sex must be trained so that they seek only those objects that reason approves. It is not enough to educate someone’s reason, for unless the emotions and appetites are properly trained they will overpower it. Just individuals are those who have fully integrated these elements of the soul. They do not unthinkingly follow a list of rules; rather, their just treatment of others flows from their own balanced psychological condition. And the paradigm of a just person is a philosopher, for reason rules when it becomes passionately attached to the most intelligible objects there are: the Forms. It emerges that justice pays because attachment to these supremely valuable objects is part of what true justice of the soul is. The worth of our lives depends on the worth of the objects to which we devote ourselves. Those who think that injustice pays assume that wealth, domination, or the pleasures of physical appetite are supremely valuable; their mistake lies in their limited conception of what sorts of objects are worth loving. Late dialogues. The Republic does not contain Plato’s last thoughts on moral or metaphysical matters. For example, although he continues to hold in his final work, the Laws, that the family and private wealth should ideally be abolished, he describes in great detail a second-best community that retains these and many other institutions of ordinary political life. The sovereignty of law in such a state is stressed continually; political offices are to be filled by elections and lots, and magistrates are subject to careful scrutiny and prosecution. Power is divided among several councils and offices, and philosophical training is not a prerequisite for political participation. This second-best state is still worlds apart from a modern liberal democracy  poetic works and many features of private life are carefully regulated, and atheism is punished with death  but it is remarkable that Plato, after having made no concessions to popular participation in the Republic, devoted so much energy to finding a proper place for it in his final work. Plato’s thoughts about metaphysics also continued to evolve, and perhaps the most serious problem in interpreting his work as a whole is the problem of grasping the direction of these further developments. One notorious obstacle to understanding his later metaphysics is presented by the Parmenides, for here we find an unanswered series of criticisms of the theory of Forms. For example, it is said that if there is reason to posit one Form of Largeness to select an arbitrary example then there is an equally good reason to posit an unlimited number of Forms of this type. The “first” Form of Largeness must exist because according to Plato whenever a number of things are large, there is a Form of Largeness that makes them large; but now, the argument continues, if we consider this Form together with the other large things, we should recognize still another Form, which makes the large things and Largeness itself large. The argument can be pursued indefinitely, but it seems absurd that there should be an unlimited number of Forms of this one type. In antiquity the argument was named the Third Man, because it claims that in addition to a second type of object called “man”  the Form of Man  there is even a third. What is Plato’s response to this and other objections to his theory? He says in the Parmenides that we must continue to affirm the existence of such objects, for language and thought require them; but instead of responding directly to the criticisms, he embarks on a prolonged examination of the concept of unity, reaching apparently conflicting conclusions about it. Whether these contradictions are merely apparent and whether this treatment of unity contains a response to the earlier critique of the Forms are difficult matters of interpretation. But in any case it is clear that Plato continues to uphold the existence of unchanging realities; the real difficulty is whether and how he modifies his earlier views about them. In the Timaeus, there seem to be no modifications at all  a fact that has led some scholars to believe, in spite of some stylometric evidence to the contrary, that this work was written before Plato composed the critique of the Forms in the Parmenides. This dialogue presents an account of how a divine but not omnipotent craftsman transformed the disorderly materials of the universe into a harmonious cosmos by looking to the unchanging Forms as paradigms and creating, to the best of his limited abilities, constantly fluctuating images of those paradigms. The crePlato Plato 712    712 ated cosmos is viewed as a single living organism governed by its own divinely intelligent soul; time itself came into existence with the cosmos, being an image of the timeless nature of the Forms; space, however, is not created by the divine craftsman but is the characterless receptacle in which all change takes place. The basic ingredients of the universe are not earth, air, fire, and water, as some thinkers held; rather, these elements are composed of planes, which are in turn made out of elementary triangular shapes. The Timaeus is an attempt to show that although many other types of objects besides the Forms must be invoked in order to understand the orderly nature of the changing universe  souls, triangles, space  the best scientific explanations will portray the physical world as a purposeful and very good approximation to a perfect pattern inherent in these unchanging and eternal objects. But Forms do not play as important a role in the Philebus, a late dialogue that contains Plato’s fullest answer to the question, What is the good? He argues that neither pleasure not intelligence can by itself be identified with the good, since no one would be satisfied with a life that contained just one of these but totally lacked the other. Instead, goodness is identified with proportion, beauty, and truth; and intelligence is ranked a superior good to pleasure because of its greater kinship to these three. Here, as in the middle dialogues, Plato insists that a proper understanding of goodness requires a metaphysical grounding. To evaluate the role of pleasure in human life, we need a methodology that applies to all other areas of understanding. More specifically, we must recognize that everything can be placed in one of four categories: the limited, the unlimited, the mixture of these two, and the intelligent creation of this mixture. Where Forms are to be located in this scheme is unclear. Although metaphysics is invoked to answer practical questions, as in the Republic, it is not precisely the same metaphysics as before. Though we naturally think of Plato primarily as a writer of philosophical works, he regards the written word as inferior to spoken interchange as an instrument for learning and teaching. The drawbacks inherent in written composition are most fully set forth in the Phaedrus. There is no doubt that in the Academy he participated fully in philosophical debate, and on at least one occasion he lectured to a general audience. We are told by Aristoxenus, a pupil of Aristotle, that many in Plato’s audience were baffled and disappointed by a lecture in which he maintained that Good is one. We can safely assume that in conversation Plato put forward important philosophical ideas that nonetheless did not find their way into his writings. Aristotle refers in Physics IV.2 to one of Plato’s doctrines as unwritten, and the enigmatic positions he ascribes to Plato in Metaphysics I.6  that the Forms are to be explained in terms of number, which are in turn generated from the One and the dyad of great and small  seem to have been expounded solely in discussion. Some scholars have put great weight on the statement in the Seventh Letter that the most fundamental philosophical matters must remain unwritten, and, using later testimony about Plato’s unwritten doctrines, they read the dialogues as signs of a more profound but hidden truth. The authenticity of the Seventh Letter is a disputed question, however. In any case, since Aristotle himself treats the middle and late dialogues as undissembling accounts of Plato’s philosophy, we are on firm ground in adopting the same approach. 

Plekhanov, Georgy Valentinovich 18561918, a leading theoretician of the Russian revolutionary movement and the father of Russian Marxism. Exiled from his native Russia for most of his adult life, in 1883 he founded in Switzerland the first Russian Marxist association  the Emancipation of Labor, a forerunner of the Russian Social Democratic Workers’ party. In philosophy he sought to systematize and disseminate the outlook of Marx and Engels, for which he popularized the name ‘dialectical materialism’. For the most part an orthodox Marxist in his understanding of history, Plekhanov argued that historical developments cannot be diverted or accelerated at will; he believed that Russia was not ready for a proletarian revolution in the first decades of the twentieth century, and consequently he opposed the Bolshevik faction in the Plato, commentaries on Plekhanov, Georgy Valentinovich 713    713 split 1903 of the Social Democratic party. At the same time he was not a simplistic economic determinist: he accepted the role of geographical, psychological, and other non-economic factors in historical change. In epistemology, Plekhanov agreed with Kant that we cannot know things in themselves, but he argued that our sensations may be conceived as “hieroglyphs,” corresponding point by point to the elements of reality without resembling them. In ethics, too, Plekhanov sought to supplement Marx with Kant, tempering the class analysis of morality with the view that there are universally binding ethical principles, such as the principle that human beings should be treated as ends rather than means. Because in these and other respects Plekhanov’s version of Marxism conflicted with Lenin’s, his philosophy was scornfully rejected by doctrinaire Marxist-Leninists during the Stalin era. 

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Plotinus A.D. 20470, Greco-Roman Neoplatonist philosopher. Born in Egypt, though doubtless of Grecian ancestry, he studied Platonic philosophy in Alexandria with Ammonius Saccas 23243; then, after a brief adventure on the staff of the Emperor Gordian III on an unsuccessful expedition against the Persians, he came to Rome in 244 and continued teaching philosophy there until his death. He enjoyed the support of many prominent people, including even the Emperor Gallienus and his wife. His chief pupils were Amelius and Porphyry, the latter of whom collected and edited his philosophical essays, the Enneads so called because arranged by Porphyry in six groups of nine. The first three groups concern the physical world and our relation to it, the fourth concerns Soul, the fifth Intelligence, and the sixth the One. Porphyry’s arrangement is generally followed today, though a chronological sequence of tractates, which he also provides in his introductory Life of Plotinus, is perhaps preferable. The most important treatises are I.1; I.2; I.6; II.4; II.8; III.23; III.6; III.7; IV.34; V.1; V.3; VI.45; VI.7; VI.8; VI.9; and the group III.8, V.8, V.5, and II.9 a single treatise, split up by Porphyry, that is a wide-ranging account of Plotinus’s philosophical position, culminating in an attack on gnosticism. Plotinus saw himself as a faithful exponent of Plato see especially Enneads V.1, but he is far more than that. Platonism had developed considerably in the five centuries that separate Plato from Plotinus, taking on much from both Aristotelianism and Stoicism, and Plotinus is the heir to this process. He also adds much himself. 

pluralism, a philosophical perspective on the world that emphasizes diversity rather than homogeneity, multiplicity rather than unity, difference rather than sameness. The philosophical consequences of pluralism were addressed by Grecian antiquity in its preoccupation with the problem of the one and the many. The proponents of pluralism, represented principally by Empedocles, Anaxagoras, and the Atomists Leucippus and Democritus, maintained that reality was made up of a multiplicity of entities. Adherence to this doctrine set them in opposition to the monism of the Eleatic School Parmenides, which taught that reality was an impermeable unity and an unbroken solidarity. It was thus that pluralism came to be defined as a philosophical alternative to monism. In the development of Occidental thought, pluralism came to be contrasted not only with monism but also with dualism, the philosophical doctrine that there are two, and only two, kinds of existents. Descartes, with his doctrine of two distinct substances  extended non-thinking substance versus non-extended thinking substance  is commonly regarded as having provided the clearest example of philosophical dualism. Pluralism thus needs to be understood as marking out philosophical alternatives to both monism and dualism. Pluralism as a metaphysical doctrine requires that we distinguish substantival from attributive pluralism. Substantival pluralism views the world as containing a multiplicity of substances that remain irreducible to each other. Attributive pluralism finds the multiplicity of kinds not among the furniture of substances that make up the world but rather among a diversity of attributes and distinguishing properties. However, pluralism came to be defined not only as a metaphysical doctrine but also as a regulative principle of explanation that calls upon differing explanatory principles and conceptual schemes to account for the manifold events of nature and the varieties of human experience. Recent philosophical thought has witnessed a resurgence of interest in pluralism. This was evident in the development of American pragmatism, where pluralism received piquant explenitude, principle of pluralism 714    714 pression in James’s A Pluralistic Universe 1909. More recently pluralism was given a voice in the thought of the later Wittgenstein, with its heavy accent on the plurality of language games displayed in our ordinary discourse. Also, in the current developments of philosophical postmodernism Jean-François Lyotard, one finds an explicit pluralistic orientation. Here the emphasis falls on the multiplicity of signifiers, phrase regimens, genres of discourse, and narrational strategies. The alleged unities and totalities of thought, discourse, and action are subverted in the interests of reclaiming the diversified and heterogeneous world of human experience. Pluralism in contemporary thought initiates a move into a postmetaphysical age. It is less concerned with traditional metaphysical and epistemological issues, seeking answers to questions about the nature and kinds of substances and attributes; and it is more attuned to the diversity of social practices and the multiple roles of language, discourse, and narrative in the panoply of human affairs. 

pluralitive logic, also called pleonetetic logic, the logic of ‘many’, ‘most’, ‘few’, and similar terms including ‘four out of five’, ‘over 45 percent’ and so on. Consider 1 ‘Almost all F are G’ 2 ‘Almost all F are not G’ 3 ‘Most F are G’ 4 ‘Most F are not G’ 5 ‘Many F are G’ 6 ‘Many F are not G’ 1 i.e., ‘Few F are not G’ and 6 are contradictory, as are 2 and 5 and 3 and 4. 1 and 2 cannot be true together i.e., they are contraries, nor can 3 and 4, while 5 and 6 cannot be false together i.e., they are subcontraries. Moreover, 1 entails 3 which entails 5, and 2 entails 4 which entails 6. Thus 16 form a generalized “square of opposition” fitting inside the standard one. Sometimes 3 is said to be true if more than half the F’s are G, but this makes ‘most’ unnecessarily precise, for ‘most’ does not literally mean ‘more than half’. Although many pluralitive terms are vague, their interrelations are logically precise. Again, one might define ‘many’ as ‘There are at least n’, for some fixed n, at least relative to context. But this not only erodes the vagueness, it also fails to work for arbitrarily large and infinite domains. ‘Few’, ‘most’, and ‘many’ are binary quantifiers, a type of generalized quantifier. A unary quantifier, such as the standard quantifiers ‘some’ and ‘all’, connotes a second-level property, e.g., ‘Something is F’ means ‘F has an instance’, and ‘All F’s are G’ means ‘F and not G has no instance’. A generalized quantifier connotes a second-level relation. ‘Most F’s are G’ connotes a binary relation between F and G, one that cannot be reduced to any property of a truth-functional compound of F and G. In fact, none of the standard pluralitive terms can be defined in first-order logic. 

plurality of causes, as used by J. S. Mill, more than one cause of a single effect; i.e., tokens of different event types causing different tokens of the same event type. Plurality of causes is distinct from overdetermination of an event by more than one actual or potential token cause. For example, an animal’s death has a plurality of causes: it may die of starvation, of bleeding, of a blow to the head, and so on. Mill thought these cases were important because he saw that the existence of a plurality of causes creates problems for his four methods for determining causes. Mill’s method of agreement is specifically vulnerable to the problem: the method fails to reveal the cause of an event when the event has more than one type of cause, because the method presumes that causes are necessary for their effects. Actually, plurality of causes is a commonplace fact about the world because very few causes are necessary for their effects. Unless the background conditions are specified in great detail, or the identity of the effect type is defined very narrowly, almost all cases involve a plurality of causes. For example, flipping the light switch is a necessary cause of the light’s going on, only if one assumes that there will be no short circuit across the switch, that the wiring will remain as it is, and so on, or if one assumes that by ‘the light’s going on’ one means the light’s going on in the normal way. 

Po-hu tung “White Tiger Hall Consultations”, an important Chinese Confucian work of the later Han dynasty, resulting from discussions at the imperial palace in A.D. 79 on the classics and their commentaries. Divided into forty-three headings, the text sums up the dominant teachings of Confucianism by affirming the absolute position of the monarch, a cosmology and moral psychology based on the yinyang theory, and a comprehensive social and political philosophy. While emphasizing benevolent government, it legitimizes the right of the ruler to use force to quell disorder. A system of “three bonds and six relationships” defines the hierarchical structure of society. Human nature, identified with the yang cosmic force, must be cultivated, while feelings yin are to be controlled especially by rituals and education. The Confucian orthodoxy affirmed also marks an end to the debate between the Old Text school and the New Text school that divided earlier Han scholars. 

poiesis Grecian, ‘production’, behavior aimed at an external end. In Aristotle, poiesis is opposed to praxis action. It is characteristic of crafts  e.g. building, the end of which is houses. It is thus a kinesis process. For Aristotle, exercising the virtues, since it must be undertaken for its own sake, cannot be poiesis. The knowledge involved in virtue is therefore not the same as that involved in crafts. R.C. Poincaré, Jules Henri 18541912, French mathematician and influential philosopher of science. Born into a prominent family in Nancy, he showed extraordinary talent in mathematics from an early age. He studied at the École des Mines and worked as a mining engineer while completing his doctorate in mathematics 1879. In 1881, he was appointed professor at the  of Paris, where he lectured on mathematics, physics, and astronomy until his death. His original contributions to the theory of differential equations, algebraic topology, and number theory made him the leading mathematician of his day. He published almost five hundred technical papers as well as three widely read books on the philosophy of science: Science and Hypothesis 1902, The Value of Science 1905, and Science and Method 1908. Poincaré’s philosophy of science was shaped by his approach to mathematics. Geometric axioms are neither synthetic a priori nor empirical; they are more properly understood as definitions. Thus, when one set of axioms is preferred over another for use in physics, the choice is a matter of “convention”; it is governed by criteria of simplicity and economy of expression rather than by which geometry is “correct.” Though Euclidean geometry is used to describe the motions of bodies in space, it makes no sense to ask whether physical space “really” is Euclidean. Discovery in mathematics resembles discovery in the physical sciences, but whereas the former is a construction of the human mind, the latter has to be fitted to an order of nature that is ultimately independent of mind. Science provides an economic and fruitful way of expressing the relationships between classes of sensations, enabling reliable predictions to be made. These sensations reflect the world that causes them; the limited objectivity of science derives from this fact, but science does not purport to determine the nature of that underlying world. Conventions, choices that are not determinable by rule, enter into the physical sciences at all levels. Such principles as that of the conservation of energy may appear to be empirical, but are in fact postulates that scientists have chosen to treat as implicit definitions. The decision between alternative hypotheses also involves an element of convention: the choice of a particular curve to represent a finite set of data points, e.g., requires a judgment as to which is simpler. Two kinds of hypotheses, in particular, must be distinguished. Inductive generalizations from observation “real generalizations” are hypothetical in the limited sense that they are always capable of further precision. Then there are theories “indifferent hypotheses” that postulate underlying entities or structures. These entities may seem explanatory, but strictly speaking are no more than devices useful in calculation. For atomic theory to explain, atoms would have to exist. But this cannot be established in the only way permissible for a scientific claim, i.e. directly by experiment. Shortly before he died, Poincaré finally allowed that Perrin’s experimental verification of Einstein’s predictions regarding Brownian motion, plus his careful marshaling of twelve other distinct experimental methods of calculating Avogadro’s number, constituted the equivalent of an experimental proof of the existence of atoms: “One can say that we see them because we can count them. . . . The atom of the chemist is now a reality.”

 polarity, the relation between distinct phenomena, terms, or concepts such that each inextricably requires, though it is opposed to, the other, as in the relation between the north and south poles of a magnet. In application to terms or concepts, polarity entails that the meaning of one involves the meaning of the other. This is conceptual polarity. Terms are existentially polar provided an instance of one cannot exist unless there exists an instance of the other. The second sense implies the first. Supply and demand and good and evil are instances of conceptual polarity. North and south and buying and selling are instances of existential polarity. Some polar concepts are opposites, such as truth and falsity. Some are correlative, such as question and answer: an answer is always an answer to a question; a question calls for an answer, but a question can be an answer, and an answer can be a question. The concept is not restricted to pairs and can be extended to generate mutual interdependence, multipolarity.

Polish logic, logic as researched, elucidated, and taught in Poland, 191939. Between the two wars colleagues Jan Lukasiewicz, Tadeusz Kotarbigki, and Stanislaw Lesniewski, assisted by students-become-collaborators such as Alfred Tarski, Jerzy Slupecki, Stanislaw Jaskowski, and Boleslaw Sobocigski, together with mathematicians in Warsaw and philosophical colleagues elsewhere, like Kasimir Ajdukiewicz and Tadeusz Czezowski, made Warsaw an internationally known center of research in logic, metalogic, semantics, and foundations of mathematics. The Warsaw “school” also dominated Polish philosophy, and made Poland the country that introduced modern logic even in secondary schools. All three founders took their doctorates in Lvov under Kasimir Twardowski 18661938, mentor of leading thinkers of independent Poland between the wars. Arriving from Vienna to take the chair of philosophy at twenty-nine, Twardowski had to choose between concentrating on his own research and organizing the study of philosophy in Poland. Dedicating his life primarily to the community task, he became the founder of modern Polish philosophy. Twardowski’s informal distinction between distributive and collective conceptions influenced classification of philosophy and the sciences, and anticipated Lesniewski’s formal axiomatizations in ontology and mereology, respectively. Another common inheritance important in Polish logic was Twardowski’s stress on the processproduct ambiguity. He applied this distinction to disambiguate ‘meaning’ and refine his teacher Brentano’s account of mental acts as meaningful “intentional” events, by differentiating 1 what is meant or “intended” by the act, its objective noema or noematic “intentional object,” from 2 its corresponding noetic meaning or subjective “content,” the correlated characteristic or structure by which it “intends” its “object” or “objective”  i.e., means that: suchand-such is so. Twardowski’s teaching  especially this careful analysis of “contents” and “objects” of mental acts  contributed to Meinong’s theory of objects, and linked it, Husserl’s phenomenology, and Anton Marty’s “philosophical grammar” with the “descriptive psychology” of their common teacher, the Aristotelian and Scholastic empiricist Brentano, and thus with sources of the analytic movements in Vienna and Cambridge. Twardowski’s lectures on the philosophical logic of content and judgment prepared the ground for scientific semantics; his references to Boolean algebra opened the door to mathematical logic; and his phenomenological idea of a general theory of objects pointed toward Lesniewski’s ontology. Twardowski’s maieutic character, integrity, grounding in philosophical traditions, and arduous training lectures began at six a.m., together with his realist defense of the classical Aristotelian correspondence theory of truth against “irrationalism,” dogmatism, skepticism, and psychologism, influenced his many pupils, who became leaders of Polish thought in diverse fields. But more influential than any doctrine was his rigorist ideal of philosophy as a strict scientific discipline of criticism and logical analysis, precise definition, and conceptual clarification. His was a school not of doctrine but of method. Maintaining this common methodological inheritance in their divergent ways, and encouraged to learn more mathematical logic than Twardowski himself knew, his students in logic were early influenced by Frege’s and Husserl’s critique of psychologism in logic, Husserl’s logical investigations, and the logical reconstruction of classical mathematics by Frege, Schröder, Whitehead, and Russell. As lecturer in Lvov from 1908 until his appointment to Warsaw in 1915, Lukasiewicz introduced mathematical logic into Poland. To Lesniewski, newly arrived from studies in Germany as an enthusiast for Marty’s philosophy of language, Lukasiewicz’s influential 1910 Critique of Aristotle’s principle of contradiction was a “revelation” in 1911. Among other things it    717 Polish notation political philosophy 718 revealed paradoxes like Russell’s, which preoccupied him for the next eleven years as, logically refuting Twardowski’s Platonist theory of abstraction, he worked out his own solutions and, influenced also by Leon Chwistek, outgrew the influence of Hans Cornelius and Leon Petraz´ycki, and developed his own “constructively nominalist” foundations. In 1919 Kotarbisski and Lesniewski joined Lukasiewicz in Warsaw, where they attracted students like Tarski, Sobocigski, and Slupecki in the first generation, and Andrzej Mostowski and Czeslaw Lejewski in the next. When the war came, the survivors were scattered and the metalogicians Morchaj Wajsberg, Moritz Presburger, and Adolf Lindenbaum were killed or “disappeared” by the Gestapo. Lukasiewicz concentrated increasingly on history of logic especially in reconstructing the logic of Aristotle and the Stoics and deductive problems concerning syllogistic and propositional logic. His idea of logical probability and development of three- or manyvalued and modal calculi reflected his indeterminist sympathies in prewar exchanges with Kotarbigski and Lesniewski on the status of truths eternal, sempiternal, or both?, especially as concerns future contingencies. Lesniewski concentrated on developing his logical systems. He left elaboration of many of his seminal metalogical and semantic insights to Tarski, who, despite a divergent inclination to simplify metamathematical deductions by expedient postulation, shared with Lesniewski, Lukasiewicz, and Ajdukiewicz the conviction that only formalized languages can be made logically consistent subjects and instruments of rigorous scientific investigation. Kotarbigski drew on Lesniewski’s logic of predication to defend his “reism” as one possible application of Lesniewski’s ontology, to facilitate his “concretist” program for translating abstractions into more concrete terms, and to rationalize his “imitationist” account of mental acts or dispositions. Inheriting Twardowski’s role as cultural leader and educator, Kotarbigski popularized the logical achievements of his colleagues in e.g. his substantial 1929 treatise on the theory of knowledge, formal logic, and scientific methodology; this work became required reading for serious students and, together with the lucid textbooks by Lukasiewicz and Ajdukiewicz, raised the level of philosophical discussion in Poland. Jaskowski published a system of “natural deduction” by the suppositional method practiced by Lesniewski since 1916. Ajdukiewicz based his syntax on Lesniewski’s logical grammar, and by his searching critiques influenced Kotarbigski’s “reist” and “concretist” formulations. Closest in Poland to the logical positivists of the Vienna Circle, Ajdukiewicz brought new sophistication to the philosophy of language and of science by his examination of the role of conventions and meaning postulates in scientific theory and language, distinguishing axiomatic, deductive, and empirical rules of meaning. His evolving and refined conventionalist analyses of theories, languages, “world perspectives,” synonymy, translation, and analyticity, and his philosophical clarification by paraphrase anticipated views of Carnap, Feigl, and Quine. But the Polish thinkers, beyond their common methodological inheritance and general adherence to extensional logic, subscribed to little common doctrine, and in their exchanges with the Vienna positivists remained “too sober” said Lukasiewicz to join in sweeping antimetaphysical manifestos. Like Twardowski, they were critics of traditional formulations, who sought not to proscribe but to reform metaphysics, by reformulating issues clearly enough to advance understanding. Indeed, except for Chwistek, the mathematician Jan Slezygski, and the historians I. M. Bochegski, Z. A. Jordan, and Jan Salamucha, in addition to the phenomenologist Roman Ingarden, the key figures in Polish logic were all philosophical descendants of Twardowski. 

political philosophy, the study of the nature and justification of coercive institutions. Coercive institutions range in size from the family to the nation-state and world organizations like the United Nations. They are institutions that at least sometimes employ force or the threat of force to control the behavior of their members. Justifying such coercive institutions requires showing that the authorities within them have a right to be obeyed and that their members have a corresponding obligation to obey them, i.e., that these institutions have legitimate political authority over their members. Classical political philosophers, like Plato and Aristotle, were primarily interested in providing a justification for city-states like Athens or Sparta. But historically, as larger coercive insti   718 tutions became possible and desirable, political philosophers sought to justify them. After the seventeenth century, most political philosophers focused on providing a justification for nationstates whose claim to legitimate authority is restricted by both geography and nationality. But from time to time, and more frequently in the nineteenth and twentieth centuries, some political philosophers have sought to provide a justification for various forms of world government with even more extensive powers than those presently exercised by the United Nations. And quite recently, feminist political philosophers have raised important challenges to the authority of the family as it is presently constituted. Anarchism from Grecian an archos, ‘no government’ rejects this central task of political philosophy. It maintains that no coercive institutions are justified. Proudhon, the first self-described anarchist, believed that coercive institutions should be replaced by social and economic organizations based on voluntary contractual agreement, and he advocated peaceful change toward anarchism. Others, notably Blanqui and Bakunin, advocated the use of violence to destroy the power of coercive institutions. Anarchism inspired the anarcho-syndicalist movement, Makhno and his followers during the Russian Civil War, the Spanish anarchists during the Spanish Civil War, and the anarchist gauchistes during the 1968 “May Events” in France. Most political philosophers, however, have sought to justify coercive institutions; they have simply disagreed over what sort of coercive institutions are justified. Liberalism, which derives from the work of Locke, is the view that coercive institutions are justified when they promote liberty. For Locke, liberty requires a constitutional monarchy with parliamentary government. Over time, however, the ideal of liberty became subject to at least two interpretations. The view that seems closest to Locke’s is classical liberalism, which is now more frequently called political libertarianism. This form of liberalism interprets constraints on liberty as positive acts i.e., acts of commission that prevent people from doing what they otherwise could do. According to this view, failing to help people in need does not restrict their liberty. Libertarians maintain that when liberty is so interpreted only a minimal or night-watchman state that protects against force, theft, and fraud can be justified. In contrast, in welfare liberalism, a form of liberalism that derives from the work of T. H. Green, constraints on liberty are interpreted to include, in addition, negative acts i.e., acts of omission that prevent people from doing what they otherwise could do. According to this view, failing to help people in need does restrict their liberty. Welfare liberals maintain that when liberty is interpreted in this fashion, coercive institutions of a welfare state requiring a guaranteed social minimum and equal opportunity are justified. While no one denies that when liberty is given a welfare liberal interpretation some form of welfare state is required, there is considerable debate over whether a minimal state is required when liberty is given a libertarian interpretation. At issue is whether the liberty of the poor is constrained when they are prevented from taking from the surplus possessions of the rich what they need for survival. If such prevention does constrain the liberty of the poor, it could be argued that their liberty should have priority over the liberty of the rich not to be interfered with when using their surplus possessions for luxury purposes. In this way, it could be shown that even when the ideal of liberty is given a libertarian interpretation, a welfare state, rather than a minimal state, is justified. Both libertarianism and welfare liberalism are committed to individualism. This view takes the rights of individuals to be basic and justifies the actions of coercive institutions as promoting those rights. Communitarianism, which derives from the writings of Hegel, rejects individualism. It maintains that rights of individuals are not basic and that the collective can have rights that are independent of and even opposed to what liberals claim are the rights of individuals. According to communitarians, individuals are constituted by the institutions and practices of which they are a part, and their rights and obligations derive from those same institutions and practices. Fascism is an extreme form of communitarianism that advocates an authoritarian state with limited rights for individuals. In its National Socialism Nazi variety, fascism was also antiSemitic and militarist. In contrast to liberalism and communitarianism, socialism takes equality to be the basic ideal and justifies coercive institutions insofar as they promote equality. In capitalist societies where the means of production are owned and controlled by a relatively small number of people and used primarily for their benefit, socialists favor taking control of the means of production and redirecting their use to the general welfare. According to Marx, the principle of distribution for a socialist society is: from each according to political philosophy political philosophy 719    719 ability, to each according to needs. Socialists disagree among themselves, however, over who should control the means of production in a socialist society. In the version of socialism favored by Lenin, those who control the means of production are to be an elite seemingly differing only in their ends from the capitalist elite they replaced. In other forms of socialism, the means of production are to be controlled democratically. In advanced capitalist societies, national defense, police and fire protection, income redistribution, and environmental protection are already under democratic control. Democracy or “government by the people” is thought to apply in these areas, and to require some form of representation. Socialists simply propose to extend the domain of democratic control to include control of the means of production, on the ground that the very same arguments that support democratic control in these recognized areas also support democratic control of the means of production. In addition, according to Marx, socialism will transform itself into communism when most of the work that people perform in society becomes its own reward, making differential monetary reward generally unnecessary. Then distribution in society can proceed according to the principle, from each according to ability, to each according to needs. It so happens that all of the above political views have been interpreted in ways that deny that women have the same basic rights as men. By contrast, feminism, almost by definition, is the political view that women and men have the same basic rights. In recent years, most political philosophers have come to endorse equal basic rights for women and men, but rarely do they address questions that feminists consider of the utmost importance, e.g., how responsibilities and duties are to be assigned in family structures. Each of these political views must be evaluated both internally and externally by comparison with the other views. Once this is done, their practical recommendations may not be so different. For example, if welfare liberals recognize that the basic rights of their view extend to distant peoples and future generations, they may end up endorsing the same degree of equality socialists defend. Whatever their practical requirements, each of these political views justifies civil disobedience, even revolution, when certain of those requirements have not been met. Civil disobedience is an illegal action undertaken to draw attention to a failure by the relevant authorities to meet basic moral requirements, e.g., the refusal of Rosa Parks to give up her seat in a bus to a white man in accord with the local ordinance in Montgomery, Alabama, in 1955. Civil disobedience is justified when illegal action of this sort is the best way to get the relevant authorities to bring the law into better correspondence with basic moral requirements. By contrast, revolutionary action is justified when it is the only way to correct a radical failure of the relevant authorities to meet basic moral requirements. When revolutionary action is justified, people no longer have a political obligation to obey the relevant authorities; that is, they are no longer morally required to obey them, although they may still continue to do so, e.g. out of habit or fear. Recent contemporary political philosophy has focused on the communitarianliberal debate. In defense of the communitarian view, Alasdair MacIntyre has argued that virtually all forms of liberalism attempt to separate rules defining right action from conceptions of the human good. On this account, he contends, these forms of liberalism must fail because the rules defining right action cannot be adequately grounded apart from a conception of the good. Responding to this type of criticism, some liberals have openly conceded that their view is not grounded independently of some conception of the good. Rawls, e.g., has recently made clear that his liberalism requires a conception of the political good, although not a comprehensive conception of the good. It would seem, therefore, that the debate between communitarians and liberals must turn on a comparative evaluation of their competing conceptions of the good. Unfortunately, contemporary communitarians have not yet been very forthcoming about what particular conception of the good their view requires. 

political theory, reflection concerning the empirical, normative, and conceptual dimensions of political life. There are no topics that all political theorists do or ought to address, no required procedures, no doctrines acknowledged to be authoritative. The meaning of ‘political theory’ resides in its fluctuating uses, not in any essential property. It is nevertheless possible to identify concerted tendencies among those who have practiced this activity over twenty-five centuries. Since approximately the seventeenth century, a primary question has been how best to justify political theory political theory 720    720 the political rule of some people over others. This question subordinated the issue that had directed and organized most previous political theory, namely, what constitutes the best form of political regime. Assuming political association to be a divinely ordained or naturally necessary feature of the human estate, earlier thinkers had asked what mode of political association contributes most to realizing the good for humankind. Signaling the variable but intimate relationship between political theory and political practice, the change in question reflected and helped to consolidate acceptance of the postulate of natural human equality, the denial of divinely or naturally given authority of some human beings over others. Only a small minority of postseventeenth-century thinkers have entertained the possibility, perhaps suggested by this postulate, that no form of rule can be justified, but the shift in question altered the political theory agenda. Issues concerning consent, individual liberties and rights, various forms of equality as integral to justice, democratic and other controls on the authority and power of government  none of which were among the first concerns of ancient or medieval political thinkers  moved to the center of political theory. Recurrent tendencies and tensions in political theory may also be discerned along dimensions that cross-cut historical divisions. In its most celebrated representations, political theory is integral to philosophy. Systematic thinkers such as Plato and Aristotle, Augustine and Aquinas, Hobbes and Hegel, present their political thoughts as supporting and supported by their ethics and theology, metaphysics and epistemology. Political argumentation must satisfy the same criteria of logic, truth, and justification as any other; a political doctrine must be grounded in the nature of reality. Other political theorists align themselves with empirical science rather than philosophy. Often focusing on questions of power, they aim to give accurate accounts and factually grounded assessments of government and politics in particular times and places. Books IVVI of Aristotle’s Politics inaugurate this conception of political theory; it is represented by Montesquieu, Marx, and much of utilitarianism, and it is the numerically predominant form of academic political theorizing in the twentieth century. Yet others, e.g., Socrates, Machiavelli, Rousseau, and twentieth-century thinkers such as Rawls, mix the previously mentioned modes but understand themselves as primarily pursuing the practical objective of improving their own political societies.

polysyllogism, a series of syllogisms connected by the fact that the conclusion of one syllogism becomes a premise of another. The syllogism whose conclusion is used as a premise in another syllogism within the chain is called the prosyllogism; the syllogism is which the conclusion of another syllogism within the chain is used as a premise is called the episyllogism. To illustrate, take the standard form of the simplest polysyllogism: a 1 Every B is A 2 Every C is B 3 , Every C is A b 4 Every C is A 5 Every D is C 6 , Every D is A. The first member a of this polysyllogism is the prosyllogism, since its conclusion, 3, occurs as a premise, 4, in the second argument. This second member, b, is the episyllogism, since it employs as one of its premises 4 the conclusion 3 of the first syllogism. It should be noted that the terms ‘prosyllogism’ and ‘episyllogism’ are correlative terms. Moreover, a polysyllogism may have more than two members. 

Pomponazzi, Pietro 14621525, Italian philosopher, an Aristotelian who taught at the universities of Padua and Bologna. In De incantationibus “On Incantations,” 1556, he regards the world as a system of natural causes that can explain apparently miraculous phenomena. Human beings are subject to the natural order of the world, yet divine predestination and human freedom are compatible De fato, “On Fate,” 1567. Furthermore, he distinguishes between what is proved by natural reason and what is accepted by faith, and claims that, since there are arguments for and against the immortality of the human individual soul, this belief is to be accepted solely on the basis of faith De immortalitate animae, “On the Immortality of the Soul,” polyadic Pomponazzi, Pietro 721    721 1516. He defended his view of immortality in the Apologia 1518 and in the Defensorium 1519. These three works were reprinted as Tractatus acutissimi 1525. Pomponazzi’s work was influential until the seventeenth century, when Aristotelianism ceased to be the main philosophy taught at the universities. The eighteenth-century freethinkers showed new interest in his distinction between natural reason and faith. P.Gar. pons asinorum Latin, ‘asses’ bridge’, a methodological device based upon Aristotle’s description of the ways in which one finds a suitable middle term to demonstrate categorical propositions. Thus, to prove the universal affirmative, one should consider the characters that entail the predicate P and the characters entailed by the subject S. If we find in the two groups of characters a common member, we can use it as a middle term in the syllogistic proof of say ‘All S are P’. Take ‘All men are mortal’ as the contemplated conclusion. We find that ‘organism’ is among the characters entailing the predicate ‘mortal’ and is also found in the group of characters entailed by the subject ‘men’, and thus it may be used in a syllogistic proof of ‘All men are mortal’. To prove negative propositions we must, in addition, consider characters incompatible with the predicate, or incompatible with the subject. Finally, proofs of particular propositions require considering characters that entail the subject. 

Popper, Karl Raimund 190294, Austrian-born British philosopher best known for contributions to philosophy of science and to social and political philosophy. Educated at the  of Vienna Ph.D., 1928, he taught philosophy in New Zealand for a decade before becoming a reader and then professor in logic and scientific method at the London School of Economics 194669. He was knighted in 1965, elected a fellow of the Royal Society in 1976, and appointed Companion of Honour in 1982 see his autobiography, Unended Quest, 1976. In opposition to logical positivism’s verifiability criterion of cognitive significance, Popper proposes that science be characterized by its method: the criterion of demarcation of empirical science from pseudo-science and metaphysics is falsifiability Logik der Forschung, 1934, translated as The Logic of Scientific Discovery, 1959. According to falsificationism, science grows, and may even approach the truth, not by amassing supporting evidence, but through an unending cycle of problems, tentative solutions  unjustifiable conjectures  and error elimination; i.e., the vigorous testing of deductive consequences and the refutation of conjectures that fail Conjectures and Refutations, 1963. Since conjectures are not inferences and refutations are not inductive, there is no inductive inference or inductive logic. More generally, criticism is installed as the hallmark of rationality, and the traditional justificationist insistence on proof, conclusive or inconclusive, on confirmation, and on positive argument, is repudiated. Popper brings to the central problems of Kant’s philosophy an uncompromising realism and objectivism, the tools of modern logic, and a Darwinian perspective on knowledge, thereby solving Hume’s problem of induction without lapsing into irrationalism Objective Knowledge, 1972. He made contributions of permanent importance also to the axiomatization of probability theory The Logic of Scientific Discovery, 1959; to its interpretation, especially the propensity interpretation Postscript to The Logic of Scientific Discovery, 3 vols. 198283; and to many other problems The Self and Its Brain, with John C. Eccles, 1977. Popper’s social philosophy, like his epistemology, is anti-authoritarian. Since it is a historicist error to suppose that we can predict the future of mankind The Poverty of Historicism, 1957, the prime task of social institutions in an open society  one that encourages criticism and allows rulers to be replaced without violence  must be not large-scale utopian planning but the minimization, through piecemeal reform, of avoidable suffering. This way alone permits proper assessment of success or failure, and thus of learning from experience The Open Society and Its Enemies, 1945. 

Porphyry c.232c.304, Grecian Neoplatonist philosopher, second to Plotinus in influence. He was born in Tyre, and is thus sometimes called Porphyry the Phoenician. As a young man he went to Athens, where he absorbed the Platonism of Cassius Longinus, who had in turn been influenced by Ammonius Saccas in Alexandria. Porphyry went to Rome in 263, where he became a disciple of Plotinus, who had also been influenced by Ammonius. Porphyry lived in Rome until 269, when, urged by Plotinus to pons asinorum Porphyry 722    722 travel as a cure for severe depression, he traveled to Sicily. He remained there for several years before returning to Rome to take over Plotinus’s school. He apparently died in Rome. Porphyry is not noted for original thought. He seems to have dedicated himself to explicating Aristotle’s logic and defending Plotinus’s version of Neoplatonism. During his years in Sicily, Porphyry wrote his two most famous works, the lengthy Against the Christians, of which only fragments survive, and the Isagoge, or “Introduction.” The Isagoge, which purports to give an elementary exposition of the concepts necessary to understand Aristotle’s Categories, was translated into Latin by Boethius and routinely published in the Middle Ages with Latin editions of Aristotle’s Organon, or logical treatises. Its inclusion in that format arguably precipitated the discussion of the so-called problem of universals in the twelfth century. During his later years in Rome, Porphyry collected Plotinus’s writings, editing and organizing them into a scheme of his own  not Plotinus’s  design, six groups of nine treatises, thus called the Enneads. Porphyry prefaced his edition with an informative biography of Plotinus, written shortly before Porphyry’s own death. 

Port-Royal Logic, originally entitled La logique, ou L’art de penser, a treatise on logic, language, and method composed by Antoine Arnauld and Pierre Nicole 162595, possibly with the help of Pascal, all of whom were solitaires associated with the convent at Port-Royal-des-Champs, the spiritual and intellectual center of French Jansenism. Originally written as an instruction manual for the son of the Duc de Luynes, the Logic was soon expanded and published the first edition appeared in 1662, but it was constantly being modified, augmented, and rewritten by its authors; by 1685 six editions in French had appeared. The work develops the linguistic theories presented by Arnauld and Claude Lancelot in the Grammaire générale et raisonnée 1660, and reflects the pedagogical principles embodied in the curriculum of the “little schools” run by PortRoyal. Its content is also permeated by the Cartesianism to which Arnauld was devoted. The Logic’s influence grew beyond Jansenist circles, and it soon became in seventeenth-century France a standard manual for rigorous thinking. Eventually, it was adopted as a textbook in French schools. The authors declare their goal to be to make thought more precise for better distinguishing truth from error  philosophical and theological  and to develop sound judgment. They are especially concerned to dispel the errors and confusions of the Scholastics. Logic is “the art of directing reason to a knowledge of things for the instruction of ourselves and others.” This art consists in reflecting on the mind’s four principal operations: conceiving, judging, reasoning, and ordering. Accordingly, the Logic is divided into four sections: on ideas and conception, on judgments, on reasoning, and on method..

positive and negative freedom, respectively, the area within which the individual is self-determining and the area within which the individual is left free from interference by others. More specifically, one is free in the positive sense to the extent that one has control over one’s life, or rules oneself. In this sense the term is very close to that of ‘autonomy’. The forces that can prevent this self-determination are usually thought of as internal, as desires or passions. This conception of freedom can be said to have originated with Plato, according to whom a person is free when the parts of the soul are rightly related to each other, i.e. the rational part of the soul rules the other parts. Other advocates of positive freedom include Spinoza, Rousseau, Kant, and Hegel. One is free in the negative sense if one is not prevented from doing something by another person. One is prevented from doing something if another person makes it impossible for one to do something or uses coercion to prevent one from doing something. Hence persons are free in the negative sense if they are not made unfree in the negative sense. The term ‘negative liberty’ was coined by Bentham to mean the absence of coercion. Advocates of negative freedom include Hobbes, Locke, and Hume. 

possible worlds, alternative worlds in terms of which one may think of possibility. The idea of thinking about possibility in terms of such worlds has played an important part, both in Leibnizian philosophical theology and in the development of modal logic and philosophical reflection about it in recent decades. But there are important differences in the forms the idea has taken, and the uses to which it has been put, in the two contexts. Leibniz used it in his account of creation. In his view God’s mind necessarily and eternally contains the ideas of infinitely many worlds that God could have created, and God has chosen the best of these and made it actual, thus creating it. Similar views are found in the thought of Leibniz’s contemporary, Malebranche. The possible worlds are thus the complete alternatives among which God chose. They are possible at least in the sense that they are logically consistent; whether something more is required in order for them to be coherent as worlds is a difficult question in Leibniz interpretation. They are complete in that they are possible totalities of creatures; each includes a whole possible universe, in its whole spatial extent and its whole temporal history if it is spatially and temporally ordered. The temporal completeness deserves emphasis. If “the world of tomorrow” is “a better world” than “the world of today,” it will still be part of the same “possible world” the actual one; for the actual “world,” in the relevant sense, includes whatever actually has happened or will happen throughout all time. The completeness extends to every detail, so that a milligram’s difference in the weight of the smallest bird would make a different possible world. The completeness of possible worlds may be limited in one way, however. Leibniz speaks of worlds as aggregates of finite things. As alternatives for God’s creation, they may well not be thought of as including God, or at any rate, not every fact about God. For this and other reasons it is not clear that in Leibniz’s thought the possible can be identified with what is true in some possible world, or the necessary with what is true in all possible worlds. That identification is regularly assumed, however, in the recent development of what has become known as possible worlds semantics for modal logic the logic of possibility and necessity, and of other conceptions, e.g. those pertaining to time and to morality, that have turned out to be formally analogous. The basic idea here is that such notions as those of validity, soundness, and completeness can be defined for modal logic in terms of models constructed from sets of alternative “worlds.” Since the late 1950s many important results have been obtained by this method, whose best-known exponent is Saul Kripke. Some of the most interesting proofs depend on the idea of a relation of accessibility between worlds in the set. Intuitively, one world is accessible from another if and only if the former is possible in or from the point of view of the latter. Different systems of modal logic are appropriate depending on the properties of this relation e.g., on whether it is or is not reflexive and/or transitive and/or symmetrical. The purely formal results of these methods are well established. The application of possible worlds semantics to conceptions occurring in metaphysically richer discourse is more controversial, however. Some of the controversy is related to debates over the metaphysical reality of various sorts of possibility and necessity. Particularly controversial, and also a focus of much interest, have been attempts to understand modal claims de re, about particular individuals as such e.g., that I could not have been a musical performance, in terms of the identity and nonidentity of individuals in different possible worlds. Similarly, there is debate over the applicability of a related treatment of subjunctive conditionals, developed by Robert Stalnaker and David Lewis, though it is clear that it yields interesting formal results. What is required, on this approach, for the truth of ‘If it were the case that A, then it would be the case that B’, is that, among those possible worlds in which A is true, some world in which B is true be more similar, in the relevant respects, to the actual world than any world in which B is false. One of the most controversial topics is the nature of possible worlds themselves. Mathematical logicians need not be concerned with this; a wide variety of sets of objects, real or ficpositive morality possible worlds 724    724 titious, can be viewed as having the properties required of sets of “worlds” for their purposes. But if metaphysically robust issues of modality e.g., whether there are more possible colors than we ever see are to be understood in terms of possible worlds, the question of the nature of the worlds must be taken seriously. Some philosophers would deny any serious metaphysical role to the notion of possible worlds. At the other extreme, David Lewis has defended a view of possible worlds as concrete totalities, things of the same sort as the whole actual universe, made up of entities like planets, persons, and so forth. On his view, the actuality of the actual world consists only in its being this one, the one that we are in; apart from its relation to us or our linguistic acts, the actual is not metaphysically distinguished from the merely possible. Many philosophers find this result counterintuitive, and the infinity of concrete possible worlds an extravagant ontology; but Lewis argues that his view makes possible attractive reductions of modality both logical and causal, and of such notions as that of a proposition, to more concrete notions. Other philosophers are prepared to say there are non-actual possible worlds, but that they are entities of a quite different sort from the actual concrete universe  sets of propositions, perhaps, or some other type of “abstract” object. Leibniz himself held a view of this kind, thinking of possible worlds as having their being only in God’s mind, as intentional objects of God’s thought. 

postmodern, of or relating to a complex set of reactions to modern philosophy and its presuppositions, as opposed to the kind of agreement on substantive doctrines or philosophical questions that often characterizes a philosophical movement. Although there is little agreement on precisely what the presuppositions of modern philosophy are, and disagreement on which philosophers exemplify these presuppositions, postmodern philosophy typically opposes foundationalism, essentialism, and realism. For Rorty, e.g., the presuppositions to be set aside are foundationalist assumptions shared by the leading sixteenth-, seventeenth-, and eighteenth-century philosophers. For Nietzsche, Heidegger, Foucault, and Derrida, the contested presuppositions to be set aside are as old as metaphysics itself, and are perhaps best exemplified by Plato. Postmodern philosophy has even been characterized, by Lyotard, as preceding modern philosophy, in the sense that the presuppositions of philosophical modernism emerge out of a disposition whose antecedent, unarticulated beliefs are already postmodern. Postmodern philosophy is therefore usefully regarded as a complex cluster concept that includes the following elements: an anti- or post- epistemological standpoint; anti-essentialism; anti-realism; anti-foundationalism; opposition to transcendental arguments and transcendental standpoints; rejection of the picture of knowledge as accurate representation; rejection of truth as correspondence to reality; rejection of the very idea of canonical descriptions; rejection of final vocabularies, i.e., rejection of principles, distinctions, and descriptions that are thought to be unconditionally binding for all times, persons, and places; and a suspicion of grand narratives, metanarratives of the sort perhaps best illustrated by dialectical materialism. In addition to these things postmodern philosophy is “against,” it also opposes characterizing this menu of oppositions as relativism, skepticism, or nihilism, and it rejects as “the metaphysics of presence” the traditional, putatively impossible dream of a complete, unique, and closed explanatory system, an explanatory system typically fueled by binary oppositions. On the positive side, one often finds the following themes: its critique of the notion of the neutrality and sovereignty of reason  including insistence on its pervasively gendered, historical, and ethnocentric character; its conception of the social construction of wordworld mappings; its tendency to embrace historicism; its critique of the ultimate status of a contrast between epistemology, on the one hand, and the sociology of knowledge, on the other hand; its dissolution of the notion of the autonomous, rational subject; its insistence on the artifactual status of divisions of labor in knowledge acquisition and production; and its ambivalence about the Enlightenment and its ideology. Many of these elements or elective affinities were already surfacing in the growing opposition to the spectator theory of knowledge, in Europe and in the English-speaking world, long before possible worlds semantics postmodern 725    725 the term ‘postmodern’ became a commonplace. In Anglophone philosophy this took the early form of Dewey’s and pragmatism’s opposition to positivism, early Kuhn’s redescription of scientific practice, and Wittgenstein’s insistence on the language-game character of representation; critiques of “the myth of the given” from Sellars to Davidson and Quine; the emergence of epistemology naturalized; and the putative description-dependent character of data, tethered to the theory dependence of descriptions in Kuhn, Sellars, Quine, and Arthur Fine  perhaps in all constructivists in the philosophy of science. In Europe, many of these elective affinities surfaced explicitly in and were identified with poststructuralism, although traces are clearly evident in Heidegger’s and later in Derrida’s attacks on Husserl’s residual Cartesianism; the rejection of essential descriptions Wesensanschauungen in Husserl’s sense; Saussure’s and structuralism’s attack on the autonomy and coherence of a transcendental signified standing over against a selftransparent subject; Derrida’s deconstructing the metaphysics of presence; Foucault’s redescriptions of epistemes; the convergence between French- and English-speaking social constructivists; attacks on the language of enabling conditions as reflected in worries about the purchase of necessary and sufficient conditions talk on both sides of the Atlantic; and Lyotard’s many interventions, particularly those against grand narratives. Many of these elective affinities that characterize postmodern philosophy can also be seen in the virtually universal challenges to moral philosophy as it has been understood traditionally in the West, not only in German and French philosophy, but in the reevaluation of “the morality of principles” in the work of MacIntyre, Williams, Nussbaum, John McDowell, and others. The force of postmodern critiques can perhaps best be seen in some of the challenges of feminist theory, as in the work of Judith Butler and Hélène Cixous, and gender theory generally. For it is in gender theory that the conception of “reason” itself as it has functioned in the shared philosophical tradition is redescribed as a conception that, it is often argued, is engendered, patriarchal, homophobic, and deeply optional. The term ‘postmodern’ is less clear in philosophy, its application more uncertain and divided than in some other fields, e.g., postmodern architecture. In architecture the concept is relatively clear. It displaces modernism in assignable ways, emerges as an oppositional force against architectural modernism, a rejection of the work and tradition inaugurated by Walter Gropius, Henri Le Corbusier, and Mies van der Rohe, especially the International Style. In postmodern architecture, the modernist principle of abstraction, of geometric purity and simplicity, is displaced by multivocity and pluralism, by renewed interest in buildings as signs and signifiers, interest in their referential potential and resources. The modernist’s aspiration to buildings that are timeless in an important sense is itself read by postmodernists as an iconography that privileges the brave new world of science and technology, an aspiration that glorifies uncritically the industrial revolution of which it is itself a quintessential expression. This aspiration to timelessness is displaced in postmodern architecture by a direct and self-conscious openness to and engagement with history. It is this relative specificity of the concept postmodern architecture that enabled Charles Jencks to write that “Modern Architecture died in St. Louis Missouri on July 15, 1972 at 3:32 P.M.” Unfortunately, no remotely similar sentence can be written about postmodern philosophy. 

potency, for Aristotle, a kind of capacity that is a correlative of action. We require no instruction to grasp the difference between ‘X can do Y’ and ‘X is doing Y’, the latter meaning that the deed is actually being done. That an agent has a potency to do something is not a pure prediction so much as a generalization from past performance of individual or kind. Aristotle uses the example of a builder, meaning someone able to build, and then confronts the Megaric objection that the builder can be called a builder only when he actually builds. Clearly one who is doing something can do it, but Aristotle insists that the napping carpenter has the potency to hammer and saw. A potency based on an acquired skill like carpentry derives from the potency shared by those who acquire and those who do not acquire the skill. An unskilled worker can be said to be a builder “in potency,” not in the sense that he has the skill and can employ it, but in the sense that he can acquire the skill. In both acquisition and employment, ‘potency’ refers to the actual  either the actual acquisition of the skill or its actual use. These post-structuralism potency 726    726 potentiality, first practical attitude 727 correlatives emerged from Aristotle’s analysis of change and becoming. That which, from not having the skill, comes to have it is said to be “in potency” to that skill. From not having a certain shape, wood comes to have a certain shape. In the shaped wood, a potency is actualized. Potency must not be identified with the unshaped, with what Aristotle calls privation. Privation is the negation of P in a subject capable of P. Parmenides’ identification of privation and potency, according to Aristotle, led him to deny change. How can not-P become P? It is the subject of not-P to which the change is attributed and which survives the change that is in potency to X. 

poverty of the stimulus, a psychological phenomenon exhibited when behavior is stimulusunbound, and hence the immediate stimulus characterized in straightforward physical terms does not completely control behavior. Human beings sort stimuli in various ways and hosts of influences seem to affect when, why, and how we respond  our background beliefs, facility with language, hypotheses about stimuli, etc. Suppose a person visiting a museum notices a painting she has never before seen. Pondering the unfamiliar painting, she says, “an ambitious visual synthesis of the music of Mahler and the poetry of Keats.” If stimulus painting controls response, then her utterance is a product of earlier responses to similar stimuli. Given poverty of the stimulus, no such control is exerted by the stimulus the painting. Of course, some influence of response must be conceded to the painting, for without it there would be no utterance. However, the utterance may well outstrip the visitor’s conditioning and learning history. Perhaps she had never before talked of painting in terms of music and poetry. The linguist Noam Chomsky made poverty of the stimulus central to his criticism of B. F. Skinner’s Verbal Behavior 1957. Chomsky argued that there is no predicting, and certainly no critical stimulus control of, much human behavior. G.A.G. power, a disposition; an ability or capacity to yield some outcome. One tradition which includes Locke distinguishes active and passive powers. A knife has the active power to slice an apple, which has the passive power to be sliced by the knife. The distinction seems largely grammatical, however. Powers act in concert: the power of a grain of salt to dissolve in water and the water’s power to dissolve the salt are reciprocal and their manifestations mutual. Powers or dispositions are sometimes thought to be relational properties of objects, properties possessed only in virtue of objects standing in appropriate relations to other objects. However, if we distinguish, as we must, between a power and its manifestation, and if we allow that an object could possess a power that it never manifested a grain of salt remains soluble even if it never dissolves, it would seem that an object could possess a power even if appropriate reciprocal partners for its manifestation were altogether non-existent. This appears to have been Locke’s view An Essay concerning Human Understanding, 1690 of “secondary qualities” colors, sounds, and the like, which he regarded as powers of objects to produce certain sorts of sensory experience in observers. Philosophers who take powers seriously disagree over whether powers are intrinsic, “built into” properties this view, defended by C. B. Martin, seems to have been Locke’s, or whether the connection between properties and the powers they bestow is contingent, dependent perhaps upon contingent laws of nature a position endorsed by Armstrong. Is the solubility of salt a characteristic built into the salt, or is it a “second-order” property possessed by the salt in virtue of i the salt’s possession of some “firstorder” property and ii the laws of nature? Reductive analyses of powers, though influential, have not fared well. Suppose a grain of salt is soluble in water. Does this mean that if the salt were placed in water, it would dissolve? No. Imagine that were the salt placed in water, a technician would intervene, imposing an electromagnetic field, thereby preventing the salt from dissolving. Attempts to exclude “blocking” conditions  by appending “other things equal” clauses perhaps  face charges of circularity: in nailing down what other things must be equal we find ourselves appealing to powers. Powers evidently are fundamental features of our world. 

practical reason, the capacity for argument or demonstrative inference, considered in its application to the task of prescribing or selecting behavior. Some philosophical concerns in this area pertain to the actual thought processes by which plans of action are formulated and carried out in practical situations. A second major issue is what role, if any, practical reason plays in determining norms of conduct. Here there are two fundamental positions. Instrumentalism is typified by Hume’s claim that reason is, and ought only to be, the slave of the passions. According to instrumentalism, reason by itself is incapable of influencing action directly. It may do so indirectly, by disclosing facts that arouse motivational impulses. And it fulfills an indispensable function in discerning meansend relations by which our objectives may be attained. But none of those objectives is set by reason. All are set by the passions  the desiderative and aversive impulses aroused in us by what our cognitive faculties apprehend. It does not follow from this alone that ethical motivation reduces to mere desire and aversion, based on the pleasure and pain different courses of action might afford. There might yet be a specifically ethical passion, or it might be that independently based moral injunctions have in themselves a special capacity to provoke ordinary desire and aversion. Nevertheless, instrumentalism is often associated with the view that pleasure and pain, happiness and unhappiness, are the sole objects of value and disvalue, and hence the only possible motivators of conduct. Hence, it is claimed, moral injunctions must be grounded in these motives, and practical reason is of interest only as subordinated to inclination. The alternative to instrumentalism is the view championed by Kant, that practical reason is an autonomous source of normative principles, capable of motivating behavior independently of ordinary desire and aversion. On this view it is the passions that lack intrinsic moral import, and the function of practical reason is to limit their motivational role by formulating normative principles binding for all rational agents and founded in the operation of practical reason itself. Theories of this kind usually view moral principles as grounded in consistency, and an impartial respect for the autonomy of all rational agents. To be morally acceptable, principles of conduct must be universalizable, so that all rational agents could behave in the same way without their conduct either destroying itself or being inconsistently motivated. There are advantages and disadvantages to each of these views. Instrumentalism offers a simpler account of both the function of practical reason and the sources of human motivation. But it introduces a strong subjective element by giving primacy to desire, thereby posing a problem of how moral principles can be universally binding. The Kantian approach offers more promise here, since it makes universalizability essential to any type of behavior being moral. But it is more complex, and the claim that the deliverances of practical reason carry intrinsic motivational force is open to challenge. 

practical reasoning, the inferential process by which considerations for or against envisioned courses of action are brought to bear on the formation and execution of intention. The content of a piece of practical reasoning is a practical argument. Practical arguments can be complex, but they are often summarized in syllogistic form. Important issues concerning practical reasoning include how it relates to theoretical reasoning, whether it is a causal process, and how it can be evaluated. Theories of practical reasoning tend to divide into two basic categories. On one sort of view, the intrinsic features of practical reasoning exhibit little or no difference from those of theoretical reasoning. What makes practical reasoning practical is its subject matter and motivation. Hence the following could be a bona fide practical syllogism: Exercise would be good for me. Jogging is exercise. Therefore, jogging would be good for me. This argument has practical subject matter, and if made with a view toward intention formation it would be practical in motivation also. But it consists entirely of propositions, which are appropriate contents for belief-states. In principle, therefore, an agent could accept its conclusion without intending or even desiring to jog. Intention formation requires a further step. But if the content of an intention cannot be a proposition, that step could not count in itself as practical reasoning unless such reasoning can employ the contents of strictly practical mental states. Hence many philosophers call for practical syllogisms such as: Would that I exercise. Jogging is exercise. Therefore, I shall go jogging. Here the first premise is optative and understood to represent the content of a desire, and the conclusion is the content of a decision or act of intention formation. These contents are not true or false, and so are not propositions. Theories that restrict the contents of practical reasoning to propositions have the advantage that they allow such reasoning to be evaluated in terms of familiar logical principles. Those that permit the inclusion of optative content entail a need for more complex modes of evaluation. However, they bring more of the process of intention formation under the aegis of reason; also, they can be extended to cover the execution of intentions, in terms of syllogisms that terminate in volition. Both accounts must deal with cases of self-deception, in which the considerations an agent cites to justify a decision are not those from which it sprang, and cases of akrasia, where the agent views one course of action as superior, yet carries out another. Because mental content is always abstract, it cannot in itself be a nomic cause of behavior. But the states and events to which it belongs  desires, beliefs, etc.  can count as causes, and are so treated in deterministic explanations of action. Opponents of determinism reject this step, and seek to explain action solely through the teleological or justifying force carried by mental content. Practical syllogisms often summarize very complex thought processes, in which multiple options are considered, each with its own positive and negative aspects. Some philosophers hold that when successfully concluded, this process issues in a judgment of what action would be best all things considered  i.e., in light of all relevant considerations. Practical reasoning can be evaluated in numerous ways. Some concern the reasoning process itself: whether it is timely and duly considers the relevant alternatives, as well as whether it is well structured logically. Other concerns have to do with the products of practical reasoning. Decisions may be deemed irrational if they result in incompatible intentions, or conflict with the agent’s beliefs regarding what is possible. They may also be criticized if they conflict with the agent’s best interests. Finally, an agent’s intentions can fail to accord with standards of morality. The relationship among these ways of evaluating intentions is important to the foundations of ethics. 

practition, Castañeda’s term for the characteristic content of practical thinking. Each practition represents an action as something to be done, say, as intended, commanded, recommended, etc., and not as an accomplishment or prediction. Thus, unlike propositions, practitions are not truth-valued, but they can be components of valid arguments and so possess values akin to truth; e.g., the command ‘James, extinguish your cigar!’ seems legitimate given that James is smoking a cigar in a crowded bus. Acknowledging practitions is directly relevant to many other fields. 

praedicamenta singular: praedicamentum, in medieval philosophy, the ten Aristotelian categories: substance, quantity, quality, relation, where, when, position i.e., orientation  e.g., “upright”, having, action, and passivity. These were the ten most general of all genera. All of them except substance were regarded as accidental. It was disputed whether this tenfold classification was intended as a linguistic division among categorematic terms or as an ontological division among extralinguistic realities. Some authors held that the division was primarily linguistic, and that extralinguistic realities were divided according to some but not all the praedicamenta. Most authors held that everything in any way real belonged to one praedicamentum or another, although some made an exception for God. But authors who believed in complexe significabile usually regarded them as not belonging practical syllogism praedicamenta 729    729 to any praedicamentum. 

pragmatic contradiction, a contradiction that is generated by pragmatic rather than logical implication. A logically implies B if it is impossible for B to be false if A is true, whereas A pragmatically implies B if in most but not necessarily all contexts, saying ‘A’ can reasonably be taken as indicating that B is true. Thus, if I say, “It’s raining,” what I say does not logically imply that I believe that it is raining, since it is possible for it to be raining without my believing it is. Nor does my saying that it is raining logically imply that I believe that it is, since it is possible for me to say this without believing it. But my saying this does pragmatically imply that I believe that it is raining, since normally my saying this can reasonably be taken to indicate that I believe it. Accordingly, if I were to say, “It’s raining but I don’t believe that it’s raining,” the result would be a pragmatic contradiction. The first part “It’s raining” does not logically imply the negation of the second part “I don’t believe that it’s raining” but my saying the first part does pragmatically imply the negation of the second part. 

pragmatism, a philosophy that stresses the relation of theory to praxis and takes the continuity of experience and nature as revealed through the outcome of directed action as the starting point for reflection. Experience is the ongoing transaction of organism and environment, i.e., both subject and object are constituted in the process. When intelligently ordered, initial conditions are deliberately transformed according to ends-inview, i.e., intentionally, into a subsequent state of affairs thought to be more desirable. Knowledge is therefore guided by interests or values. Since the reality of objects cannot be known prior to experience, truth claims can be justified only as the fulfillment of conditions that are experimentally determined, i.e., the outcome of inquiry. As a philosophic movement, pragmatism was first formulated by Peirce in the early 1870s in the Metaphysical Club in Cambridge, Massachusetts; it was announced as a distinctive position in James’s 1898 address to the Philosophical Union at the  of California at Berkeley, and further elaborated according to the Chicago School, especially by Dewey, Mead, and Jane Addams 18601935. Emphasis on the reciprocity of theory and praxis, knowledge and action, facts and values, follows from its postDarwinian understanding of human experience, including cognition, as a developmental, historically contingent, process. C. I. Lewis’s pragmatic a priori and Quine’s rejection of the analytic synthetic distinction develop these insights further. Knowledge is instrumental  a tool for organizing experience satisfactorily. Concepts are habits of belief or rules of action. Truth cannot be determined solely by epistemological criteria because the adequacy of these criteria cannot be determined apart from the goals sought and values instantiated. Values, which arise in historically specific cultural situations, are intelligently appropriated only to the extent that they satisfactorily resolve problems and are judged worth retaining. According to pragmatic theories of truth, truths are beliefs that are confirmed in the course of experience and are therefore fallible, subject to further revision. True beliefs for Peirce represent real objects as successively confirmed until they converge on a final determination; for James, leadings that are worthwhile; and according to Dewey’s theory of inquiry, the transformation of an indeterminate situation into a determinate one that leads to warranted assertions. Pragmatic ethics is naturalistic, pluralistic, developmental, and experimental. It reflects on the motivations influencing ethical systems, examines the individual developmental process wherein an individual’s values are gradually distinguished from those of society, situates moral judgments within problematic situations irreducibly individual and social, and proposes as ultimate criteria for decision making the value for life as growth, determined by all those affected by the actual or projected outcomes. The original interdisciplinary development of pragmatism continues in its influence on the humanities. Oliver Wendell Holmes, Jr., member of the Metaphysical Club, later justice of the U.S. Supreme Court, developed a pragmatic theory of law. Peirce’s Principle of Pragmatism, by which meaning resides in conceivable practical effects, and his triadic theory of signs developed into the pragmatic ambiguity pragmatism 730    730 field of semiotics. James’s Principles of Psychology 1890 not only established experimental psychology in North America, but shifted philosophical attention away from abstract analyses of rationality to the continuity of the biological and the mental. The reflex arc theory was reconstructed into an interactive loop of perception, feeling, thinking, and behavior, and joined with the selective interest of consciousness to become the basis of radical empiricism. Mead’s theory of the emergence of self and mind in social acts and Dewey’s analyses of the individual and society influenced the human sciences. Dewey’s theory of education as community-oriented, based on the psychological developmental stages of growth, and directed toward full participation in a democratic society, was the philosophical basis of progressive education. 

praxis from Grecian prasso, ‘doing’, ‘acting’, in Aristotle, the sphere of thought and action that comprises the ethical and political life of man, contrasted with the theoretical designs of logic and epistemology theoria. It was thus that ‘praxis’ acquired its general definition of ‘practice’ through a contrastive comparison with ‘theory’. Throughout the history of Western philosophy the concept of praxis found a place in a variety of philosophical vocabularies. Marx and the neoMarxists linked the concept with a production paradigm in the interests of historical explanation. Within such a scheme of things the activities constituting the relations of production and exchange are seen as the dominant features of the socioeconomic history of humankind. Significations of ‘praxis’ are also discernible in the root meaning of pragma deed, affair, which informed the development of American pragmatism. In more recent times the notion of praxis has played a prominent role in the formation of the school of critical theory, in which the performatives of praxis are seen to be more directly associated with the entwined phenomena of discourse, communication, and social practices. The central philosophical issues addressed in the current literature on praxis have to do with the theorypractice relationship and the problems associated with a value-free science. The general thrust is that of undermining or subverting the traditional bifurcation of theory and practice via a recognition of praxis-oriented endeavors that antedate both theory construction and the construal of practice as a mere application of theory. Both the project of “pure theory,” which makes claims for a value-neutral standpoint, and the purely instrumentalist understanding of practice, as itself shorn of discernment and insight, are jettisoned. The consequent philosophical task becomes that of understanding human thought and action against the backdrop of the everyday communicative endeavors, habits, and skills, and social practices that make up our inheritance in the world. 

Praxis school, a school of philosophy originating in Zagreb and Belgrade which, from 1964 to 1974, published the international edition of the leading postwar Marxist journal Praxis. During the same period, it organized the Korcula Summer School, which attracted scholars from around the Western world. In a reduced form the school continues each spring with the Social Philosophy Course in Dubrovnik, Croatia. The founders of praxis philosophy include Gajo Petrovic Zagreb, Milan Kangrga Zagreb, and Mihailo Markovic Belgrade. Another wellknown member of the group is Svetozar Stojanovic Belgrade, and a second-generation leader is Gvozden Flego Zagreb. The Praxis school emphasized the writings of the young Marx while subjecting dogmatic Marxism to one of its strongest criticisms. Distinguishing between Marx’s and Engels’s writings and emphasizing alienation and a dynamic concept of the human being, it contributed to a greater understanding of the interrelationship between the individual and society. Through its insistence on Marx’s call for a “ruthless critique,” the school stressed open inquiry and freedom of speech in both East and West. Quite possibly the most important and original philosopher of the group, and certainly Croatia’s leading twentieth-century philosopher, was Gajo Petrovic 192793. He called for 1 understanding philosophy as a radical critique of all existing things, and 2 understanding human beings as beings of praxis and creativity. This later led to a view of human beings as revolutionary by nature. At present he is probably best remembered for his Marx in the Mid-Twentieth Century and Philosophie und Revolution. Milan Kangrga b.1923 also emphasizes human creativity while insisting that one should understand human beings as producers who humanize nature. An ethical problematic of humanity can pragmatism, ethical Praxis school 731    731 be realized through a variety of disciplines that include aesthetics, philosophical anthropolgy, theory of knowledge, ontology, and social thought. Mihailo Markovic b.1923, a member of the Belgrade Eight, is best known for his theory of meaning, which leads him to a theory of socialist humanism. His most widely read work in the West is From Affluence to Praxis: Philosophy and Social Criticism. 

preanalytic, considered but naive; commonsensical; not tainted by prior explicit theorizing; said of judgments and, derivatively, of beliefs or intuitions underlying such judgments. Preanalytic judgments are often used to test philosophical theses. All things considered, we prefer theories that accord with preanalytic judgments to those that do not, although most theorists exhibit a willingness to revise preanalytic assessments in light of subsequent inquiry. Thus, a preanalytic judgment might be thought to constitute a starting point for the philosophical consideration of a given topic. Is justice giving every man his due? It may seem so, preanalytically. Attention to concrete examples, however, may lead us to a different view. It is doubtful, even in such cases, that we altogether abandon preanalytic judgments. Rather, we endeavor to reconcile apparently competing judgments, making adjustments in a way that optimizes overall coherence. 

predicables, also praedicabilia, sometimes called the quinque voces five words, in medieval philosophy, genus, species, difference, proprium, and accident, the five main ways general predicates can be predicated. The list comes from Porphyry’s Isagoge. It was debated whether it applies to linguistic predicates only or also to extralinguistic universals. Things that have accidents can exist without them; other predicables belong necessarily to whatever has them. The Aristotelian/Porphyrian notion of “inseparable accident” blurs this picture. Genus and species are natural kinds; other predicables are not. A natural kind that is not a narrowest natural kind is a genus; one that is not a broadest natural kind is a species. Some genera are also species. A proprium is not a species, but is coextensive with one. A difference belongs necessarily to whatever has it, but is neither a natural kind nor coextensive with one. 

preexistence, existence of the individual soul or psyche prior to its current embodiment, when the soul or psyche is taken to be separable and capable of existing independently from its embodiment. The current embodiment is then often described as a reincarnation of the soul. Plato’s Socrates refers to such a doctrine several times in the dialogues, notably in the myth of Er in Book X of the Republic. The doctrine is distinguished from two other teachings about the soul: creationism, which holds that the individual human soul is directly created by God, and traducianism, which held that just as body begets body in biological generation, so the soul of the new human being is begotten by the parental soul. In Hinduism, the cycle of reincarnations represents the period of estrangement and trial for the soul or Atman before it achieves release moksha.

prescriptivism, the theory that evaluative judgments necessarily have prescriptive meaning. Associated with noncognitivism and moral antirealism, prescriptivism holds that moral language is such that, if you say that you think one ought to do a certain kind of act, and yet you are not committed to doing that kind of act in the relevant circumstances, then you either spoke insincerely or are using the word ‘ought’ in a less than full-blooded sense. Prescriptivism owes its stature to Hare. One of his innovations is the distinction between “secondarily evaluative” and “primarily evaluative” words. The prescriptive meaning of secondarily evaluative words, such as ‘soft-hearted’ or ‘chaste’, may vary significantly while their descriptive meanings stay relatively constant. Hare argues the reverse for the primarily evaluative words ‘good’, ‘bad’, ‘right’, ‘wrong’, ‘ought’, and ‘must’. For example, some people assign to ‘wrong’ the descriptive meaning ‘forbidden by God’, others assign it the descriptive meaning ‘causes social conflict’, and others give it different descriptive meanings; but since all use ‘wrong’ with the same prescriptive meaning, they are using the same concept. In part to show how moral judgments can be prescriptive and yet have the same logical relations as indicative sentences, Hare distinguished between phrastics and neustics. The phrastic, or content, can be the same in indicative and prescriptive sentences; e.g., ‘Sam’s leaving’ is the phrastic not only of the indicative ‘Sam will leave’ but also of the prescription ‘Sam ought to leave’. Hare’s Language of Morals 1952 specified that the neustic indicates mood, i.e., whether the sentence is indicative, imperative, interrogative, etc. However, in an article in Mind 1989 and in Sorting Out Ethics 1997, he used ‘neustic’ to refer to the sign of subscription, and ‘tropic’ to refer to the sign of mood. Prescriptivity is especially important if moral judgments are universalizable. For then we can employ golden rulestyle moral reasoning. 

pre-Socratics: cf. pre-Griceians. the early Grecian philosophers who were not influenced by Socrates. Generally they lived before Socrates, but some are contemporary with him or even younger. The classification though not the term goes back to Aristotle, who saw Socrates’ humanism and emphasis on ethical issues as a watershed in the history of philosophy. Aristotle rightly noted that philosophers prior to Socrates had stressed natural philosophy and cosmology rather than ethics. He credited them with discovering material principles and moving causes of natural events, but he criticized them for failing to stress structural elements of things formal causes and values or purposes final causes. Unfortunately, no writing of any pre-Socratic survives in more than a fragmentary form, and evidence of their views is thus often indirect, based on reports or criticisms of later writers. In order to reconstruct pre-Socratic thought, scholars have sought to collect testimonies of ancient sources and to identify quotations from the preSocratics in those sources. As modern research has revealed flaws in the interpretations of ancient witnesses, it has become a principle of exegesis to base reconstructions of their views on the actual words of the pre-Socratics themselves wherever possible. Because of the fragmentary and derivative nature of our evidence, even basic principles of a philosopher’s system sometimes remain controversial; nevertheless, we can say that thanks to modern methods of historiography, there are many points we understand better than ancient witnesses who are our secondary sources. Our best ancient secondary source is Aristotle, who lived soon after the pre-Socratics and had access to most of their writings. He interprets his predecessors from the standpoint of his own theory; but any historian must interpret philosophers in light of some theoretical background. Since we have extensive writings of Aristotle, we    733 pre-Socratics pre-Socratics 734 understand his system and can filter out his own prejudices. His colleague Theophrastus was the first professional historian of philosophy. Adopting Aristotle’s general framework, he systematically discussed pre-Socratic theories. Unfortunately his work itself is lost, but many fragments and summaries of parts of it remain. Indeed, virtually all ancient witnesses writing after Theophrastus depend on him for their general understanding of the early philosophers, sometimes by way of digests of his work. When biography became an important genre in later antiquity, biographers collected facts, anecdotes, slanders, chronologies often based on crude a priori assumptions, lists of book titles, and successions of school directors, which provide potentially valuable information. By reconstructing ancient theories, we can trace the broad outlines of pre-Socratic development with some confidence. The first philosophers were the Milesians, philosophers of Miletus on the Ionian coast of Asia Minor, who in the sixth century B.C. broke away from mythological modes of explanation by accounting for all phenomena, even apparent prodigies of nature, by means of simple physical hypotheses. Aristotle saw the Milesians as material monists, positing a physical substrate  of water, or the apeiron, or air; but their material source was probably not a continuing substance that underlies all changes as Aristotle thought, but rather an original stuff that was transformed into different stuffs. Pythagoras migrated from Ionia to southern Italy, founding a school of Pythagoreans who believed that souls transmigrated and that number was the basis of all reality. Because Pythagoras and his early followers did not publish anything, it is difficult to trace their development and influence in detail. Back in Ionia, Heraclitus criticized Milesian principles because he saw that if substances changed into one another, the process of transformation was more important than the substances that appeared in the cycle of changes. He thus chose the unstable substance fire as his material principle and stressed the unity of opposites. Parmenides and the Eleatic School criticized the notion of notbeing that theories of physical transformations seemed to presuppose. One cannot even conceive of or talk of not-being; hence any conception that presupposes not-being must be ruled out. But the basic notions of coming-to-be, differentiation, and indeed change in general presuppose not-being, and thus must be rejected. Eleatic analysis leads to the further conclusion, implicit in Parmenides, explicit in Melissus, that there is only one substance, what-is. Since this substance does not come into being or change in any way, nor does it have any internal differentiations, the world is just a single changeless, homogeneous individual. Parmenides’ argument seems to undermine the foundations of natural philosophy. After Parmenides philosophers who wished to continue natural philosophy felt compelled to grant that coming-to-be and internal differentiation of a given substance were impossible. But in order to accommodate natural processes, they posited a plurality of unchanging, homogeneous elements  the four elements of Empedocles, the elemental stuffs of Anaxagoras, the atoms of Democritus  that by arrangement and rearrangement could produce the cosmos and the things in it. There is no real coming-to-be and perishing in the world since the ultimate substances are everlasting; but some limited kind of change such as chemical combination or mixture or locomotion could account for changing phenomena in the world of experience. Thus the “pluralists” incorporated Eleatic principles into their systems while rejecting the more radical implications of the Eleatic critique. Pre-Socratic philosophers developed more complex systems as a response to theoretical criticisms. They focused on cosmology and natural philosophy in general, championing reason and nature against mythological traditions. Yet the pre-Socratics have been criticized both for being too narrowly scientific in interest and for not being scientific experimental enough. While there is some justice in both criticisms, their interests showed breadth as well as narrowness, and they at least made significant conceptual progress in providing a framework for scientific and philosophical ideas. While they never developed sophisticated theories of ethics, logic, epistemology, or metaphysics, nor invented experimental methods of confirmation, they did introduce the concepts that ultimately became fundamental in modern theories of cosmic, biological, and cultural evolution, as well as in atomism, genetics, and social contract theory. Because the Socratic revolution turned philosophy in different directions, the pre-Socratic line died out. But the first philosophers supplied much inspiration for the sophisticated fourthcentury systems of Plato and Aristotle as well as the basic principles of the great Hellenistic schools, Epicureanism, Stoicism, and Skepticism. 

presupposition, 1 a relation between sentences or statements, related to but distinct from entailment and assertion; 2 what a speaker takes to be understood in making an assertion. The first notion is semantic, the second pragmatic. The semantic notion was introduced by Strawson in his attack on Russell’s theory of descriptions, and perhaps anticipated by Frege. Strawson argued that ‘The present king of France is bald’ does not entail ‘There is a present king of France’ as Russell held, but instead presupposes it. Semantic presupposition can be defined thus: a sentence or statement S presupposes a sentence or statement SH provided S entails SH and the negation of S also entails SH . SH is a condition of the truth or falsity of S. Thus, since ‘There is a present king of France’ is false, ‘The present king of France is bald’ is argued to be neither true nor false. So construed, presupposition is defined in terms of, but is distinct from, entailment. It is also distinct from assertion, since it is viewed as a precondition of the truth or falsity of what is asserted. The pragmatic conception does not appeal to truth conditions, but instead contrasts what a speaker presupposes and what that speaker asserts in making an utterance. Thus, someone who utters ‘The present king of France is bald’ presupposes  believes and believes that the audience believes  that there is a present king of France, and asserts that this king is bald. So conceived, presuppositions are beliefs that the speaker takes for granted; if these beliefs are false, the utterance will be inappropriate in some way, but it does not follow that the sentence uttered lacks a truth-value. These two notions of presupposition are logically independent. On the semantic characterization, presupposition is a relation between sentences or statements requiring that there be truth-value gaps. On the pragmatic characterization, it is speakers rather than sentences or statements that have presuppositions; no truth-value gaps are required. Many philosophers and linguists have argued for treating what have been taken to be cases of semantic presupposition, including the one discussed above, as pragmatic phenomena. Some have denied that semantic presuppositions exist. If not, intuitions about presupposition do not support the claims that natural languages have truth-value gaps and that we need a three-valued logic to represent the semantics of natural language adequately. Presupposition is also distinct from implicature. If someone reports that he has just torn his coat and you say, “There’s a tailor shop around the corner,” you conversationally implicate that the shop is open. This is not a semantic presupposition because if it is false that the shop is open, there is no inclination to say that your assertion was neither true nor false. It is not a pragmatic presupposition because it is not something you believe the hearer believes.

pretheoretical, independent of theory. More specifically, a proposition is pretheoretical, according to some philosophers, if and only if it does not depend for its plausibility or implausibility on theoretical considerations or considerations of theoretical analysis. The term ‘preanalytic’ is often used synonymously with ‘pretheoretical’, but the former is more properly paired with analysis rather than with theory. Some philosophers characterize pretheoretical propositions as “intuitively” plausible or implausible. Such propositions, they hold, can regulate philosophical theorizing as follows: in general, an adequate philosophical theory should not conflict with intuitively plausible propositions by implying intuitively implausible propositions, and should imply intuitively plausible propositions. Some philosophers grant that theoretical considerations can override “intuitions”  in the sense of intuitively plausible propositions  when overall theoretical coherence or reflective equilibrium is thereby enhanced. 

Price, Richard 172391, Welsh Dissenting minister, actuary, and moral philosopher. His main work, A Review of the Principal Question in Morals 1758, is a defense of rationalism in ethics. He argued that the understanding immediately perceives simple, objective, moral qualities of actions. The resulting intuitive knowledge of moral truths is accompanied by feelings of approval and disapproval responsible for moral motivation. He also wrote influential papers on life expectancy, public finance, and annuities; communicated to the Royal Society the paper by his deceased friend Thomas Bayes containing Bayes’s theorem; and defended the American and French revolutions. Burke’s Reflections on the Revolution in France is a response to one of Price’s sermons. J.W.A. presupposition Price, Richard 735    735 Prichard, Harold Arthur 18711947, English philosopher and founder of the Oxford school of intuitionism. An Oxford fellow and professor, he published Kant’s Theory of Knowledge 1909 and numerous essays, collected in Moral Obligation 1949, 1968 and in Knowledge and Perception 1950. Prichard was a realist in his theory of knowledge, following Cook Wilson. He held that through direct perception in concrete cases we obtain knowledge of universals and of necessary connections between them, and he elaborated a theory about our knowledge of material objects. In “Does Moral Philosophy Rest on a Mistake?” 1912 he argued powerfully that it is wrong to think that a general theory of obligation is possible. No single principle captures the various reasons why obligatory acts are obligatory. Only by direct perception in particular cases can we see what we ought to do. With this essay Prichard founded the Oxford school of intuitionism, carried on by, among others, Ross.

Priestley, Joseph 17331804, British experimental chemist, theologian, and philosopher. In 1774 he prepared oxygen by heating mercuric oxide. Although he continued to favor the phlogiston hypothesis, his work did much to discredit that idea. He discovered many gases, including ammonia, sulfur dioxide, carbon monoxide, and hydrochloric acid. While studying the layer of carbon dioxide over a brewing vat, he conceived the idea of dissolving it under pressure. The resulting “soda water” was famous throughout Europe. His Essay on Government 1768 influenced Jefferson’s ideas in the American Declaration of Independence. The essay also contributed to the utilitarianism of Bentham, supplying the phrase “the greatest happiness of the greatest number.” Priestley modified the associationism of Locke, Hume, and Hartley, holding that a sharp distinction must be drawn between the results of association in forming natural propensities and its effects on the development of moral ideas. On the basis of this distinction, he argued, against Hume, that differences in individual moral sentiments are results of education, through the association of ideas, a view anticipated by Helvétius. Priestley served as minister to anti-Establishment congregations. His unpopular stress on individual freedom resulted in his move to Pennsylvania, where he spent his last years.

prime mover, the original source and cause of motion change in the universe  an idea that was developed by Aristotle and became important in Judaic, Christian, and Islamic thought about God. According to Aristotle, something that is in motion a process of change is moving from a state of potentiality to a state of actuality. For example, water that is being heated is potentially hot and in the process of becoming actually hot. If a cause of change must itself actually be in the state that it is bringing about, then nothing can produce motion in itself; whatever is in motion is being moved by another. For otherwise something would be both potentially and actually in the same state. Thus, the water that is potentially hot can become hot only by being changed by something else the fire that is actually hot. The prime mover, the original cause of motion, must itself, therefore, not be in motion; it is an unmoved mover. Aquinas and other theologians viewed God as the prime mover, the ultimate cause of all motion. Indeed, for these theologians the argument to establish the existence of a first mover, itself unmoved, was a principal argument used in their efforts to prove the existence of God on the basis of reason. Many modern thinkers question the argument for a first mover on the ground that it does not seem to be logically impossible that the motion of one thing be caused by a second thing whose motion in turn is caused by a third thing, and so on without end. Defenders of the argument claim that it presupposes a distinction between two different causal series, one temporal and one simultaneous, and argue that the objection succeeds only against a temporal causal series. Prichard, Harold Arthur prime mover 736    736 

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principium individuationis, the cause or basis of individuality in individuals; what makes something individual as opposed to universal, e.g., what makes the cat Minina individual and thus different from the universal, cat. Questions regarding the principle of individuation were first raised explicitly in the early Middle Ages. Classical authors largely ignored individuation; their ontological focus was on the problem of universals. The key texts that originated the discussion of the principle of individuation are found in Boethius. Between Boethius and 1150, individuation was always discussed in the context of more pressing issues, particularly the problem of universals. After 1150, individuation slowly emerged as a focus of attention, so that by the end of the thirteenth century it had become an independent subject of discussion, especially in Aquinas and Duns Scotus. Most early modern philosophers conceived the problem of individuation epistemically rather than metaphysically; they focused on the discernibility of individuals rather than the cause of individuation Descartes. With few exceptions Karl Popper, the twentieth century has followed this epistemic approach P. F. Strawson. 

principle of bivalence, the principle that any significant statement is either true or false. It is often confused with the principle of excluded middle. Letting ‘Tp’ stand for ‘p is true’ and ‘Tp’ for ‘p is false’ and otherwise using standard logical notation, bivalence is ‘Tp 7 T-p’ and excluded middle is ‘T p 7 -p’. That they are different principles is shown by the fact that in probability theory, where ‘Tp’ can be expressed as ‘Prp % 1’, bivalence ‘Pr p % 1 7 Pr ~p % 1’ is not true for all values of p  e.g. it is not true where ‘p’ stands for ‘given a fair toss of a fair die, the result will be a six’ a statement with a probability of 1 /6, where -p has a probability of 5 /6  but excluded middle ‘Prp 7 -p % 1’ is true for all definite values of p, including the probability case just given. If we allow that some significant statements have no truth-value or probability and distinguish external negation ‘Tp’ from internal negation ‘T-p’, we can distinguish bivalence and excluded middle from the principle of non-contradiction, namely, ‘-Tp • T-p’, which is equivalent to ‘-Tp 7 -T-p’. Standard truth-functional logic sees no difference between ‘p’ and ‘Tp’, or ‘-Tp’ and ‘T-p’, and thus is unable to distinguish the three principles. Some philosophers of logic deny there is such a difference.

principle of contradiction, also called principle of non-contradiction, the principle that a statement and its negation cannot both be true. It can be distinguished from the principle of bivalence, and given certain controversial assumptions, from the principle of excluded middle; but in truth-functional logic all three are regarded as equivalent. Outside of formal logic the principle of non-contradiction is best expressed as Aristotle expresses it: “Nothing can both be and not be at the same time in the same respect.” 

principle of double effect, the view that there is a morally relevant difference between those consequences of our actions we intend and those we do not intend but do still foresee. According to the principle, if increased literacy means a higher suicide rate, those who work for education are not guilty of driving people to kill themselves. A physician may give a patient painkillers foreseeing that they will shorten his life, even though the use of outright poisons is forbidden and the physician does not intend to shorten the patient’s life. An army attacking a legitimate military target may accept as inevitable, without intending to bring about, the deaths of a number of civilians. Traditional moral theologians affirmed the existence of exceptionless prohibitions such as primitive symbol principle of double effect 737    737 that against taking an innocent human life, while using the principle of double effect to resolve hard cases and avoid moral blind alleys. They held that one may produce a forbidden effect, provided 1 one’s action also had a good effect, 2 one did not seek the bad effect as an end or as a means, 3 one did not produce the good effect through the bad effect, and 4 the good effect was important enough to outweigh the bad one. Some contemporary philosophers and Roman Catholic theologians hold that a modified version of the principle of double effect is the sole justification of deadly deeds, even when the person killed is not innocent. They drop any restriction on the causal sequence, so that e.g. it is legitimate to cut off the head of an unborn child to save the mother’s life. But they oppose capital punishment on the ground that those who inflict it require the death of the convict as part of their plan. They also play down the fourth requirement, on the ground that the weighing of incommensurable goods it requires is impossible. Consequentialists deny the principle of double effect, as do those for whom the crucial distinction is between what we cause by our actions and what just happens. In the most plausible view, the principle does not presuppose exceptionless moral prohibitions, only something stronger than prima facie duties. It is easier to justify an oblique evasion of a moral requirement than a direct violation, even if direct violations are sometimes permissible. So understood, the principle is a guide to prudence rather than a substitute for it. 

principle of excluded middle, the principle that the disjunction of any significant statement with its negation is always true; e.g., ‘Either there is a tree over 500 feet tall or it is not the case that there is such a tree’. The principle is often confused with the principle of bivalence.

principle of indifference, a rule for assigning a probability to an event based on “parity of reasons.” According to the principle, when the “weight of reasons” favoring one event is equal to the “weight of reasons” favoring another, the two events should be assigned the same probability. When there are n mutually exclusive and collectively exhaustive events, and there is no reason to favor one over another, then we should be “indifferent” and the n events should each be assigned probability 1/n the events are equiprobable, according to the principle. This principle is usually associated with the names Bernoulli Ars Conjectandi, 1713 and Laplace Théorie analytique des probabilités, 1812, and was so called by J. M. Keynes A Treatise on Probability, 1921. The principle gives probability both a subjective “degree of belief” and a logical “partial logical entailment” interpretation. One rationale for the principle says that in ignorance, when no reasons favor one event over another, we should assign equal probabilities. It has been countered that any assignment of probabilities at all is a claim to some knowledge. Also, several seemingly natural applications of the principle, involving non-linearly related variables, have led to some mathematical contradictions, known as Bertrand’s paradox, and pointed out by Keynes. 

principle of insufficient reason, the principle that if there is no sufficient reason or explanation for something’s being the case, then it will not be the case. Since the rise of modern probability theory, many have identified the principle of insufficient reason with the principle of indifference a rule for assigning a probability to an event based on “parity of reasons”. The two principles are closely related, but it is illuminating historically and logically to view the principle of insufficient reason as the general principle stated above which is related to the principle of sufficient reason and to view the principle of indifference as a special case of the principle of insufficient reason applying to probabilities. As Mach noted, the principle of insufficient reason, thus conceived, was used by Archimedes to argue that a lever with equal weights at equal distances from a central fulcrum would not move, since if there is no sufficient reason why it should move one way or the other, it would not move one way or the other. Philosophers from Anaximander to Leibniz used the same principle to argue for various metaphysical theses. The principle of indifference can be seen to be a special case of this principle of insufficient reason applying to probabilities, if one reads the principle of indifference as follows: when there are N mutually exclusive and exhaustive events and there is no sufficient reason to believe that any one of them is more probable than any other, principle of excluded middle principle of insufficient reason 738    738 then no one of them is more probable than any other they are equiprobable. The idea of “parity of reasons” associated with the principle of indifference is, in such manner, related to the idea that there is no sufficient reason for favoring one outcome over another. This is significant because the principle of insufficient reason is logically equivalent to the more familiar principle of sufficient reason if something is [the case], then there is a sufficient reason for its being [the case]  which means that the principle of indifference is a logical consequence of the principle of sufficient reason. If this is so, we can understand why so many were inclined to believe the principle of indifference was an a priori truth about probabilities, since it was an application to probabilities of that most fundamental of all alleged a priori principles of reasoning, the principle of sufficient reason. Nor should it surprise us that the alleged a priori truth of the principle of indifference was as controversial in probability theory as was the alleged a priori truth of the principle of sufficient reason in philosophy generally. 

principle of plenitude, the principle that every genuine possibility is realized or actualized. This principle of the “fullness of being” was named by A. O. Lovejoy, who showed that it was commonly assumed throughout the history of Western science and philosophy, from Plato to Plotinus who associated it with inexhaustible divine productivity, through Augustine and other medieval philosophers, to the modern rationalists Spinoza and Leibniz and the Enlightenment. Lovejoy connected plenitude to the great chain of being, the idea that the universe is a hierarchy of beings in which every possible form is actualized. In the eighteenth century, the principle was “temporalized”: every possible form of creature would be realized  not necessarily at all times  but at some stage “in the fullness of time.” A clue about the significance of plenitude lies in its connection to the principle of sufficient reason everything has a sufficient reason [cause or explanation] for being or not being. Plenitude says that if there is no sufficient reason for something’s not being i.e., if it is genuinely possible, then it exists  which is logically equivalent to the negative version of sufficient reason: if something does not exist, then there is a sufficient reason for its not being.

principle of verifiability, a claim about what meaningfulness is: at its simplest, a sentence is meaningful provided there is a method for verifying it. Therefore, if a sentence has no such method, i.e., if it does not have associated with it a way of telling whether it is conclusively true or conclusively false, then it is meaningless. The purpose for which this verificationist principle was originally introduced was to demarcate sentences that are “apt to make a significant statement of fact” from “nonsensical” or “pseudo-” sentences. It is part of the emotive theory of content, e.g., that moral discourse is not literally, cognitively meaningful, and therefore, not facprinciple of limited variety principle of verifiability 739    739 tual. And, with the verifiability principle, the central European logical positivists of the 1920s hoped to strip “metaphysical discourse” of its pretensions of factuality. For them, whether there is a reality external to the mind, as the realists claim, or whether all reality is made up of “ideas” or “appearances,” as idealists claim, is a “meaningless pseudo-problem.” The verifiability principle proved impossible to frame in a form that did not admit all metaphysical sentences as meaningful. Further, it casts doubt on its own status. How was it to be verified? So, e.g., in the first edition of Language, Truth and Logic, Ayer proposed that a sentence is verifiable, and consequently meaningful, if some observation sentence can be deduced from it in conjunction with certain other premises, without being deducible from those other premises alone. It follows that any metaphysical sentence M is meaningful since ‘if M, then O’ always is an appropriate premise, where O is an observation sentence. In the preface to the second edition, Ayer offered a more sophisticated account: M is directly verifiable provided it is an observation sentence or it entails, in conjunction with certain observation sentences, some observation sentence that does not follow from them alone. And M is indirectly verifiable provided it entails, in conjunction with certain other premises, some directly verifiable sentence that does not follow from those other premises alone and these additional premises are either analytic or directly verifiable or are independently indirectly verifiable. The new verifiability principle is then that all and only sentences directly or indirectly verifiable are “literally meaningful.” Unfortunately, Ayer’s emendation admits every nonanalytic sentence. Let M be any metaphysical sentence and O1 and O2 any pair of observation sentences logically independent of each other. Consider sentence A: ‘either O1 or not-M and not-O2’. Conjoined with O2, A entails O1. But O2 alone does not entail O1. So A is directly verifiable. Therefore, since M conjoined with A entails O1, which is not entailed by A alone, M is indirectly verifiable. Various repairs have been attempted; none has succeeded. 

prisoner’s dilemma, a problem in game theory, and more broadly the theory of rational choice, that takes its name from a familiar sort of pleabargaining situation: Two prisoners Robin and Carol are interrogated separately and offered the same deal: If one of them confesses “defects” and the other does not, the defector will be given immunity from prosecution and the other will get a stiff prison sentence. If both confess, both will get moderate prison terms. If both remain silent cooperate with each other, both will get light prison terms for a lesser offense. There are thus four possible outcomes: 1 Robin confesses and gets immunity, while Carol is silent and gets a stiff sentence. 2 Both are silent and get light sentences. 3 Both confess and get moderate sentences. 4 Robin is silent and gets a stiff sentence, while Carol confesses and gets immunity. Assume that for Robin, 1 would be the best outcome, followed by 2, 3, and 4, in that order. Assume that for Carol, the best outcome is 4, followed by 2, 3, and 1. Each prisoner then reasons as follows: “My confederate will either confess or remain silent. If she confesses, I must do likewise, in order to avoid the ‘sucker’s payoff’ immunity for her, a stiff sentence for me. If she remains silent, then I must confess in order to get immunity  the best outcome for me. Thus, no matter what my confederate does, I must confess.” Under those conditions, both will confess, effectively preventing each other from achieving anything better than the option they both rank as only third-best, even though they agree that option 2 is second-best. This illustrative story attributed to A. W. Tucker must not be allowed to obscure the fact that many sorts of social interactions have the same structure. In general, whenever any two parties must make simultaneous or independent choices over a range of options that has the ordinal payoff structure described in the plea bargaining story, they are in a prisoner’s dilemma. Diplomats, negotiators, buyers, and sellers regularly find themselves in such situations. They are called iterated prisoner’s dilemmas if the same parties repeatedly face the same choices with each other. Moreover, there are analogous problems of cooperation and conflict at the level of manyperson interactions: so-called n-person prisoner’s diemmas or free rider problems. The provision of public goods provides an example. Suppose there is a public good, such as clean air, priority, conceptual prisoner’s dilemma 740    740 privacy, epistemic privation 741 national defense, or public radio, which we all want. Suppose that is can be provided only by collective action, at some cost to each of the contributors, but that we do not have to have a contribution from everyone in order to get it. Assume that we all prefer having the good to not having it, and that the best outcome for each of us would be to have it without cost to ourselves. So each of us reasons as follows: “Other people will either contribute enough to produce the good by themselves, or they will not. If they do, then I can have it cost-free the best option for me and thus I should not contribute. But if others do not contribute enough to produce the good by themselves, and if the probability is very low that my costly contribution would make the difference between success and failure, once again I should not contribute.” Obviously, if we all reason in this way, we will not get the public good we want. Such problems of collective action have been noticed by philosophers since Plato. Their current nomenclature, rigorous game-theoretic formulation, empirical study, and systematic philosophical development, however, has occurred since 1950. 

private language argument, an argument designed to show that there cannot be a language that only one person can speak  a language that is essentially private, that no one else can in principle understand. In addition to its intrinsic interest, the private language argument is relevant to discussions of linguistic rules and linguistic meaning, behaviorism, solipsism, and phenomenalism. The argument is closely associated with Wittgenstein’s Philosophical Investigations 1958. The exact structure of the argument is controversial; this account should be regarded as a standard one, but not beyond dispute. The argument begins with the supposition that a person assigns signs to sensations, where these are taken to be private to the person who has them, and attempts to show that this supposition cannot be sustained because no standards for the correct or incorrect application of the same sign to a recurrence of the same sensation are possible. Thus Wittgenstein supposes that he undertakes to keep a diary about the recurrence of a certain sensation; he associates it with the sign ‘S’, and marks ‘S’ on a calendar every day he has that sensation. Wittgenstein finds the nature of the association of the sign and sensation obscure, on the ground that ‘S’ cannot be given an ordinary definition this would make its meaning publicly accessible or even an ostensive definition. He further argues that there is no difference between correct and incorrect entries of ‘S’ on subsequent days. The initial sensation with which the sign ‘S’ was associated is no longer present, and so it cannot be compared with a subsequent sensation taken to be of the same kind. He could at best claim to remember the nature of the initial sensation, and judge that it is of the same kind as today’s. But since the memory cannot confirm its own accuracy, there is no possible test of whether he remembers the initial association of sign and sensation right today. Consequently there is no criterion for the correct reapplication of the sign ‘S’. Thus we cannot make sense of the notion of correctly reapplying ‘S’, and cannot make sense of the notion of a private language. The argument described appears to question only the claim that one could have terms for private mental occurrences, and may not seem to impugn a broader notion of a private language whose expressions are not restricted to signs for sensations. Advocates of Wittgenstein’s argument would generalize it and claim that the focus on sensations simply highlights the absence of a distinction between correct and incorrect reapplications of words. A language with terms for publicly accessible objects would, if private to its user, still be claimed to lack criteria for the correct reapplication of such terms. This broader notion of a private language would thus be argued to be equally incoherent. 

privation: H. P. Grice, “Negation and privation,” a lack of something that it is natural or good to possess. The term is closely associated with the idea that evil is itself only a lack of good, privatio boni. In traditional theistic religions everything other than God is created by God out of nothing, creation ex nihilo. Since, being perfect, God would create only what is good, the entire original creation and every creature from the most complex to the simplest are created entirely good. The original creation contains no evil whatever. What then is evil and how does it enter the world? The idea that evil is a privation of good does not mean, e.g., that a rock has some degree of evil because it lacks such good qualities as consciousness and courage. A thing has some degree of evil only if it lacks some good that is    741 privileged access privileged access 742 proper for that thing to possess. In the original creation each created thing possessed the goods proper to the sort of thing it was. According to Augustine, evil enters the world when creatures with free will abandon the good above themselves for some lower, inferior good. Human beings, e.g., become evil to the extent that they freely turn from the highest good God to their own private goods, becoming proud, selfish, and wicked, thus deserving the further evils of pain and punishment. One of the problems for this explanation of the origin of evil is to account for why an entirely good creature would use its freedom to turn from the highest good to a lesser good. 

privileged access: H. P. Grice, “Privileged access and incorrigibility,” special first-person awareness of the contents of one’s own mind. Since Descartes, many philosophers have held that persons are aware of the occurrent states of their own minds in a way distinct from both their mode of awareness of physical objects and their mode of awareness of the mental states of others. Cartesians view such apprehension as privileged in several ways. First, it is held to be immediate, both causally and epistemically. While knowledge of physical objects and their properties is acquired via spatially intermediate causes, knowledge of one’s own mental states involves no such causal chains. And while beliefs about physical properties are justified by appeal to ways objects appear in sense experience, beliefs about the properties of one’s own mental states are not justified by appeal to properties of a different sort. I justify my belief that the paper on which I write is white by pointing out that it appears white in apparently normal light. By contrast, my belief that white appears in my visual experience seems to be self-justifying. Second, Cartesians hold that first-person apprehension of occurrent mental contents is epistemically privileged in being absolutely certain. Absolute certainty includes infallibility, incorrigibility, and indubitability. That a judgment is infallible means that it cannot be mistaken; its being believed entails its being true even though judgments regarding occurrent mental contents are not necessary truths. That it is incorrigible means that it cannot be overridden or corrected by others or by the subject himself at a later time. That it is indubitable means that a subject can never have grounds for doubting it. Philosophers sometimes claim also that a subject is omniscient with regard to her own occurrent mental states: if a property appears within her experience, then she knows this. Subjects’ privileged access to the immediate contents of their own minds can be held to be necessary or contingent. Regarding corrigibility, for example, proponents of the stronger view hold that first-person reports of occurrent mental states could never be overridden by conflicting evidence, such as conflicting readings of brain states presumed to be correlated with the mental states in question. They point out that knowledge of such correlations would itself depend on first-person reports of mental states. If a reading of my brain indicates that I am in pain, and I sincerely claim not to be, then the law linking brain states of that type with pains must be mistaken. Proponents of the weaker view hold that, while persons are currently the best authorities as to the occurrent contents of their own minds, evidence such as conflicting readings of brain states could eventually override such authority, despite the dependence of the evidence on earlier firstperson reports. Weaker views on privileged access may also deny infallibility on more general grounds. In judging anything, including an occurrent mental state, to have a particular property P, it seems that I must remember which property P is, and memory appears to be always fallible. Even if such judgments are always fallible, however, they may be more immediately justified than other sorts of judgments. Hence there may still be privileged access, but of a weaker sort. In the twentieth century, Ryle attacked the idea of privileged access by analyzing introspection, awareness of what one is thinking or doing, in terms of behavioral dispositions, e.g. dispositions to give memory reports of one’s mental states when asked to do so. But while behaviorist or functional analyses of some states of mind may be plausible, for instance analyses of cognitive states such as beliefs, accounts in these terms of occurrent states such as sensations or images are far less plausible. A more influential attack on stronger versions of privileged access was mounted by Wilfrid Sellars. According to him, we must be trained to report non-inferentially on properties of our sense experience by first learning to respond with whole systems of concepts to public, physical objects. Before I can learn to report a red sense impression, I must learn the system of color concepts and the logical relations among them by learning to respond to colored objects. Hence, knowledge of my own mental states cannot be the firm basis from which I progress to other knowledge.    742 Even if this order of concept acquisition is determined necessarily, it still may be that persons’ access to their own mental states is privileged in some of the ways indicated, once the requisite concepts have been acquired. Beliefs about one’s own occurrent states of mind may still be more immediately justified than beliefs about physical properties, for example. 

pro attitude, a favorable disposition toward an object or state of affairs. Although some philosophers equate pro attitudes with desires, the expression is more often intended to cover a wide range of conative states of mind including wants, feelings, wishes, values, and principles. My regarding a certain course of action open to me as morally required and my regarding it as a source of selfish satisfaction equally qualify as pro attitudes toward the object of that action. It is widely held that intentional action, or, more generally, acting for reasons, is necessarily based, in part, on one or more pro attitudes. If I go to the store in order to buy some turnips, then, in addition to my regarding my store-going as conducive to turnip buying, I must have some pro attitude toward turnip buying. 

probability, a numerical value that can attach to items of various kinds e.g., propositions, events, and kinds of events that is a measure of the degree to which they may or should be expected  or the degree to which they have “their own disposition,” i.e., independently of our psychological expectations  to be true, to occur, or to be exemplified depending on the kind of item the value attaches to. There are both multiple interpretations of probability and two main kinds of theories of probability: abstract formal calculi and interpretations of the calculi. An abstract formal calculus axiomatically characterizes formal properties of probability functions, where the arguments of the function are often thought of as sets, or as elements of a Boolean algebra. In application, the nature of the arguments of a probability function, as well as the meaning of probability, are given by interpretations of probability. The most famous axiomatization is Kolmogorov’s Foundations of the Theory of Probability, 1933. The three axioms for probability functions Pr are: 1 PrX M 0 for all X; 2 PrX % 1 if X is necessary e.g., a tautology if a proposition, a necessary event if an event, and a “universal set” if a set; and 3 PrX 7 Y % PrX ! PrY where ‘7’ can mean, e.g., logical disjunction, or set-theoretical union if X and Y are mutually exclusive X & Y is a contradiction if they are propositions, they can’t both happen if they are events, and their set-theoretical intersection is empty if they are sets. Axiom 3 is called finite additivity, which is sometimes generalized to countable additivity, involving infinite disjunctions of propositions, or infinite unions of sets. Conditional probability, PrX/Y the probability of X “given” or “conditional on” Y, is defined as the quotient PrX & Y/PrY. An item X is said to be positively or negatively statistically or probabilistically correlated with an item Y according to whether PrX/Y is greater than or less than PrX/-Y where -Y is the negation of a proposition Y, or the non-occurrence of an event Y, or the set-theoretical complement of a set Y; in the case of equality, X is said to be statistically or probabilistically independent of Y. All three of these probabilistic relations are symmetric, and sometimes the term ‘probabilistic relevance’ is used instead of ‘correlation’. From the axioms, familiar theorems can be proved: e.g., 4 Pr-X % 1  PrX; 5 PrX 7 Y % PrX ! PrY  PrX & Y for all X and Y; and 6 a simple version of Bayes’s theorem PrX/Y % PrY/XPrX/PrY. Thus, an abstract formal calculus of probability allows for calculation of the probabilities of some items from the probabilities of others. The main interpretations of probability include the classical, relative frequency, propensity, logical, and subjective interpretations. According to the classical interpretation, the probability of an event, e.g. of heads on a coin toss, is equal to the ratio of the number of “equipossibilities” or equiprobable events favorable to the event in question to the total number of relevant equipossibilities. On the relative frequency interpretation, developed by Venn The Logic of Chance, 1866 and Reichenbach The Theory of Probability, pro attitude probability 743    743 1935, probability attaches to sets of events within a “reference class.” Where W is the reference class, and n is the number of events in W, and m is the number of events in or of kind X, within W, then the probability of X, relative to W, is m/n. For various conceptual and technical reasons, this kind of “actual finite relative frequency” interpretation has been refined into various infinite and hypothetical infinite relative frequency accounts, where probability is defined in terms of limits of series of relative frequencies in finite nested populations of increasing sizes, sometimes involving hypothetical infinite extensions of an actual population. The reasons for these developments involve, e.g.: the artificial restriction, for finite populations, of probabilities to values of the form i/n, where n is the size of the reference class; the possibility of “mere coincidence” in the actual world, where these may not reflect the true physical dispositions involved in the relevant events; and the fact that probability is often thought to attach to possibilities involving single events, while probabilities on the relative frequency account attach to sets of events this is the “problem of the single case,” also called the “problem of the reference class”. These problems also have inspired “propensity” accounts of probability, according to which probability is a more or less primitive idea that measures the physical propensity or disposition of a given kind of physical situation to yield an outcome of a given type, or to yield a “long-run” relative frequency of an outcome of a given type. A theorem of probability proved by Jacob Bernoulli Ars Conjectandi, 1713 and sometimes called Bernoulli’s theorem or the weak law of large numbers, and also known as the first limit theorem, is important for appreciating the frequency interpretation. The theorem states, roughly, that in the long run, frequency settles down to probability. For example, suppose the probability of a certain coin’s landing heads on any given toss is 0.5, and let e be any number greater than 0. Then the theorem implies that as the number of tosses grows without bound, the probability approaches 1 that the frequency of heads will be within e of 0.5. More generally, let p be the probability of an outcome O on a trial of an experiment, and assume that this probability remains constant as the experiment is repeated. After n trials, there will be a frequency, f n, of trials yielding outcome O. The theorem says that for any numbers d and e greater than 0, there is an n such that the probability P that _pf n_ ‹ e is within d of 1 P  1d. Bernoulli also showed how to calculate such n for given values of d, e, and p. It is important to notice that the theorem concerns probabilities, and not certainty, for a long-run frequency. Notice also the assumption that the probability p of O remains constant as the experiment is repeated, so that the outcomes on trials are probabilistically independent of earlier outcomes. The kinds of interpretations of probability just described are sometimes called “objective” or “statistical” or “empirical” since the value of a probability, on these accounts, depends on what actually happens, or on what actual given physical situations are disposed to produce  as opposed to depending only on logical relations between the relevant events or propositions, or on what we should rationally expect to happen or what we should rationally believe. In contrast to these accounts, there are the “logical” and the “subjective” interpretations of probability. Carnap “The Two Concepts of Probability,” Philosophy and Phenomenological Research, 1945 has marked this kind of distinction by calling the second concept probability1 and the first probability2. According to the logical interpretation, associated with Carnap  Logical Foundations of Probability, 1950; and Continuum of Inductive Methods, 1952, the probability of a proposition X given a proposition Y is the “degree to which Y logically entails X.” Carnap developed an ingenious and elaborate set of systems of logical probability, including, e.g., separate systems depending on the degree to which one happens to be, logically and rationally, sensitive to new information in the reevaluation of probabilities. There is, of course, a connection between the ideas of logical probability, rationality, belief, and belief revision. It is natural to explicate the “logical-probabilistic” idea of the probability of X given Y as the degree to which a rational person would believe X having come to learn Y taking account of background knowledge. Here, the idea of belief suggests a subjective sometimes called epistemic or partial belief or degree of belief interpretation of probability; and the idea of probability revision suggests the concept of induction: both the logical and the subjective interpretations of probability have been called “inductive probability”  a formal apparatus to characterize rational learning from experience. The subjective interpretation of probability, according to which the probability of a proposition is a measure of one’s degree of belief in it, was developed by, e.g., Ramsey “Truth and Probability,” in his Foundations of Mathematics and Other Essays, 1926; Definetti “Foresight: Its Logical Laws, Its Subjective Sources,” 1937, transprobability probability 744    744 lated by H. Kyburg, Jr., in H. E. Smokler, Studies in Subjective Probability, 1964; and Savage The Foundations of Statistics, 1954. Of course, subjective probability varies from person to person. Also, in order for this to be an interpretation of probability, so that the relevant axioms are satisfied, not all persons can count  only rational, or “coherent” persons should count. Some theorists have drawn a connection between rationality and probabilistic degrees of belief in terms of dispositions to set coherent betting odds those that do not allow a “Dutch book”  an arrangement that forces the agent to lose come what may, while others have described the connection in more general decision-theoretic terms. 

problem of induction. First stated by Hume, this problem concerns the logical basis of inferences from observed matters of fact to unobserved matters of fact. Although discussion often focuses upon predictions of future events e.g., a solar eclipse, the question applies also to inferences to past facts e.g., the extinction of dinosaurs and to present occurrences beyond the range of direct observation e.g., the motions of planets during daylight hours. Long before Hume the ancient Skeptics had recognized that such inferences cannot be made with certainty; they realized there can be no demonstrative deductive inference, say, from the past and present to the future. Hume, however, posed a more profound difficulty: Are we justified in placing any degree of confidence in the conclusions of such inferences? His question is whether there is any type of non-demonstrative or inductive inference in which we can be justified in placing any confidence at all. According to Hume, our inferences from the observed to the unobserved are based on regularities found in nature. We believe, e.g., that the earth, sun, and moon move in regular patterns according to Newtonian mechanics, and on that basis astronomers predict solar and lunar eclipses. Hume notes, however, that all of our evidence for such uniformities consists of past and present experience; in applying these uniformities to the future behavior of these bodies we are making an inference from the observed to the unobserved. This point holds in general. Whenever we make inferences from the observed to the unobserved we rely on the uniformity of nature. The basis for our belief that nature is reasonably uniform is our experience of such uniformity in the past. If we infer that nature will continue to be uniform in the future, we are making an inference from the observed to the unobserved  precisely the kind of inference for which we are seeking a justification. We are thus caught up in a circular argument. Since, as Hume emphasized, much of our reasoning from the observed to the unobserved is based on causal relations, he analyzed causality to ascertain whether it could furnish a necessary connection between distinct events that could serve as a basis for such inferences. His conclusion was negative. We cannot establish any such connection a priori, for it is impossible to deduce the nature of an effect from its cause  e.g., we cannot deduce from the appearance of falling snow that it will cause a sensation of cold rather than heat. Likewise, we cannot deduce the nature of a cause from its effect  e.g., looking at a diamond, we cannot deduce that it was produced by great heat and pressure. All such knowledge is based on past experience. If we infer that future snow will feel cold or that future diamonds will be produced by great heat and pressure, we are again making inferences from the observed to the unobserved. Furthermore, if we carefully observe cases in which we believe a causeeffect relation holds, we cannot perceive any necessary connection between cause and effect, or any power in the cause that brings about the effect. We observe only that an event of one type e.g., drinking water occurs prior to and contiguously with an event of another type quenching thirst. Moreover, we notice that events of the two types have exhibited a constant conjunction; i.e., whenever an event of the first type has occurred in the past it has been followed by one of the second type. We cannot discover any necessary connection or causal power a posteriori; we can only establish priority, contiguity, and constant conjunction up to the present. If we infer that this constant conjunction will persist in future cases, we are making another inference from observed to unobserved cases. To use causality as a basis for justifying inference from the observed to the probability, prior problem of induction 745    745 unobserved would again invovle a circular argument. Hume concludes skeptically that there can be no rational or logical justification of inferences from the observed to the unobserved  i.e., inductive or non-demonstrative inference. Such inferences are based on custom and habit. Nature has endowed us with a proclivity to extrapolate from past cases to future cases of a similar kind. Having observed that events of one type have been regularly followed by events of another type, we experience, upon encountering a case of the first type, a psychological expectation that one of the second type will follow. Such an expectation does not constitute a rational justification. Although Hume posed his problem in terms of homely examples, the issues he raises go to the heart of even the most sophisticated empirical sciences, for all of them involve inference from observed phenomena to unobserved facts. Although complex theories are often employed, Hume’s problem still applies. Its force is by no means confined to induction by simple enumeration. Philosophers have responded to the problem of induction in many different ways. Kant invoked synthetic a priori principles. Many twentieth-century philosophers have treated it as a pseudo-problem, based on linguistic confusion, that requires dissolution rather than solution. Carnap maintained that inductive intuition is indispensable. Reichenbach offered a pragmatic vindication. Goodman has recommended replacing Hume’s “old riddle” with a new riddle of induction that he has posed. Popper, taking Hume’s skeptical arguments as conclusive, advocates deductivism. He argues that induction is unjustifiable and dispensable. None of the many suggestions is widely accepted as correct. 

problem of other minds, the question of what rational basis a person can have for the belief that other persons are similarly conscious and have minds. Every person, by virtue of being conscious, is aware of her own state of consciousness and thus knows she has a mind; but the mental states of others are not similarly apparent to her. An influential attempt to solve this problem was made by philosophical behaviorists. According to Ryle in The Concept of Mind 1949, a mind is not a ghost in the physical machine but roughly speaking an aggregate of dispositions to behave intelligently and to respond overtly to sensory stimulation. Since the behavior distinctive of these mentalistic dispositions is readily observable in other human beings, the so-called problem of other minds is easily solved: it arose from mere confusion about the concept of mind. Ryle’s opponents were generally willing to concede that such dispositions provide proof that another person has a “mind” or is a sentient being, but they were not willing to admit that those dispositions provide proof that other people actually have feelings, thoughts, and sensory experiences. Their convictions on this last matter generated a revised version of the otherminds problem; it might be called the problem of other-person experiences. Early efforts to solve the problem of other minds can be viewed as attempts to solve the problem of other-person experiences. According to J. S. Mill’s Examination of Sir William Hamilton’s Philosophy 1865, one can defend one’s conviction that others have feelings and other subjective experiences by employing an argument from analogy. To develop that analogy one first attends to how one’s own experiences are related to overt or publicly observable phenomena. One might observe that one feels pain when pricked by a pin and that one responds to the pain by wincing and saying “ouch.” The next step is to attend to the behavior and circumstances of others. Since other people are physically very similar to oneself, it is reasonable to conclude that if they are pricked by a pin and respond by wincing and saying “ouch,” they too have felt pain. Analogous inferences involving other sorts of mental states and other sorts of behavior and circumstances add strong support, Mill said, to one’s belief in other-person experiences. Although arguments from analogy are generally conceded to provide rationally acceptable evidence for unobserved phenomena, the analogical argument for other-person experiences was vigorously attacked in the 1960s by philosophers influenced by Wittgenstein’s Philosophical Investigations 1953. Their central contention was that anyone employing the argument must assume that, solely from her own case, she knows what feelings and thoughts are. This assumption was refuted, they thought, by Wittgenstein’s private language argument, which proved that we learn what feelings and thoughts are only in the process of learning a publicly understandable language containing an appropriate psychological vocabulary. To understand this latter vocabulary, these critics said, one must be able to use its ingredient words correctly problem of other minds problem of other minds 746    746 in relation to others as well as to oneself; and this can be ascertained only because words like ‘pain’ and ‘depression’ are associated with behavioral criteria. When such criteria are satisfied by the behavior of others, one knows that the words are correctly applied to them and that one is justified in believing that they have the experiences in question. The supposed problem of other-person experiences is thus “dissolved” by a just appreciation of the preconditions for coherent thought about psychological states. Wittgenstein’s claim that, to be conceivable, “an inner process stands in need of external criteria,” lost its hold on philosophers during the 1970s. An important consideration was this: if a feeling of pain is a genuine reality different from the behavior that typically accompanies it, then so-called pain behavior cannot be shown to provide adequate evidence for the presence of pain by a purely linguistic argument; some empirical inductive evidence is needed. Since, contrary to Wittgenstein, one knows what the feeling of pain is like only by having that feeling, one’s belief that other people occasionally have feelings that are significantly like the pain one feels oneself apparently must be supported by an argument in which analogy plays a central role. No other strategy seems possible. 

problem of the criterion, a problem of epistemology, arising in the attempt both to formulate the criteria and to determine the extent of knowledge. Skeptical and non-skeptical philosophers disagree as to what, or how much, we know. Do we have knowledge of the external world, other minds, the past, and the future? Any answer depends on what the correct criteria of knowledge are. The problem is generated by the seeming plausibility of the following two propositions: 1 In order to recognize instances, and thus to determine the extent, of knowledge, we must know the criteria for it. 2 In order to know the criteria for knowledge i.e., to distinguish between correct and incorrect criteria, we must already be able to recognize its instances. According to an argument of ancient Grecian Skepticism, we can know neither the extent nor the criteria of knowledge because 1 and 2 are both true. There are, however, three further possibilities. First, it might be that 2 is true but 1 false: we can recognize instances of knowledge even if we do not know the criteria of knowledge. Second, it might be that 1 is true but 2 false: we can identify the criteria of knowledge without prior recognition of its instances. Finally, it might be that both 1 and 2 are false. We can know the extent of knowledge without knowing criteria, and vice versa. Chisholm, who has devoted particular attention to this problem, calls the first of these options particularism, and the second methodism. Hume, a skeptic about the extent of empirical knowledge, was a methodist. Reid and Moore were particularists; they rejected Hume’s skepticism on the ground that it turns obvious cases of knowledge into cases of ignorance. Chisholm advocates particularism because he believes that, unless one knows to begin with what ought to count as an instance of knowledge, any choice of a criterion is ungrounded and thus arbitrary. Methodists turn this argument around: they reject as dogmatic any identification of instances of knowledge not based on a criterion. 

problem of the speckled hen: a problem propounded by Ryle as an objection to Ayer’s analysis of perception in terms of sense-data. It is implied by this analysis that, if I see a speckled hen in a good light and so on, I do so by means of apprehending a speckled sense-datum. The analysis implies further that the sense-datum actually has just the number of speckles that I seem to see as I look at the hen, and that it is immediately evident to me just how many speckles this is. Thus, if I seem to see many speckles as I look at the hen, the sense-datum I apprehend must actually contain many speckles, and it must be immediately evident to me how many it does contain. Now suppose it seems to me that I see more than 100 speckles. Then the datum I am apprehending must contain more than 100 speckles. Perhaps it contains 132 of them. The analysis would then imply, absurdly, that it must be immediately evident to me that the number of speckles is exactly 132. One way to avoid this implication would be to deny that a sense-datum of mine could contain exactly 132 speckles  or any other large, determinate number of them  precisely on the ground that it could never seem to me that I was seeing exactly that many speckles. A possible drawback of this approach is that it involves committing oneself to the claim, which some philosophers have found problem of the criterion problem of the speckled hen 747    747 self-contradictory, that a sense-datum may contain many speckles even if there is no large number n such that it contains n speckles. 

process-product ambiguity, an ambiguity that occurs when a noun can refer either to a process or activity or to the product of that process or activity. E.g., ‘The definition was difficult’ could mean either that the activity of defining was a difficult one to perform, or that the definiens the form of words proposed as equivalent to the term being defined that the definer produced was difficult to understand. Again, ‘The writing absorbed her attention’ leaves it unclear whether it was the activity of writing or a product of that activity that she found engrossing. Philosophically significant terms that might be held to exhibit processproduct ambiguity include: ‘analysis’, ‘explanation’, ‘inference’, ‘thought’. P.Mac. process theology, any theology strongly influenced by the theistic metaphysics of Whitehead or Hartshorne; more generally, any theology that takes process or change as basic characteristics of all actual beings, including God. Those versions most influenced by Whitehead and Hartshorne share a core of convictions that constitute the most distinctive theses of process theology: God is constantly growing, though certain abstract features of God e.g., being loving remain constant; God is related to every other actual being and is affected by what happens to it; every actual being has some self-determination, and God’s power is reconceived as the power to lure attempt to persuade each actual being to be what God wishes it to be. These theses represent significant differences from ideas of God common in the tradition of Western theism, according to which God is unchanging, is not really related to creatures because God is not affected by what happens to them, and has the power to do whatever it is logically possible for God to do omnipotence. Process theologians also disagree with the idea that God knows the future in all its details, holding that God knows only those details of the future that are causally necessitated by past events. They claim these are only certain abstract features of a small class of events in the near future and of an even smaller class in the more distant future. Because of their understanding of divine power and their affirmation of creaturely self-determination, they claim that they provide a more adequate theodicy. Their critics claim that their idea of God’s power, if correct, would render God unworthy of worship; some also make this claim about their idea of God’s knowledge, preferring a more traditional idea of omniscience. Although Whitehead and Hartshorne were both philosophers rather than theologians, process theology has been more influential among theologians. It is a major current in contemporary American Protestant theology and has attracted the attention of some Roman Catholic theologians as well. It also has influenced some biblical scholars who are attempting to develop a distinctive process hermeneutics.

production theory, the economic theory dealing with the conversion of factors of production into consumer goods. In capitalistic theories that assume ideal markets, firms produce goods from three kinds of factors: capital, labor, and raw materials. Production is subject to the constraint that profit the difference between revenues and costs be maximized. The firm is thereby faced with the following decisions: how much to produce, what price to charge for the product, what proportions to combine the three kinds of factors in, and what price to pay for the factors. In markets close to perfect competition, the firm will have little control over prices so the decision problem tends to reduce to the amounts of factors to use. The range of feasible factor combinations depends on the technologies available to firms. Interesting complications arise if not all firms have access to the same technologies, or if not all firms make accurate responses concerning technological changes. Also, if the scale of production affects the feasible technologies, the firms’ decision process must be subtle. In each of these cases, imperfect competition will result. Marxian economists think that the concepts used in this kind of production theory have a normative component. In reality, a large firm’s capital tends to be owned by a rather small, privileged class of non-laborers and labor is treated as a commodity like any other factor. This might proceduralism production theory 748    748 lead to the perception that profit results primarily from capital and, therefore, belongs to its owners. Marxians contend that labor is primarily responsible for profit and, consequently, that labor is entitled to more than the market wage. 

professional ethics, a term designating one or more of 1 the justified moral values that should govern the work of professionals; 2 the moral values that actually do guide groups of professionals, whether those values are identified as a principles in codes of ethics promulgated by professional societies or b actual beliefs and conduct of professionals; and 3 the study of professional ethics in the preceding senses, either i normative philosophical inquiries into the values desirable for professionals to embrace, or ii descriptive scientific studies of the actual beliefs and conduct of groups of professionals. Professional values include principles of obligation and rights, as well as virtues and personal moral ideals such as those manifested in the lives of Jane Addams, Albert Schweitzer, and Thurgood Marshall. Professions are defined by advanced expertise, social organizations, society-granted monopolies over services, and especially by shared commitments to promote a distinctive public good such as health medicine, justice law, or learning education. These shared commitments imply special duties to make services available, maintain confidentiality, secure informed consent for services, and be loyal to clients, employers, and others with whom one has fiduciary relationships. Both theoretical and practical issues surround these duties. The central theoretical issue is to understand how the justified moral values governing professionals are linked to wider values, such as human rights. Most practical dilemmas concern how to balance conflicting duties. For example, what should attorneys do when confidentiality requires keeping information secret that might save the life of an innocent third party? Other practical issues are problems of vagueness and uncertainty surrounding how to apply duties in particular contexts. For example, does respect for patients’ autonomy forbid, permit, or require a physician to assist a terminally ill patient desiring suicide? Equally important is how to resolve conflicts of interest in which self-seeking places moral values at risk. 

proof by recursion, also called proof by mathematical induction, a method for conclusively demonstrating the truth of universal propositions about the natural numbers. The system of natural numbers is construed as an infinite sequence of elements beginning with the number 1 and such that each subsequent element is the immediate successor of the preceding element. The immediate successor of a number is the sum of that number with 1. In order to apply this method to show that every number has a certain chosen property it is necessary to demonstrate two subsidiary propositions often called respectively the basis step and the inductive step. The basis step is that the number 1 has the chosen property; the inductive step is that the successor of any number having the chosen property is also a number having the chosen property in other words, for every number n, if n has the chosen property then the successor of n also has the chosen property. The inductive step is itself a universal proposition that may have been proved by recursion. The most commonly used example of a theorem proved by recursion is the remarkable fact, known before the time of Plato, that the sum of the first n odd numbers is the square of n. This proposition, mentioned prominently by Leibniz as requiring and having demonstrative proof, is expressed in universal form as follows: for every number n, the sum of the first n odd numbers is n2. 1 % 12, 1 ! 3 % 22, 1 ! 3 ! 5 % 32, and so on. Rigorous formulation of a proof by recursion productive reason proof by recursion 749    749 often uses as a premise the proposition called, since the time of De Morgan, the principle of mathematical induction: every property belonging to 1 and belonging to the successor of every number to which it belongs is a property that belongs without exception to every number. Peano 18581932 took the principle of mathematical induction as an axiom in his 1889 axiomatization of arithmetic or the theory of natural numbers. The first acceptable formulation of this principle is attributed to Pascal. 

proof theory, a branch of mathematical logic founded by David Hilbert in the 1920s to pursue Hilbert’s Program. The foundational problems underlying that program had been formulated around the turn of the century, e.g., in Hilbert’s famous address to the International Congress of Mathematicians in Paris 1900. They were closely connected with investigations on the foundations of analysis carried out by Cantor and Dedekind; but they were also related to their conflict with Kronecker on the nature of mathematics and to the difficulties of a completely unrestricted notion of set or multiplicity. At that time, the central issue for Hilbert was the consistency of sets in Cantor’s sense. He suggested that the existence of consistent sets multiplicities, e.g., that of real numbers, could be secured by proving the consistency of a suitable, characterizing axiomatic system; but there were only the vaguest indications on how to do that. In a radical departure from standard practice and his earlier hints, Hilbert proposed four years later a novel way of attacking the consistency problem for theories in Über die Grundlagen der Logik und der Arithmetik 1904. This approach would require, first, a strict formalization of logic together with mathematics, then consideration of the finite syntactic configurations constituting the joint formalism as mathematical objects, and showing by mathematical arguments that contradictory formulas cannot be derived. Though Hilbert lectured on issues concerning the foundations of mathematics during the subsequent years, the technical development and philosophical clarification of proof theory and its aims began only around 1920. That involved, first of all, a detailed description of logical calculi and the careful development of parts of mathematics in suitable systems. A record of the former is found in Hilbert and Ackermann, Grundzüge der theoretischen Logik 1928; and of the latter in Supplement IV of Hilbert and Bernays, Grundlagen der Mathematik II 1939. This presupposes the clear distinction between metamathematics and mathematics introduced by Hilbert. For the purposes of the consistency program metamathematics was now taken to be a very weak part of arithmetic, so-called finitist mathematics, believed to correspond to the part of mathematics that was accepted by constructivists like Kronecker and Brouwer. Additional metamathematical issues concerned the completeness and decidability of theories. The crucial technical tool for the pursuit of the consistency problem was Hilbert’s e-calculus. The metamathematical problems attracted the collaboration of young and quite brilliant mathematicians with philosophical interests; among them were Paul Bernays, Wilhelm Ackermann, John von Neumann, Jacques Herbrand, Gerhard Gentzen, and Kurt Schütte. The results obtained in the 1920s were disappointing when measured against the hopes and ambitions: Ackermann, von Neumann, and Herbrand established essentially the consistency of arithmetic with a very restricted principle of induction. That limits of finitist considerations for consistency proofs had been reached became clear in 1931 through Gödel’s incompleteness theorems. Also, special cases of the decision problem for predicate logic Hilbert’s Entscheidungsproblem had been solved; its general solvability was made rather implausible by some of Gödel’s results in his 1931 paper. The actual proof of unsolvability had to wait until 1936 for a conceptual clarification of ‘mechanical procedure’ or ‘algorithm’; that was achieved through the work of Church and Turing. The further development of proof theory is roughly characterized by two complementary tendencies: 1 the extension of the metamathematical frame relative to which “constructive” consistency proofs can be obtained, and 2 the refined formalization of parts of mathematics in theories much weaker than set theory or even full second-order arithmetic. The former tendency started with the work of Gödel and Gentzen in 1933 establishing the consistency of full classical arithmetic relative to intuitionistic arithmetic; it led in the 1970s and 1980s to consistency proofs of strong subsystems of secondorder arithmetic relative to intuitionistic theories of constructive ordinals. The latter tendency reaches back to Weyl’s book Das Kontinuum 1918 and culminated in the 1970s by showing proof-theoretic reflection principles proof theory 750    750 that the classical results of mathematical analysis can be formally obtained in conservative extensions of first-order arithmetic. For the metamathematical work Gentzen’s introduction of sequent calculi and the use of transfinite induction along constructive ordinals turned out to be very important, as well as Gödel’s primitive recursive functionals of finite type. The methods and results of proof theory are playing, not surprisingly, a significant role in computer science. Work in proof theory has been motivated by issues in the foundations of mathematics, with the explicit goal of achieving epistemological reductions of strong theories for mathematical practice like set theory or second-order arithmetic to weak, philosophically distinguished theories like primitive recursive arithmetic. As the formalization of mathematics in strong theories is crucial for the metamathematical approach, and as the programmatic goal can be seen as a way of circumventing the philosophical issues surrounding strong theories, e.g., the nature of infinite sets in the case of set theory, Hilbert’s philosophical position is often equated with formalism  in the sense of Frege in his Über die Grundlagen der Geometrie 190306 and also of Brouwer’s inaugural address Intuitionism and Formalism 1912. Though such a view is not completely unsupported by some of Hilbert’s polemical remarks during the 1920s, on balance, his philosophical views developed into a sophisticated instrumentalism, if that label is taken in Ernest Nagel’s judicious sense The Structure of Science, 1961. Hilbert’s is an instrumentalism emphasizing the contentual motivation of mathematical theories; that is clearly expressed in the first chapter of Hilbert and Bernays’s Grundlagen der Mathematik I 1934. A sustained philosophical analysis of proof-theoretic research in the context of broader issues in the philosophy of mathematics was provided by Bernays; his penetrating essays stretch over five decades and have been collected in Abhandlungen zur Philosophie der Mathematik 1976. 

propensity, an irregular or non-necessitating causal disposition of an object or system to produce some result or effect. Propensities are usually conceived as essentially probabilistic in nature. A die may be said to have a propensity of “strength” or magnitude 1 /6 to turn up a 3 if thrown from a dice box, of strength 1 /3 to turn up, say, a 3 or 4, etc. But propensity talk is arguably appropriate only when determinism fails. Strength is often taken to vary from 0 to 1. Popper regarded the propensity notion as a new physical or metaphysical hypothesis, akin to that of forces. Like Peirce, he deployed it to interpret probability claims about single cases: e.g., the probability of this radium atom’s decaying in 1,600 years is 1 /2. On relative frequency interpretations, probability claims are about properties of large classes such as relative frequencies of outcomes in them, rather than about single cases. But single-case claims appear to be common in quantum theory. Popper advocated a propensity interpretation of quantum theory. Propensities also feature in theories of indeterministic or probabilistic causation. Competing theories about propensities attribute them variously to complex systems such as chance or experimental set-ups or arrangements a coin and tossing device, to entities within such set-ups the coin itself, and to particular trials of such set-ups. Long-run theories construe propensities as dispositions to give rise to certain relative frequencies of, or probability distributions over, outcomes in long runs of trials, which are sometimes said to “manifest” or “display” the propensities. Here a propensity’s strength is identical to some such frequency. By contrast, single-case theories construe propensities as dispositions of singular trials to bring about particular outcomes. Their existence, not their strength, is displayed by such an outcome. Here frequencies provide evidence about propensity strength. But the two can always differ; they converge with a limiting probability of 1 in an appropriate long run. 

property, roughly, an attribute, characteristic, feature, trait, or aspect. propensity property 751    751 Intensionality. There are two salient ways of talking about properties. First, as predicables or instantiables. For example, the property red is predicable of red objects; they are instances of it. Properties are said to be intensional entities in the sense that distinct properties can be truly predicated of i.e., have as instances exactly the same things: the property of being a creature with a kidney & the property of being a creature with a heart, though these two sets have the same members. Properties thus differ from sets collections, classes; for the latter satisfy a principle of extensionality: they are identical if they have the same elements. The second salient way of talking about properties is by means of property abstracts such as ‘the property of being F’. Such linguistic expressions are said to be intensional in the following semantical vs. ontological sense: ‘the property of being F’ and ‘the property of being G’ can denote different properties even though the predicates ‘F’ and ‘G’ are true of exactly the same things. The standard explanation Frege, Russell, Carnap, et al. is that ‘the property of being F’ denotes the property that the predicate ‘F’ expresses. Since predicates ‘F’ and ‘G’ can be true of the same things without being synonyms, the property abstracts ‘being F’ and ‘being G’ can denote different properties. Identity criteria. Some philosophers believe that properties are identical if they necessarily have the same instances. Other philosophers hold that this criterion of identity holds only for a special subclass of properties  those that are purely qualitative  and that the properties for which this criterion does not hold are all “complex” e.g., relational, disjunctive, conditional, or negative properties. On this theory, complex properties are identical if they have the same form and their purely qualitative constituents are identical. Ontological status. Because properties are a kind of universal, each of the standard views on the ontological status of universals has been applied to properties as a special case. Nominalism: only particulars and perhaps collections of particulars exist; therefore, either properties do not exist or they are reducible following Carnap et al. to collections of particulars including perhaps particulars that are not actual but only possible. Conceptualism: properties exist but are dependent on the mind. Realism: properties exist independently of the mind. Realism has two main versions. In rebus realism: a property exists only if it has instances. Ante rem realism: a property can exist even if it has no instances. For example, the property of being a man weighing over ton has no instances; however, it is plausible to hold that this property does exist. After all, this property seems to be what is expressed by the predicate ‘is a man weighing over a ton’. Essence and accident. The properties that a given entity has divide into two disjoint classes: those that are essential to the entity and those that are accidental to it. A property is essential to an entity if, necessarily, the entity cannot exist without being an instance of the property. A property is accidental to an individual if it is possible for the individual to exist without being an instance of the property. Being a number is an essential property of nine; being the number of the planets is an accidental property of nine. Some philosophers believe that all properties are either essential by nature or accidental by nature. A property is essential by nature if it can be an essential property of some entity and, necessarily, it is an essential property of each entity that is an instance of it. The property of being self-identical is thus essential by nature. However, it is controversial whether every property that is essential to something must be essential by nature. The following is a candidate counterexample. If this automobile backfires loudly on a given occasion, loudness would seem to be an essential property of the associated bang. That particular bang could not exist without being loud. If the automobile had backfired softly, that particular bang would not have existed; an altogether distinct bang  a soft bang  would have existed. By contrast, if a man is loud, loudness is only an accidental property of him; he could exist without being loud. Loudness thus appears to be a counterexample: although it is an essential property of certain particulars, it is not essential by nature. It might be replied echoing Aristotle that a loud bang and a loud man instantiate loudness in different ways and, more generally, that properties can be predicated instantiated in different ways. If so, then one should be specific about which kind of predication instantiation is intended in the definition of ‘essential by nature’ and ‘accidental by nature’. When this is done, the counterexamples might well disappear. If there are indeed different ways of being predicated instantiated, most of the foregoing remarks about intensionality, identity criteria, and the ontological status of properties should be refined accordingly. 

proposition, an abstract object said to be that to which a person is related by a belief, desire, or other psychological attitude, typically expressed in language containing a psychological verb ‘think’, ‘deny’, ‘doubt’, etc. followed by a thatclause. The psychological states in question are called propositional attitudes. When I believe that snow is white I stand in the relation of believing to the proposition that snow is white. When I hope that the protons will not decay, hope relates me to the proposition that the protons will not decay. A proposition can be a common object for various attitudes of various agents: that the protons will not decay can be the object of my belief, my hope, and your fear. A sentence expressing an attitude is also taken to express the associated proposition. Because ‘The protons will not decay’ identifies my hope, it identifies the proposition to which my hope relates me. Thus the proposition can be the shared meaning of this sentence and all its synonyms, in English or elsewhere e.g., ‘die Protonen werden nicht zerfallen’. This, in sum, is the traditional doctrine of propositions. Although it seems indispensable in some form  for theorizing about thought and language, difficulties abound. Some critics regard propositions as excess baggage in any account of meaning. But unless this is an expression of nominalism, it is confused. Any systematic theory of meaning, plus an apparatus of sets or properties will let us construct proposition-like objects. The proposition a sentence S expresses might, e.g., be identified with a certain set of features that determines S’s meaning. Other sentences with these same features would then express the same proposition. A natural way to associate propositions with sentences is to let the features in question be semantically significant features of the words from which sentences are built. Propositions then acquire the logical structures of sentences: they are atomic, conditional, existential, etc. But combining the view of propositions as meanings with the traditional idea of propositions as bearers of truthvalues brings trouble. It is assumed that two sentences that express the same proposition have the same truth-value indeed, that sentences have their truth-values in virtue of the propositions they express. Yet if propositions are also meanings, this principle fails for sentences with indexical elements: although ‘I am pale’ has a single meaning, two utterances of it can differ in truth-value. In response, one may suggest that the proposition a sentence S expresses depends both on the linguistic meaning of S and on the referents of S’s indexical elements. But this reveals that proposition is a quite technical concept  and one that is not motivated simply by a need to talk about meanings. Related questions arise for propositions as the objects of propositional attitudes. My belief that I am pale may be true, yours that you are pale false. So our beliefs should take distinct propositional objects. Yet we would each use the same sentence, ‘I am pale’, to express our belief. Intuitively, your belief and mine also play similar cognitive roles. We may each choose the sun exposure, clothing, etc., that we take to be appropriate to a fair complexion. So our attitudes seem in an important sense to be the same  an identity that the assignment of distinct propositional objects hides. Apparently, the characterization of beliefs e.g. as being propositional attitudes is at best one component of a more refined, largely unknown account. Quite apart from complications about indexicality, propositions inherit standard difficulties about meaning. Consider the beliefs that Hesperus is a planet and that Phosphorus is a planet. It seems that someone might have one but not the other, thus that they are attitudes toward distinct propositions. This difference apparently reflects the difference in meaning between the sentences ‘Hesperus is a planet’ and ‘Phosphorus is a planet’. The principle would be that non-synonymous sentences express distinct propositions. But it is unclear what makes for a difference in meaning. Since the sentences agree in logico-grammatical structure and in the refer   753 proposition, maximal propositional opacity 754 ents of their terms, their specific meanings must depend on some more subtle feature that has resisted definition. Hence our concept of proposition is also only partly defined. Even the idea that the sentences here express the same proposition is not easily refuted. What such difficulties show is not that the concept of proposition is invalid but that it belongs to a still rudimentary descriptive scheme. It is too thoroughly enmeshed with the concepts of meaning and belief to be of use in solving their attendant problems. This observation is what tends, through a confusion, to give rise to skepticism about propositions. One may, e.g., reasonably posit structured abstract entities  propositions  that represent the features on which the truth-values of sentences depend. Then there is a good sense in which a sentence is true in virtue of the proposition it expresses. But how does the use of words in a certain context associate them with a particular proposition? Lacking an answer, we still cannot explain why a given sentence is true. Similarly, one cannot explain belief as the acceptance of a proposition, since only a substantive theory of thought would reveal how the mind “accepts” a proposition and what it does to accept one proposition rather than another. So a satisfactory doctrine of propositions remains elusive. 

propositional function, an operation that, when applied to something as argument or to more than one thing in a given order as arguments, yields a truth-value as the value of that function for that argument or those arguments. This usage presupposes that truth-values are objects. A function may be singulary, binary, ternary, etc. A singulary propositional function is applicable to one thing and yields, when so applied, a truth-value. For example, being a prime number, when applied to the number 2, yields truth; negation, when applied to truth, yields falsehood. A binary propositional function is applicable to two things in a certain order and yields, when so applied, a truth-value. For example, being north of when applied to New York and Boston in that order yields falsehood. Material implication when applied to falsehood and truth in that order yields truth. The term ‘propositional function’ has a second use, to refer to an operation that, when applied to something as argument or to more than one thing in a given order as arguments, yields a proposition as the value of the function for that argument or those arguments. For example, being a prime number when applied to 2 yields the proposition that 2 is a prime number. Being north of, when applied to New York and Boston in that order, yields the proposition that New York is north of Boston. This usage presupposes that propositions are objects. In a third use, ‘propositional function’ designates a sentence with free occurrences of variables. Thus, ‘x is a prime number’, ‘It is not the case that p’, ‘x is north of y’ and ‘if p then q’ are propositional functions in this sense. C.S. propositional justification.

propositional opacity, failure of a clause to express any particular proposition especially due to the occurrence of pronouns or demonstratives. If having a belief about an individual involves a relation to a proposition, and if a part of the proposition is a way of representing the individual, then belief characterizations that do not indicate the believer’s way of representing the individual could be called propositionally opaque. They do not show all of the propositional elements. For example, ‘My son’s clarinet teacher believes that he should try the bass drum’ would be propositionally opaque because ‘he’ does not indicate how my son John’s teacher represents John, e.g. as his student, as my son, as the boy now playing, etc. This characterization of the example is not appropriate if propositions are as Russell conceived them, sometimes containing the individuals themselves as constituents, because then the propositional constituent John has been referred to. Generally, a characterization of a propositional    754 attitude is propositionally opaque if the expressions in the embedded clause do not refer to the propositional constituents. It is propositionally transparent if the expressions in the embedded clause do so refer. As a rule, referentially opaque contexts are used in propositionally transparent attributions if the referent of a term is distinct from the corresponding propositional constituent. 

proprietates terminorum Latin, ‘properties of terms’, in medieval logic from the twelfth century on, a cluster of semantic properties possessed by categorematic terms. For most authors, these properties apply only when the terms occur in the context of a proposition. The list of such properties and the theory governing them vary from author to author, but always include 1 suppositio. Some authors add 2 appellatio ‘appellating’, ‘naming’, ‘calling’, often not sharply distinguishing from suppositio, the property whereby a term in a certain proposition names or is truly predicable of things, or in some authors of presently existing things. Thus ‘philosophers’ in ‘Some philosophers are wise’ appellates philosophers alive today. 3 Ampliatio ‘ampliation’, ‘broadening’, whereby a term refers to past or future or merely possible things. The reference of ‘philosophers’ is ampliated in ‘Some philosophers were wise’. 4 Restrictio ‘restriction’, ‘narrowing’, whereby the reference of a term is restricted to presently existing things ‘philosophers’ is so restricted in ‘Some philosophers are wise’, or otherwise narrowed from its normal range ‘philosophers’ in ‘Some Grecian philosophers were wise’. 5 Copulatio ‘copulation’, ‘coupling’, which is the type of reference adjectives have ‘wise’ in ‘Some philosophers are wise’, or alternatively the semantic function of the copula. Other meanings too are sometimes given to these terms, depending on the author. Appellatio especially was given a wide variety of interpretations. In particular, for Buridan and other fourteenth-century Continental authors, appellatio means ‘connotation’. Restrictio and copulatio tended to drop out of the literature, or be treated only perfunctorily, after the thirteenth century. 

proprium, one of Porphyry’s five predicables, often translated as ‘property’ or ‘attribute’; but this should not be confused with the broad modern sense in which any feature of a thing may be said to be a property of it. A proprium is a nonessential peculiarity of a species. There are no propria of individuals or genera generalissima, although they may have other uniquely identifying features. A proprium necessarily holds of all members of its species and of nothing else. It is not mentioned in a real definition of the species, and so is not essential to it. Yet it somehow follows from the essence or nature expressed in the real definition. The standard example is risibility the ability to laugh as a proprium of the species man. The real definition of ‘man’ is ‘rational animal’. There is no mention of any ability to laugh. Nevertheless anything that can laugh has both the biological apparatus to produce the sounds and so is an animal and also a certain wit and insight into humor and so is rational. Conversely, any rational animal will have both the vocal chords and diaphragm required for laughing since it is an animal, although the inference may seem too quick and also the mental wherewithal to see the point of a joke since it is rational. Thus any rational animal has what it takes to laugh. In short, every man is risible, and conversely, but risibility is not an essential feature of man. 

protocol statement, one of the statements that constitute the foundations of empirical knowledge. The term was introduced by proponents of foundationalism, who were convinced that in order to avoid the most radical skepticism, one propositional operator protocol statement 755    755 must countenance beliefs that are justified but not as a result of an inference. If all justified beliefs are inferentially justified, then to be justified in believing one proposition P on the basis of another, E, one would have to be justified in believing both E and that E confirms P. But if all justification were inferential, then to be justified in believing E one would need to infer it from some other proposition one justifiably believes, and so on ad infinitum. The only way to avoid this regress is to find some statement knowable without inferring it from some other truth. Philosophers who agree that empirical knowledge has foundations do not necessarily agree on what those foundations are. The British empiricists restrict the class of contingent protocol statements to propositions describing the contents of mind sensations, beliefs, fears, desires, and the like. And even here a statement describing a mental state would be a protocol statement only for the person in that state. Other philosophers, however, would take protocol statements to include at least some assertions about the immediate physical environment. The plausibility of a given candidate for a protocol statement depends on how one analyzes non-inferential justification. Some philosophers rely on the idea of acquaintance. One is non-inferentially justified in believing something when one is directly acquainted with what makes it true. Other philosophers rely on the idea of a state that is in some sense self-presenting. Still others want to understand the notion in terms of the inconceivability of error. The main difficulty in trying to defend a coherent conception of non-inferential justification is to find an account of protocol statements that gives them enough conceptual content to serve as the premises of arguments, while avoiding the charge that the application of concepts always brings with it the possibility of error and the necessity of inference. 

prototype theory, a theory according to which human cognition involves the deployment of “categories” organized around stereotypical exemplars. Prototype theory differs from traditional theories that take the concepts with which we think to be individuated by means of boundary-specifying necessary and sufficient conditions. Advocates of prototypes hold that our concept of bird, for instance, consists in an indefinitely bounded conceptual “space” in which robins and sparrows are central, and chickens and penguins are peripheral  though the category may be differently organized in different cultures or groups. Rather than being all-ornothing, category membership is a matter of degree. This conception of categories was originally inspired by the notion, developed in a different context by Wittgenstein, of family resemblance. Prototypes were first discussed in detail and given empirical credibility in the work of Eleanor Rosch see, e.g., “On the Internal Structure of Perceptual and Semantic Categories,” 1973. 

Proudhon, Pierre-Joseph 180965, French socialist theorist and father of anarchism. He became well known following the publication of What Is Property? 1840, the work containing his main ideas. He argued that the owner of the means of production deprives the workers of a part of their labor: “property is theft.” In order to enable each worker to dispose of his labor, capital and largescale property must be limited. The need to abolish large-scale private property surpassed the immediate need for a state as a controlling agent over chaotic social relationships. To this end he stressed the need for serious reforms in the exchange system. Since the economy and society largely depended on the credit system, Proudhon advocated establishing popular banks that would approve interest-free loans to the poor. Such a mutualism would start the transformation of the actual into a just and nonexploited society of free individuals. Without class antagonism and political authorities, such a society would tend toward an association of communal and industrial collectivities. It would move toward a flexible world federation based on self-management. The main task of social science, then, is to make manifest this immanent logic of social processes. Proudhon’s ideas influenced anarchists, populists Bakunin, Herzen, and syndicalists Jaurès. His conception of self-management was an important inspiration for the later concept of soviets councils. He criticized the inequalities of the contemporary society from the viewpoint of small producers and peasants. Although eclectic and theoretically rather naive, his work attracted the serious attention of his contemporaries and led to a strong attack by Marx in The Holy Family and The Poverty of Philosophy.

pseudo-hallucination, a non-deceptive hallucination. An ordinary hallucination might be thought to comprise two components: i a sensory component, whereby one experiences an image or sensory episode similar in many respects to a veridical perceiving except in being non-veridical; and ii a cognitive component, whereby one takes or is disposed to take the image or sensory episode to be veridical. A pseudohallucination resembles a hallucination, but lacks this second component. In experiencing a pseudohallucination, one appreciates that one is not perceiving veridically. The source of the term seems to be the painter Wassily Kandinsky, who employed it in 1885 to characterize a series of apparently drug-induced images experienced and pondered by a friend who recognized them, at the very time they were occurring, not to be veridical. Kandinsky’s account is discussed by Jaspers in his General Psychopathology, 1916, and thereby entered the clinical lore. Pseudohallucinations may be brought on by the sorts of pathological condition that give rise to hallucinations, or by simple fatigue, emotional adversity, or loneliness. Thus, a driver, late at night, may react to non-existent objects or figures on the road, and immediately recognize his error. 

psycholinguistics, an interdisciplinary research area that uses theoretical descriptions of language taken from linguistics to investigate psychological processes underlying language production, perception, and learning. There is considerable disagreement as to the appropriate characterization of the field and the major problems. Philosophers discussed many of the problems now studied in psycholinguistics before either psychology or linguistics were spawned, but the self-consciously interdisciplinary field combining psychology and linguistics emerged not long after the birth of the two disciplines. Meringer used the adjective ‘psycholingisch-linguistische’ in an 1895 book. Various national traditions of psycholinguistics continued at a steady but fairly low level of activity through the 1920s and declined somewhat during the 1930s and 1940s because of the antimentalist attitudes in both linguistics and psychology. Psycholinguistic researchers in the USSR, mostly inspired by L. S. Vygotsky Thought and Language, 1934, were more active during this period in spite of official suppression. Numerous quasi-independent sources contributed to the rebirth of psycholinguistics in the 1950s; the most significant was a seminar held at Indiana  during the summer of 1953 that led to the publication of Psycholinguistics: A Survey of Theory and Research Problems 1954, edited by C. E. Osgood and T. A. Sebeok  a truly interdisciplinary book jointly written by more than a dozen authors. The contributors attempted to analyze and reconcile three disparate approaches: learning theory from psychology, descriptive linguistics, and information theory which came mainly from engineering. The book had a wide impact and led to many further investigations, but the nature of the field changed rapidly soon after its publication with the Chomskyan revolution in linguistics and the cognitive turn in psychology. The two were not unrelated: Chomsky’s positive contribution, Syntactic Structures, was less broadly influential than his negative review Language, 1959 of B. F. Skinner’s Verbal Behavior. Against the empiricist-behaviorist view of language understanding and production, in which language is merely the exhibition of a more complex form of behavior, Chomsky argued the avowedly rationalist position that the ability to learn and use language is innate and unique to humans. He emphasized the creative aspect of language, that almost all sentences one hears or produces are novel. One of his premises was the alleged infinity of sentences in natural languages, but a less controversial argument can be given: there are tens of millions of five-word sentences in English, all of which are readily understood by speakers who have never heard them. Chomsky’s work promised the possibility of uncovering a very special characteristic of the human mind. But the promise was qualified by the disclaimer that linguistic theory describes only the competence of the ideal speaker. Many psycholinguists spent countless hours during the 1960s and 1970s seeking the traces of underlying competence beneath the untidy performances of actual speakers. During the 1970s, as Chomsky frequently revised his theories of syntax and semantics in significant ways, and numerous alternative linprovability predicate psycholinguistics 757    757 guistic models were under consideration, psychologists generated a range of productive research problems that are increasingly remote from the Chomskyan beginnings. Contemporary psycholinguistics addresses phonetic, phonological, syntactic, semantic, and pragmatic influences on language processing. Few clear conclusions of philosophical import have been established. For example, several decades of animal research have shown that other species can use significant portions of human language, but controversy abounds over how central those portions are to language. Studies now clearly indicate the importance of word frequency and coarticulation, the dependency of a hearer’s identification of a sound as a particular phoneme, or of a visual pattern as a particular letter, not only on the physical features of the pattern but on the properties of other patterns not necessarily adjacent. Physically identical patterns may be heard as a d in one context and a t in another. It is also accepted that at least some of the human lignuistic abilities, particularly those involved in reading and speech perception, are relatively isolated from other cognitive processes. Infant studies show that children as young as eight months learn statistically important patterns characteristic of their natural language  suggesting a complex set of mechanisms that are automatic and invisible to us. 

Pufendorf, Samuel 163294, German historian and theorist of natural law. Pufendorf was influenced by both Grotius and Hobbes. He portrayed people as contentious and quarrelsome, yet as needing one another’s company and assistance. Natural law shows how people can live with one another while pursuing their own conflicting projects. To minimize religious disputes about morals, Pufendorf sought a way of deriving laws of nature from observable facts alone. Yet he thought divine activity essential to morality. He opened his massive Latin treatise On the Law of Nature and of Nations 1672 with a voluntarist account of God’s creation of the essence of mankind: given that we have the nature God gave us, certain laws must be valid for us, but only God’s will determined our nature. As a result, our nature indicates God’s will for us. Hence observable facts about ourselves show us what laws God commands us to obey. Because we so obviously need one another’s assistance, the first law is to increase our sociability, i.e. our willingness to live together. All other laws indicate acts that would bring about this end. In the course of expounding the laws he thought important for the development of social life to the high cultural level our complex nature points us toward, Pufendorf analyzed all the main points that a full legal system must cover. He presented the rudiments of laws of marriage, property, inheritance, contract, and international relations in both war and peace. He also developed the Grotian theory of personal rights, asserting for the first time that rights are pointless unless for each right there are correlative duties binding on others. Taking obligation as his fundamental concept, he developed an imporpsychological behaviorism Pufendorf, Samuel 758    758 punishment Putnam, Hilary 759 tant distinction between perfect and imperfect duties and rights. And in working out a theory of property he suggested the first outlines of a historical sociology of wealth later developed by Adam Smith. Pufendorf’s works on natural law were textbooks for all of Europe for over a century and were far more widely read than any other treatments of the subject. 

punishment, a distinctive form of legal sanction, distinguished first by its painful or unpleasant nature to the offender, and second by the ground on which the sanction is imposed, which must be because the offender offended against the norms of a society. None of these three attributes is a strictly necessary condition for proper use of the word ‘punishment’. There may be unpleasant consequences visited by nature upon an offender such that he might be said to have been “punished enough”; the consequences in a given case may not be unpleasant to a particular offender, as in the punishment of a masochist with his favorite form of self-abuse; and punishment may be imposed for reasons other than offense against society’s norms, as is the case with punishment inflicted in order to deter others from like acts. The “definitional stop” argument in discussions of punishment seeks to tie punishment analytically to retributivism. Retributivism is the theory that punishment is justified by the moral desert of the offender; on this view, a person who culpably does a wrongful action deserves punishment, and this desert is a sufficient as well as a necessary condition of just punishment. Punishment of the deserving, on this view, is an intrinsic good that does not need to be justified by any other good consequences such punishment may achieve, such as the prevention of crime. Retributivism is not to be confused with the view that punishment satisfies the feelings of vengeful citizens nor with the view that punishment preempts such citizens from taking the law into their own hands by vigilante action  these latter views being utilitarian. Retributivism is also not the view sometimes called “weak” or “negative” retributivism that only the deserving are to be punished, for desert on such a view typically operates only as a limiting and not as a justifying condition of punishment. The thesis known as the “definitional stop” says that punishment must be retributive in its justification if it is to be punishment at all. Bad treatment inflicted in order to prevent future crime is not punishment but deserves another name, usually ‘telishment’. The dominant justification of non-retributive punishment or telishment is deterrence. The good in whose name the bad of punishing is justified, on this view, is prevention of future criminal acts. If punishment is inflicted to prevent the offender from committing future criminal acts, it is styled “specific” or “special” deterrence; if punishment is inflicted to prevent others from committing future criminal acts, it is styled “general” deterrence. In either case, punishment of an action is justified by the future effect of that punishment in deterring future actors from committing crimes. There is some vagueness in the notion of deterrence because of the different mechanisms by which potential criminals are influenced not to be criminals by the example of punishment: such punishment may achieve its effects through fear or by more benignly educating those would-be criminals out of their criminal desires.

Putnam, Hilary b.1926, American philosopher who has made significant contributions to the philosophies of language, science, and mind, and to mathematical logic and metaphysics. He completed his Ph.D. in 1951 at the  of California Los Angeles and has taught at Northwestern, Princeton, MIT, and Harvard. In the late 1950s he contributed with Martin Davis and Julia Robinson to a proof of the unsolvability of Hilbert’s tenth problem completed in 1970 by Yuri Matiyasevich. Rejecting both Platonism and conventionalism in mathematics, he explored the concepts of mathematical truth and logical necessity on the assumption that logic is not entirely immune from empirical revision  e.g., quantum mechanics may require a rejection of classical logic. In the 1950s and 1960s he advanced functionalism, an original theory of mind in which human beings are conceived as Turing machines computers and mental states are functional or    759 computational states. While this theory is presupposed by much contemporary research in cognitive science, Putnam himself in Representation and Reality, 1988 abandoned the view, arguing that genuine intentionality cannot be reduced to computational states because the content of beliefs is a determined by facts external to the individual and b individuatable only by interpreting our belief system as a whole meaning holism. Putnam’s criticism of functionalism relies on the “new theory of reference”  sometimes called the “causal” or “direct” theory  that he and Kripke working independently developed during the late 1960s and early 1970s and that is today embraced by many philosophers and scientists. In “The Meaning of ‘Meaning’ ” 1975 Putnam claims that the reference of natural kind terms like ‘water’ is determined by facts about the world  the microphysical structure of water H2O and the linguistic practices of speakers  and not by the internal mental states of speakers. Early in his career, Putnam championed scientific realism, rejecting conventionalism and arguing that without a realist commitment to theoretical entities e.g., electrons the success of science would be a “miracle.” In 1976 he famously abandoned metaphysical realism in favor of “internal realism,” which gives up commitment to mind-independent objects and relativizes ontology to conceptual schemes. In a series of model-theoretic arguments, Putnam challenged the metaphysical realist assumption that an epistemically ideal theory might be false, claiming that it requires an implausibly “magical” theory of reference. To the same end, he sought to demonstrate tha

t we are not “brains in a vat” and that radical skepticism is incoherent Reason, Truth and History, 1981. More recently, he has emphasized conceptual relativity in his attack on metaphysical realism’s commitment to “one true theory” and, in his Dewey Lectures 1994, has defended direct perceptual realism, showing his allegiance to everyday “realism.” There is growing appreciation of the underlying unity in Putnam’s work that helps correct his reputation for “changing his mind.” He has consistently sought to do justice both to the “real world” of common sense and science and to distinctly human ways of representing that world. In the 1990s his energies were increasingly directed to our “moral image of the world.” Leading a revival of American pragmatism, he has attacked the factvalue dichotomy, articulating a moral view that resists both relativism and authoritarianism. Putnam’s influence now extends beyond philosophers and scientists, to literary theorists, cognitive linguists, and theologians. 

Pyrrho of Elis c.365c.270 B.C., Grecian philosopher, regarded as the founder of Skepticism. Like Socrates, he wrote nothing, but impressed many with provocative ideas and calm demeanor. His equanimity was admired by Epicurus; his attitude of indifference influenced early Stoicism; his attack on knowledge was taken over by the skeptical Academy; and two centuries later, a revival of Skepticism adopted his name. Many of his ideas were anticipated by earlier thinkers, notably Democritus. But in denying the veracity of all sensations and beliefs, Pyrrho carried doubt to new and radical extremes. According to ancient anecdote, which presents him as highly eccentric, he paid so little heed to normal sensibilities that friends often had to rescue him from grave danger; some nonetheless insisted he lived into his nineties. He is also said to have emulated the “naked teachers” as the Hindu Brahmans were called by Grecians whom he met while traveling in the entourage of Alexander the Great. Pyrrho’s chief exponent and publicist was Timon of Phlius c.325c.235 B.C.. His bestpreserved work, the Silloi “Lampoons”, is a parody in Homeric epic verse that mocks the pretensions of numerous philosophers on an imaginary visit to the underworld. According to Timon, Pyrrho was a “negative dogmatist” who affirmed that knowledge is impossible, not because our cognitive apparatus is flawed, but because the world is fundamentally indeterminate: things themselves are “no more” cold than hot, or good than bad. But Timon makes clear that the key to Pyrrho’s Skepticism, and a major source of his impact, was the ethical goal he sought to achieve: by training himself to disregard all perception and values, he hoped to attain mental tranquility. 

Pythagoras 570?495? B.C., the most famous of the pre-Socratic Grecian philosophers. He emigrated from the island of Samos off Asia Minor to Croton southern Italy in 530. There he Pyrrhonian Skepticism Pythagoras 760    760 founded societies based on a strict way of life. They had great political impact in southern Italy and aroused opposition that resulted in the burning of their meeting houses and, ultimately, in the societies’ disappearance in the fourth century B.C. Pythagoras’s fame grew exponentially with the pasage of time. Plato’s immediate successors in the Academy saw true philosophy as an unfolding of the original insight of Pythagoras. By the time of Iamblichus late third century A.D., Pythagoreanism and Platonism had become virtually identified. Spurious writings ascribed both to Pythagoras and to other Pythagoreans arose beginning in the third century B.C. Eventually any thinker who saw the natural world as ordered according to pleasing mathematical relations e.g., Kepler came to be called a Pythagorean. Modern scholarship has shown that Pythagoras was not a scientist, mathematician, or systematic philosopher. He apparently wrote nothing. The early evidence shows that he was famous for introducing the doctrine of metempsychosis, according to which the soul is immortal and is reborn in both human and animal incarnations. Rules were established to purify the soul including the prohibition against eating beans and the emphasis on training of the memory. General reflections on the natural world such as “number is the wisest thing” and “the most beautiful, harmony” were preserved orally. A belief in the mystical power of number is also visible in the veneration for the tetractys tetrad: the numbers 14, which add up to the sacred number 10. The doctrine of the harmony of the spheres  that the heavens move in accord with number and produce music  may go back to Pythagoras. It is often assumed that there must be more to Pythagoras’s thought than this, given his fame in the later tradition. However, Plato refers to him only as the founder of a way of life Republic 600a9. In his account of pre-Socratic philosophy, Aristotle refers not to Pythagoras himself, but to the “so-called Pythagoreans” whom he dates in the fifth century. 

quale: a property of a mental state or event, in particular of a sensation and a perceptual state, which determine “what it is like” to have them. Sometimes ‘phenomenal properties’ and ‘qualitative features’ are used with the same meaning. The felt difference between pains and itches is said to reside in differences in their “qualitative character,” i.e., their qualia. For those who accept an “actobject” conception of perceptual experience, qualia may include such properties as “phenomenal redness” and “phenomenal roundness,” thought of as properties of sense-data, “phenomenal objects,” or portions of the visual field. But those who reject this conception do not thereby reject qualia; a proponent of the adverbial analysis of perceptual experience can hold that an experience of “sensing redly” is so in virtue of, in part, what qualia it has, while denying that there is any sense in which the experience itself is red. Qualia are thought of as non-intentional, i.e., non-representational, features of the states that have them. So in a case of “spectrum inversion,” where one person’s experiences of green are “qualitatively” just like another person’s experiences of red, and vice versa, the visual experiences the two have when viewing a ripe tomato would be alike in their intentional features both would be of a red, round, bulgy surface, but would have different qualia. Critics of physicalist and functionalist accounts of mind have argued from the possibility of spectrum inversion and other kinds of “qualia inversion,” and from such facts as that no physical or functional description will tell one “what it is like” to smell coffee, that such accounts cannot accommodate qualia. Defenders of such accounts are divided between those who claim that their accounts can accommodate qualia and those who claim that qualia are a philosophical myth and thus that there are none to accommodate. 

qualitative predicate, a kind of predicate postulated in some attempts to solve the grue paradox. 1 On the syntactic view, a qualitative predicate is a syntactically more or less simple predicate. Such simplicity, however, is relative to the choice of primitives in a language. In English, ‘green’ and ‘blue’ are primitive, while ‘grue’ and ‘bleen’ must be introduced by definitions ‘green and first examined before T, or blue otherwise’, ‘blue and first examined before T, or green otherwise’, respectively. In other languages, ‘grue’ and ‘bleen’ may be primitive and hence “simple,” while ‘green’ and ‘blue’ must be introduced by definitions ‘grue and first examined before T, or bleen otherwise’, ‘bleen and first examined before T, or grue otherwise’, respectively. 2 On the semantic view, a qualitative predicate is a predicate to which there corresponds a property that is “natural” to us or of easy semantic access. The quality of greenness is easy and natural; the quality of grueness is strained. 3 On the ontological view, a qualitative predicate is a predicate to which there corresponds a property that is woven into the causal or modal structure of reality in a way that gruesome properties are not. 

qualities, properties or characteristics. There are three specific philosophical senses. 1 Qualities are physical properties, logical constructions of physical properties, or dispositions. Physical properties, such as mass, shape, and electrical charge, are properties in virtue of which objects can enter into causal relations. Logical constructions of physical properties include conjunctions and disjunctions of them; being 10 # .02 cm long is a disjunctive property. A disposition of an object is a potential for the object to enter into a causal interaction of some specific kind under some specific condition; e.g., an object is soluble in water if and only if it would dissolve were it in enough pure water. Locke held a very complex theory of powers. On Locke’s theory, the dispositions of objects are a kind of power and the human will is a kind of power. However, the human will is not part of 762 Q    762 the modern notion of disposition. So, predicating a disposition of an object implies a subjunctive conditional of the form: if such-and-such were to happen to the object, then so-and-so would happen to it; that my vase is fragile implies that if my vase were to be hit sufficiently hard then it would break. Whether physical properties are distinct from dispositions is disputed. Three sorts of qualities are often distinguished. Primary qualities are physical properties or logical constructions from physical properties. Secondary qualities are dispositions to produce sensory experiences of certain phenomenal sorts under appropriate conditions. The predication of a secondary quality, Q, to an object implies that if the object were to be perceived under normal conditions then the object would appear to be Q to the perceivers: if redness is a secondary quality, then that your coat is red implies that if your coat were to be seen under normal conditions, it would look red. Locke held that the following are secondary qualities: colors, tastes, smells, sounds, and warmth or cold. Tertiary qualities are dispositions that are not secondary qualities, e.g. fragility. Contrary to Locke, the color realist holds that colors are either primary or tertiary qualities; so that x is yellow is logically independent of the fact that x looks yellow under normal conditions. Since different spectral reflectances appear to be the same shade of yellow, some color realists hold that any shade of yellow is a disjunctive property whose components are spectral reflectances. 2 Assuming a representative theory of perception, as Locke did, qualities have two characteristics: qualities are powers or dispositions of objects to produce sensory experiences sensedata on some theories in humans; and, in sensory experience, qualities are represented as intrinsic properties of objects. Instrinsic properties of objects are properties that objects have independently of their environment. Hence an exact duplicate of an object has all the intrinsic properties of the original, and an intrinsic property of x never has the form, x-stands-in-suchand-such-a-relation-to-y. Locke held that the primary qualities are extension size, figure shape, motion or rest, solidity impenetrability, and number; the primary qualities are correctly represented in perception as intrinsic features of objects, and the secondary qualities listed in 1 are incorrectly represented in perception as intrinsic features of objects. Locke seems to have been mistaken in holding that number is a quality of objects. Positional qualities are qualities defined in terms of the relative positions of points in objects and their surrounding: shape, size, and motion and rest. Since most of Locke’s primary qualities are positional, some non-positional quality is needed to occupy positions. On Locke’s account, solidity fulfills this role, although some have argued Hume that solidity is not a primary quality. 3 Primary qualities are properties common to and inseparable from all matter; secondary qualities are not really qualities in objects, but only powers of objects to produce sensory effects in us by means of their primary qualities. This is another use of ‘quality’ by Locke, where ‘primary’ functions much like ‘real’ and real properties are given by the metaphysical assumptions of the science of Locke’s time. Qualities are distinct from representations of them in predications. Sometimes the same quality is represented in different ways by different predications: ‘That is water’ and ‘That is H2O’. The distinction between qualities and the way they are represented in predications opens up the Lockean possibility that some qualities are incorrectly represented in some predications. Features of predications are sometimes used to define a quality; dispositions are sometimes defined in terms of subjunctive conditionals see definition of ‘secondary qualities’ in 1, and disjunctive properties are defined in terms of disjunctive predications. Features of predications are also used in the following definition of ‘independent qualities’: two qualities, P and Q, are independent if and only if, for any object x, the predication of P and of Q to x are logically independent i.e., that x is P and that x is Q are logically independent; circularity and redness are independent, circularity and triangularity are dependent. If two determinate qualities, e.g., circularity and triangularity, belong to the same determinable, say shape, then they are dependent, but if two determinate qualities, e.g., squareness and redness, belong to different determinables, say shape and color, they are independent.

quantification, the application of one or more quantifiers e.g., ‘for all x’, ‘for some y’ to an open formula. A quantification or quantified sentence results from first forming an open formula from a sentence by replacing expressions belonging to a certain class of expressions in the sentences by variables whose substituends are quality quantification 763    763 the expressions of that class and then prefixing the formula with quantifiers using those variables. For example, from ‘Bill hates Mary’ we form ‘x hates y’, to which we prefix the quantifiers ‘for all x’ and ‘for some y’, getting the quantification sentence ‘for all x, for some y, x hates y’ ‘Everyone hates someone’. In referential quantification only terms of reference may be replaced by variables. The replaceable terms of reference are the substituends of the variables. The values of the variables are all those objects to which reference could be made by a term of reference of the type that the variables may replace. Thus the previous example ‘for all x, for some y, x hates y’ is a referential quantification. Terms standing for people ‘Bill’, ‘Mary’, e.g. are the substituends of the variables ‘x’ and ‘y’. And people are the values of the variables. In substitutional quantification any type of term may be replaced by variables. A variable replacing a term has as its substituends all terms of the type of the replaced term. For example, from ‘Bill married Mary’ we may form ‘Bill R Mary’, to which we prefix the quantifier ‘for some R’, getting the substitutional quantification ‘for some R, Bill R Mary’. This is not a referential quantification, since the substituends of ‘R’ are binary predicates such as ‘marries’, which are not terms of reference. Referential quantification is a species of objectual quantification. The truth conditions of quantification sentences objectually construed are understood in terms of the values of the variable bound by the quantifier. Thus, ‘for all v, fv’ is true provided ‘fv’ is true for all values of the variable ‘v’; ‘for some v, fv’ is true provided ‘fv’ is true for some value of the variable ‘v’. The truth or falsity of a substitutional quantification turns instead on the truth or falsity of the sentences that result from the quantified formula by replacing variables by their substituends. For example, ‘for some R, Bill R Mary’ is true provided some sentence of the form ‘Bill R Mary’ is true. In classical logic the universal quantifier ‘for all’ is definable in terms of negation and the existential quantifier ‘for some’: ‘for all x’ is short for ‘not for some x not’. The existential quantifier is similarly definable in terms of negation and the universal quantifier. In intuitionistic logic, this does not hold. Both quantifiers are regarded as primitive.

quantifying in, use of a quantifier outside of an opaque construction to attempt to bind a variable within it, a procedure whose legitimacy was first questioned by Quine. An opaque construction is one that resists substitutivity of identity. Among others, the constructions of quotation, the verbs of propositional attitude, and the logical modalities can give rise to opacity. For example, the position of ‘six’ in: 1 ‘six’ contains exactly three letters is opaque, since the substitution for ‘six’ by its codesignate ‘immediate successor of five’ renders a truth into a falsehood: 1H ‘the immediate successor of five’ contains exactly three letters. Similarly, the position of ‘the earth’ in: 2 Tom believes that the earth is habitable is opaque, if the substitution of ‘the earth’ by its codesignate ‘the third planet from the sun’ renders a sentence that Tom would affirm into one that he would deny: 2H Tom believes that the third planet from the sun is habitable. Finally, the position of ‘9’ and of ‘7’ in: 3 Necessarily 9  7 is opaque, since the substitution of ‘the number of major planets’ for its codesignate ‘9’ renders a truth into a falsehood: 3H Necessarily the number of major planets  7. Quine argues that since the positions within opaque constructions resist substitutivity of identity, they cannot meaningfully be quantified. Accordingly, the following three quantified sentences are meaningless: 1I Ex ‘x’  7, 2I Ex Tom believes that x is habitable, quantificational shift fallacy quantifying in 764    764 3I Ex necessarily x  7. 1I, 2I, and 3I are meaningless, since the second occurrence of ‘x’ in each of them does not function as a variable in the ordinary nonessentialist quantificational way. The second occurrence of ‘x’ in 1I functions as a name that names the twenty-fourth letter of the alphabet. The second occurrences of ‘x’ in 2I and in 3I do not function as variables, since they do not allow all codesignative terms as substituends without change of truth-value. Thus, they may take objects as values but only objects designated in certain ways, e.g., in terms of their intensional or essential properties. So, short of acquiescing in an intensionalist or essentialist metaphysics, Quine argues, we cannot in general quantify into opaque contexts. 

quantum logic, the logic of which the models are certain non-Boolean algebras derived from the mathematical representation of quantum mechanical systems. The models of classical logic are, formally, Boolean algebras. This is the central notion of quantum logic in the literature, although the term covers a variety of modal logics, dialogics, and operational logics proposed to elucidate the structure of quantum mechanics and its relation to classical mechanics. The dynamical quantities of a classical mechanical system position, momentum, energy, etc. form a commutative algebra, and the dynamical properties of the system e.g., the property that the position lies in a specified range, or the property that the momentum is greater than zero, etc. form a Boolean algebra. The transition from classical to quantum mechanics involves the transition from a commutative algebra of dynamical quantities to a noncommutative algebra of so-called observables. One way of understanding the conceptual revolution from classical to quantum mechanics is in terms of a shift from the class of Boolean algebras to a class of non-Boolean algebras as the appropriate relational structures for the dynamical properties of mechanical systems, hence from a Boolean classical logic to a non-Boolean quantum logic as the logic applicable to the fundamental physical processes of our universe. This conception of quantum logic was developed formally in a classic 1936 paper by G. Birkhoff and J. von Neumann although von Neumann first proposed the idea in 1927. The features that distinguish quantum logic from classical logic vary with the formulation. In the Birkhoffvon Neumann logic, the distributive law of classical logic fails, but this is by no means a feature of all versions of quantum logic. It follows from Gleason’s theorem 1957 that the non-Boolean models do not admit two-valued homomorphisms in the general case, i.e., there is no partition of the dynamical properties of a quantum mechanical system into those possessed by the system and those not possessed by the system that preserves algebraic structure, and equivalently no assignment of values to the observables of the system that preserves algebraic structure. This result was proved independently for finite sets of observables by S. Kochen and E. P. Specker 1967. It follows that the probabilities specified by the Born interpretation of the state function of a quantum mechanical system for the results of measurements of observables cannot be derived from a probability distribution over the different possible sets of dynamical properties of the system, or the different possible sets of values assignable to the observables of which one set is presumed to be actual, determined by hidden variables in addition to the state function, if these sets of properties or values are required to preserve algebraic structure. While Bell’s theorem 1964 excludes hidden variables satisfying a certain locality condition, the Kochen-Specker theorem relates the non-Booleanity of quantum logic to the impossibility of hidden variable extensions of quantum mechanics, in which value assignments to the observables satisfy constraints imposed by the algebraic structure of the observables.

quantum mechanics, also called quantum theory, the science governing objects of atomic and subatomic dimensions. Developed independently by Werner Heisenberg as matrix mechanics, 1925 and Erwin Schrödinger as wave mechanics, 1926, quantum mechanics breaks with classical treatments of the motions and interactions of bodies by introducing probability and acts of measurement in seemingly irreducible ways. In the widely used Schrödinger version, quantum mechanics associates with each physical system a time-dependent function, called the state function alternatively, the state vector or Y function. The evolution of the system is represented quantity quantum mechanics 765    765 quantum mechanics quantum mechanics 766 by the temporal transformation of the state function in accord with a master equation, known as the Schrödinger equation. Also associated with a system are “observables”: in principle measurable quantities, such as position, momentum, and energy, including some with no good classical analogue, such as spin. According to the Born interpretation 1926, the state function is understood instrumentally: it enables one to calculate, for any possible value of an observable, the probability that a measurement of that observable would find that particular value. The formal properties of observables and state functions imply that certain pairs of observables such as linear momentum in a given direction, and position in the same direction are incompatible in the sense that no state function assigns probability 1 to the simultaneous determination of exact values for both observables. This is a qualitative statement of the Heisenberg uncertainty principle alternatively, the indeterminacy principle, or just the uncertainty principle. Quantitatively, that principle places a precise limit on the accuracy with which one may simultaneously measure a pair of incompatible observables. There is no corresponding limit, however, on the accuracy with which a single observable say, position alone, or momentum alone may be measured. The uncertainty principle is sometimes understood in terms of complementarity, a general perspective proposed by Niels Bohr according to which the connection between quantum phenomena and observation forces our classical concepts to split into mutually exclusive packages, both of which are required for a complete understanding but only one of which is applicable under any particular experimental conditions. Some take this to imply an ontology in which quantum objects do not actually possess simultaneous values for incompatible observables; e.g., do not have simultaneous position and momentum. Others would hold, e.g., that measuring the position of an object causes an uncontrollable change in its momentum, in accord with the limits on simultaneous accuracy built into the uncertainty principle. These ways of treating the principle are not uncontroversial. Philosophical interest arises in part from where the quantum theory breaks with classical physics: namely, from the apparent breakdown of determinism or causality that seems to result from the irreducibly statistical nature of the theory, and from the apparent breakdown of observer-independence or realism that seems to result from the fundamental role of measurement in the theory. Both features relate to the interpretation of the state function as providing only a summary of the probabilities for various measurement outcomes. Einstein, in particular, criticized the theory on these grounds, and in 1935 suggested a striking thought experiment to show that, assuming no action-at-a-distance, one would have to consider the state function as an incomplete description of the real physical state for an individual system, and therefore quantum mechanics as merely a provisional theory. Einstein’s example involved a pair of systems that interact briefly and then separate, but in such a way that the outcomes of various measurements performed on each system, separately, show an uncanny correlation. In 1951 the physicist David Bohm simplified Einstein’s example, and later 1957 indicated that it may be realizable experimentally. The physicist John S. Bell then formulated a locality assumption 1964, similar to Einstein’s, that constrains factors which might be used in describing the state of an individual system, so-called hidden variables. Locality requires that in the EinsteinBohm experiment hidden variables not allow the measurement performed on one system in a correlated pair immediately to influence the outcome obtained in measuring the other, spatially separated system. Bell demonstrated that locality in conjunction with other assumptions about hidden variables restricts the probabilities for measurement outcomes according to a system of inequalities known as the Bell inequalities, and that the probabilities of certain quantum systems violate these inequalities. This is Bell’s theorem. Subsequently several experiments of the Einstein-Bohm type have been performed to test the Bell inequalities. Although the results have not been univocal, the consensus is that the experimental data support the quantum theory and violate the inequalities. Current research is trying to evaluate the implications of these results, including the extent to which they rule out local hidden variables. See J. Cushing and E. McMullin, eds., Philosophical Consequences of Quantum Theory, 1989. The descriptive incompleteness with which Einstein charged the theory suggests other problems. A particularly dramatic one arose in correspondence between Schrödinger and Einstein; namely, the “gruesome” Schrödinger cat paradox. Here a cat is confined in a closed chamber containing a radioactive atom with a fifty-fifty chance of decaying in the next hour. If the atom decays it triggers a relay that causes a hammer to fall and smash a glass vial holding a quantity of    766 prussic acid sufficient to kill the cat. According to the Schrödinger equation, after an hour the state function for the entire atom ! relay ! hammer ! glass vial ! cat system is such that if we observe the cat the probability for finding it alive dead is 50 percent. However, this evolved state function is one for which there is no definite result; according to it, the cat is neither alive nor dead. How then does any definite fact of the matter arise, and when? Is the act of observation itself instrumental in bringing about the observed result, does that result come about by virtue of some special random process, or is there some other account compatible with definite results of measurements? This is the so-called quantum measurement problem and it too is an active area of research. 

quasi-indicator, Castañeda’s term for an expression used to ascribe indexical reference to a speaker or thinker. If John says “I am hungry” it is incorrect to report what he said with ‘John claims that I am hungry’, since ‘I’, being an indexical, expresses speaker’s reference, not John’s. However, ‘John claims that John is hungry’ fails to represent the indexical element of his assertion. Instead, we use ‘John claims that he himself is hungry’, where ‘he himself’ is a quasiindicator depicting John’s reference to himself qua self. Because of its subjective and perspectival character, we cannot grasp the exact content of another’s indexical reference, yet quasi-indexical representations are possible since we confront the world through generically the same indexical modes of presentation. If these modes are irreducible, then quasi-indicators are indispensable for describing the thoughts and experiences of others. As such, they are not equivalent to or replaceable by any antecedents occurring outside the scope of psychological verbs to which they are subordinated.  CASTAÑEDA, GUISE THEORY, INDEXICAL, SCOPE. T.K. quasi-quotes.CORNERS. quaternio terminorum.

Quine, Willard Van Orman b.1908, American philosopher and logician, renowned for his rejection of the analyticsynthetic distinction and for his advocacy of extensionalism, naturalism, physicalism, empiricism, and holism. Quine took his doctorate in philosophy at Harvard in 1932. After four years of postdoctoral fellowships, he was appointed to the philosophy faculty at Harvard in 1936. There he remained until he retired from teaching in 1978. During six decades Quine published scores of journal articles and more than twenty books. His writings touch a number of areas, including logic, philosophy of logic, set theory, philosophy of language, philosophy of mind, philosophy of science, metaphysics, epistemology, and ethics. Among his most influential articles and books are “New Foundations for Mathematical Logic” 1936, “Two Dogmas of Empiricism” 1951, “Epistemology Naturalized” 1969, and Word and Object 1960. In “New Foundations” he develops a set theory that avoids Russell’s paradox without relying on Russell’s theory of types. Rather, following Ernst Zermelo, Quine drops the presumption that every membership condition determines a set. The system of “New Foundations” continues to be widely discussed by mathematicians. “Two Dogmas” sets out to repudiate what he sees as two dogmas of logical empiricism. The first is the so-called analyticsynthetic distinction; the second is a weak form of reductionism to the effect that each synthetic statement has associated with it a unique set of confirming experiences and a unique set of infirming experiences. Against the first dogma, Quine argues that none of the then-current attempts to characterize analyticity e.g., “a statement is analytic if and only if it is true solely in virtue of its meaning” do so with sufficient clarity, and that any similar characterization is likewise doomed to fail. Against the second dogma, Quine argues that a more accurate account of the relation between the statements of a theory and experience is holistic rather than reductionistic, that is, only as a corporate body do the statements of a theory face the tribunal of experience. Quine concludes that the effects of rejecting these two dogmas of empiricism are 1 a blurring of the supposed boundary between speculative metaphysics and natural science and 2 a shift toward pragmatism. In “Epistemology Naturalized” Quine argues in favor of naturalizing epistemology: old-time epistemology first philosophy has failed in its attempt to ground science on something firmer than science and should, therefore, be replaced by a scientific account of how we acquire our overall theory of the world and why it works so well. quasi-indicator Quine, Willard Van Orman 767    767 In Word and Object, Quine’s most famous book, he argues in favor of 1 naturalizing epistemology, 2 physicalism as against phenomenalism and mindbody dualism, and 3 extensionality as against intensionality. He also 4 develops a behavioristic conception of sentence-meaning, 5 theorizes about language learning, 6 speculates on the ontogenesis of reference, 7 explains various forms of ambiguity and vagueness, 8 recommends measures for regimenting language so as to eliminate ambiguity and vagueness as well as to make a theory’s logic and ontic commitments perspicuous “to be is to be the value of a bound variable”, 9 argues against quantified modal logic and the essentialism it presupposes, 10 argues for Platonic realism in mathematics, 11 argues for scientific realism and against instrumentalism, 12 develops a view of philosophical analysis as explication, 13 argues against analyticity and for holism, 14 argues against countenancing propositions, and 15 argues that the meanings of theoretical sentences are indeterminate and that the reference of terms is inscrutable. Quine’s subsequent writings have largely been devoted to summing up, clarifying, and expanding on themes found in Word and Object. 

Englishness – Englishry, -- St. George for England. A critique of racism, hostility, contempt, condescension, or prejudice, on the basis of social practices of racial classification, and the wider phenomena of social, economic, and political mistreatment that often accompany such classification. The most salient instances of racism include the Nazi ideology of the “Aryan master race,” American chattel slavery, South African apartheid in the late twentieth century, and the “Jim Crow” laws and traditions of segregation that subjugated African descendants in the Southern United States during the century after the American Civil War. Social theorists dispute whether, in its essence, racism is a belief or an ideology of racial inferiority, a system of social oppression on the basis of race, a form of discourse, discriminatory conduct, or an attitude of contempt or heartlessness and its expression in individual or collective behavior. The case for any of these as the essence of racism has its drawbacks, and a proponent must show how the others can also come to be racist in virtue of that essence. Some deny that racism has any nature or essence, insisting it is nothing more than changing historical realities. However, these thinkers must explain what makes each reality an instance of racism. Theorists differ over who and what can be racist and under what circumstances, some restricting racism to the powerful, others finding it also in some reactions by the oppressed. Here, the former owe an explanation of why power is necessary for racism, what sort economic or political? general or contextual?, and in whom or what racist individuals? their racial groups?. Although virtually everyone thinks racism objectionable, people disagree over whether its central defect is cognitive irrationality, prejudice, economic/prudential inefficiency, or moral unnecessary suffering, unequal treatment. Finally, racism’s connection with the ambiguous and controversial concept of race itself is complex. Plainly, racism presupposes the legitimacy of racial classifications, and perhaps the metaphysical reality of races. Nevertheless, some hold that racism is also prior to race, with racial classifications invented chiefly to explain and help justify the oppression of some peoples by others. The term originated to designate the pseudoscientific theories of racial essence and inferiority that arose in Europe in the nineteenth century and were endorsed by Germany’s Third Reich. Since the civil rights movement in the United States after World War II, the term has come to cover a much broader range of beliefs, attitudes, institutions, and practices. Today one hears charges of unconscious, covert, institutional, paternalistic, benign, anti-racist, liberal, and even reverse racism. Racism is widely regarded as involving ignorance, irrationality, unreasonableness, injustice, and other intellectual and moral vices, to such an extent that today virtually no one is willing to accept the classification of oneself, one’s beliefs, and so on, as racist, except in contexts of self-reproach. As a result, classifying anything as racist, beyond the most egregious cases, is a serious charge and is often hotly disputed.

Ramanuja 1017?1137?, Indian philosopher who founded the Visistadvaita tradition. His theistic system provides the theoretical basis for Bhakti devotional Hinduism. His most important writings are the Sribhafya a commentary on the Brahma-Sutras of Badarayana that presents an interpretation competitive to Shankara’s, the Gita-Bhacya a commentary on the Bhagavad Gita, and the Vedarthasamgraha a commentary on the Upanishads. He rejects natural theology, offers a powerful criticism of Advaita Vedanta, and presents a systematic articulation of devotional theism. 

Ramsey: p. r. – cited by Grice, “The Ramseyfied description. Frank Plumpton 190330, influential 769 R    769 British philosopher of logic and mathematics. His primary interests were in logic and philosophy, but decades after his untimely death two of his publications sparked new branches of economics, and in pure mathematics his combinatorial theorems gave rise to “Ramsey theory” Economic Journal 1927, 1928; Proc. London Math. Soc., 1928. During his lifetime Ramsey’s philosophical reputation outside Cambridge was based largely on his architectural reparation of Whitehead and Russell’s Principia Mathematica, strengthening its claim to reduce mathematics to the new logic formulated in Volume 1  a reduction rounded out by Wittgenstein’s assessment of logical truths as tautologous. Ramsey clarified this logicist picture of mathematics by radically simplifying Russell’s ramified theory of types, eliminating the need for the unarguable axiom of reducibility Proc. London Math. Soc., 1925. His philosophical work was published mostly after his death. The canon, established by Richard Braithwaite The Foundations of Mathematics . . . , 1931, remains generally intact in D. H. Mellor’s edition Philosophical Papers, 1990. Further writings of varying importance appear in his Notes on Philosophy, Probability and Mathematics M. C. Galavotti, ed., 1991 and On Truth Nicholas Rescher and Ulrich Majer, eds., 1991. As an undergraduate Ramsey observed that the redundancy account of truth “enables us to rule out at once some theories of truth such as that ‘to be true’ means ‘to work’ or ‘to cohere’ since clearly ‘p works’ and ‘p coheres’ are not equivalent to ‘p’.” Later, in the canonical “Truth and Probability” 1926, he readdressed to knowledge and belief the main questions ordinarily associated with truth, analyzing probability as a mode of judgment in the framework of a theory of choice under uncertainty. Reinvented and acknowledged by L. J. Savage Foundations of Statistics, 1954, this forms the theoretical basis of the currently dominant “Bayesian” view of rational decision making. Ramsey cut his philosophical teeth on Wittgenstein’s Tractatus LogicoPhilosophicus. His translation appeared in 1922; a long critical notice of the work 1923 was his first substantial philosophical publication. His later role in Wittgenstein’s rejection of the Tractatus is acknowledged in the foreword to Philosophical Investigations 1953. The posthumous canon has been a gold mine. An example: “Propositions” 1929, reading the theoretical terms T, U, etc. of an axiomatized scientific theory as variables, sees the theory’s content as conveyed by a “Ramsey sentence” saying that for some T, U, etc., the theory’s axioms are true, a sentence in which all extralogical terms are observational. Another example: “General Propositions and Causality” 1929, offering in a footnote the “Ramsey test” for acceptability of conditionals, i.e., add the if-clause to your ambient beliefs minimally modified to make the enlarged set self-consistent, and accept the conditional if the then-clause follows. 

Ramus, Petrus, in French, Pierre de La Ramée 151572, French philosopher who questioned the authority of Aristotle and influenced the methods and teaching of logic through the seventeenth century. In 1543 he published his Dialecticae institutiones libri XV, and in 1555 reworked it as Dialectique  the first philosophical work in French. He was appointed by François I as the first Regius Professor of the  of Paris, where he taught until he was killed in the St. Bartholomew’s Day Massacre in 1572. Ramus doubted that we can apodictically intuit the major premises required for Aristotle’s rational syllogism. Turning instead to Plato, Ramus proposed that a “Socratizing” of logic would produce a more workable and fruitful result. As had Agricola and Sturm, he reworked the rhetorical and liberal arts traditions’ concepts of “invention, judgment, and practice,” placing “method” in the center of judgment. Proceeding in these stages, we can “read” nature’s “arguments,” because they are modeled on natural reasoning, which in turn can emulate the reasoning by which God creates. Often his results were depicted graphically in tables as in chapter IX of Hobbes’s Leviathan. When carefully done they would show both what is known and where gaps require further investigation; the process from invention to judgment is continuous. Ramus’s works saw some 750 editions in one century, fostering the “Ramist” movement in emerging Protestant universities and the American colonies. He influenced Bacon, Hobbes, Milton, Methodism, Cambridge Platonism, and Alsted in Europe, and Hooker and Congregationalism in Puritan America. Inconsistencies make him less than a major figure in the history Ramsey-eliminability Ramus, Petrus 770    770 of logic, but his many works and their rapid popularity led to philosophical and educational efforts to bring the world of learning to the “plain man” by using the vernacular, and by more closely correlating the rigor of philosophy with the memorable and persuasive powers of rhetoric; he saw this goal as Socratic.

Rashdall, Hastings 18581924, English historian, theologian, and personal idealist. While acknowledging that Berkeley needed to be corrected by Kant, Rashdall defended Berkeley’s thesis that objects only exist for minds. From this he concluded that there is a divine mind that guarantees the existence of nature and the objectivity of morality. In his most important philosophical work, The Theory of Good and Evil 1907, Rashdall argued that actions are right or wrong according to whether they produce well-being, in which pleasure as well as a virtuous disposition are constituents. Rashdall coined the name ‘ideal utilitarianism’ for this view.

rationalism, the position that reason has precedence over other ways of acquiring knowledge, or, more strongly, that it is the unique path to knowledge. It is most often encountered as a view in epistemology, where it is traditionally contrasted with empiricism, the view that the senses are primary with respect to knowledge. It is important here to distinguish empiricism with respect to knowledge from empiricism with respect to ideas or concepts; whereas the former is opposed to rationalism, the latter is opposed to the doctrine of innate ideas. The term is also encountered in the philosophy of religion, where it may designate those who oppose the view that revelation is central to religious knowledge; and in ethics, where it may designate those who oppose the view that ethical principles are grounded in or derive from emotion, empathy, or some other non-rational foundation. The term ‘rationalism’ does not generally designate a single precise philosophical position; there are several ways in which reason can have precedence, and several accounts of knowledge to which it may be opposed. Furthermore, the very term ‘reason’ is not altogether clear. Often it designates a faculty of the soul, distinct from sensation, imagination, and memory, which is the ground of a priori knowledge. But there are other conceptions of reason, such as the narrower conception in which Pascal opposes reason to “knowledge of the heart” Pensées, section 110, or the computational conception of reason Hobbes advances in Leviathan I.5. The term might thus be applied to a number of philosophical positions from the ancients down to the present. Among the ancients, ‘rationalism’ and ‘empiricism’ especially denote two schools of medicine, the former relying primarily on a theoretical knowledge of the hidden workings of the human body, the latter relying on direct clinical experience. The term might also be used to characterize the views of Plato and later Neoplatonists, who argued that we have pure intellectual access to the Forms and general principles that govern reality, and rejected sensory knowledge of the imperfect realization of those Forms in the material world. In recent philosophical writing, the term ‘rationalism’ is most closely associated with the positions of a group of seventeenth-century philosophers, Descartes, Spinoza, Leibniz, and sometimes Malebranche. These thinkers are often referred to collectively as the Continental rationalists, and are generally opposed to the socalled British empiricists, Locke, Berkeley, and Hume. All of the former share the view that we have a non-empirical and rational access to the truth about the way the world is, and all privilege reason over knowledge derived from the senses. These philosophers are also attracted to mathematics as a model for knowledge in general. But these common views are developed in quite different ways. Descartes claims to take his inspiration from mathematics  not mathematics as commonly understood, but the analysis of the ancients. According to Descartes, we start from first principles known directly by reason the cogito ergo sum of the Meditations, what he calls intuition in his Rules for the Direction of the Mind; all other knowledge is deduced from there. A central aim of his Meditations is to show that this faculty of reason is trustworthy. The senses, on the other hand, are generally deceptive, leading us to mistake sensory qualities for real qualities of extended bodies, and leading us to the false philosophy of Aristotle and to Scholasticism. Descartes does not reject the senses altogether; in Meditation VI he argues that the senses are most often correct in circumstances concerning the preservation of life. Perhaps paradoxically, experiment is important to Descartes’s scientific randomness rationalism 771    771 work. However, his primary interest is in the theoretical account of the phenomena experiment reveals, and while his position is unclear, he may have considered experiment as an auxiliary to intuition and deduction, or as a second-best method that can be used with problems too complex for pure reason. Malebranche, following Descartes, takes similar views in his Search after Truth, though unlike Descartes, he emphasizes original sin as the cause of our tendency to trust the senses. Spinoza’s model for knowledge is Euclidean geometry, as realized in the geometrical form of the Ethics. Spinoza explicitly argues that we cannot have adequate ideas of the world through sensation Ethics II, propositions 1631. In the Ethics he does see a role for the senses in what he calls knowledge of the first and knowledge of the second kinds, and in the earlier Emendation of the Intellect, he suggests that the senses may be auxiliary aids to genuine knowledge. But the senses are imperfect and far less valuable, according to Spinoza, than intuition, i.e., knowledge of the third kind, from which sensory experience is excluded. Spinoza’s rationalism is implicit in a central proposition of the Ethics, in accordance with which “the order and connection of ideas is the same as the order and connection of things” Ethics II, proposition 7, allowing one to infer causal connections between bodies and states of the material world directly from the logical connections between ideas. Leibniz, too, emphasizes reason over the senses in a number of ways. In his youth he believed that it would be possible to calculate the truth-value of every sentence by constructing a logical language whose structure mirrors the structure of relations between concepts in the world. This view is reflected in his mature thought in the doctrine that in every truth, the concept of the predicate is contained in the concept of the subject, so that if one could take the God’s-eye view which, he concedes, we cannot, one could determine the truth or falsity of any proposition without appeal to experience Discourse on Metaphysics, section 8. Leibniz also argues that all truths are based on two basic principles, the law of non-contradiction for necessary truths, and the principle of sufficient reason for contingent truths Monadology, section 31, both of which can be known a priori. And so, at least in principle, the truth-values of all propositions can be determined a priori. This reflects his practice in physics, where he derives a number of laws of motion from the principle of the equality of cause and effect, which can be known a priori on the basis of the principle of sufficient reason. But, at the same time, referring to the empirical school of ancient medicine, Leibniz concedes that “we are all mere Empirics in three fourths of our actions” Monadology, section 28. Each of the so-called Continental rationalists does, in his own way, privilege reason over the senses. But the common designation ‘Continental rationalism’ arose only much later, probably in the nineteenth century. For their contemporaries, more impressed with their differences than their common doctrines, the Continental rationalists did not form a single homogeneous school of thought. 

rationality. In its primary sense, rationality is a normative concept that philosophers have generally tried to characterize in such a way that, for any action, belief, or desire, if it is rational we ought to choose it. No such positive characterization has achieved anything close to universal assent because, often, several competing actions, beliefs, or desires count as rational. Equating what is rational with what is rationally required eliminates the category of what is rationally allowed. Irrationality seems to be the more fundamental normative category; for although there are conflicting substantive accounts of irrationality, all agree that to say of an action, belief, or desire that it is irrational is to claim that it should always be avoided. Rationality is also a descriptive concept that refers to those intellectual capacities, usually involving the ability to use language, that distinguish persons from plants and most other animals. There is some dispute about whether some non-human animals, e.g., dolphins and chimpanzees, are rational in this sense. Theoretical rationality applies to beliefs. An irrational belief is one that obviously conflicts with what one should know. This characterization of an irrational belief is identical with the psychiatric characterization of a delusion. It is a personrelative concept, because what obviously conflicts with what should be known by one person need not obviously conflict with what should be known by another. On this account, any belief that is not irrational counts as rational. Many positive characterizations of rational beliefs have rationalism, Continental rationality 772    772 been proposed, e.g., 1 beliefs that are either self-evident or derived from self-evident beliefs by a reliable procedure and 2 beliefs that are consistent with the overwhelming majority of one’s beliefs; but all of these positive characterizations have encountered serious objections. Practical rationality applies to actions. For some philosophers it is identical to instrumental rationality. On this view, commonly called instrumentalism, acting rationally simply means acting in a way that is maximally efficient in achieving one’s goals. However, most philosophers realize that achieving one goal may conflict with achieving another, and therefore require that a rational action be one that best achieves one’s goals only when these goals are considered as forming a system. Others have added that all of these goals must be ones that would be chosen given complete knowledge and understanding of what it would be like to achieve these goals. On the latter account of rational action, the system of goals is chosen by all persons for themselves, and apart from consistency there is no external standpoint from which to evaluate rationally any such system. Thus, for a person with a certain system of goals it will be irrational to act morally. Another account of rational action is not at all person-relative. On this account, to act rationally is to act on universalizable principles, so that what is a reason for one person must be a reason for everyone. One point of such an account is to make it rationally required to act morally, thus making all immoral action irrational. However, if to call an action irrational is to claim that everyone would hold that it is always to be avoided, then it is neither irrational to act immorally in order to benefit oneself or one’s friends, nor irrational to act morally even when that goes against one’s system of goals. Only a negative characterization of what is rational as what is not irrational, which makes it rationally permissible to act either morally or in accordance with one’s own system of goals, as long as these goals meet some minimal objective standard, seems likely to be adequate. 

rationalization, 1 an apparent explanation of a person’s action or attitude by appeal to reasons that would justify or exculpate the person for it  if, contrary to fact, those reasons were to explain it; 2 an explanation or interpretation made from a rational perspective. In sense 1, rationalizations are pseudo-explanations, often motivated by a desire to exhibit an item in a favorable light. Such rationalizations sometimes involve self-deception. Depending on one’s view of justification, a rationalization might justify an action  by adducing excellent reasons for its performance  even if the agent, not having acted for those reasons, deserves no credit for so acting. In sense 2 a sense popularized in philosophy by Donald Davidson, rationalizations of intentional actions are genuine explanations in terms of agents’ reasons. In this sense, we provide a rationalization for  or “rationalize”  Robert’s shopping at Zed’s by identifying the reasons for which he does so: e.g., he wants to buy an excellent kitchen knife and believes that Zed’s sells the best cutlery in town. Also, the reasons for which an agent acts may themselves be said to rationalize the action. Beliefs, desires, and intentions may be similarly rationalized. In each case, a rationalization exhibits the rationalized item as, to some degree, rational from the standpoint of the person to whom it is attributed.

rational psychology, the a priori study of the mind. This was a large component of eighteenthand nineteenth-century psychology, and was contrasted by its exponents with empirical psychology, which is rooted in contingent experience. The term ‘rational psychology’ may also designate a mind, or form of mind, having the property of rationality. Current philosophy of mind includes much discussion of rational psychologies, but the notion is apparently ambiguous. On one hand, there is rationality as intelligibility. This is a minimal coherence, say of desires or inferences, that a mind must possess to be a mind. For instance, Donald Davidson, many functionalists, and some decision theorists believe there are principles of rationality of this sort that constrain the appropriate attribution of beliefs and desires to a person, so that a mind must meet such constraints if it is to have beliefs and desires. On another pole, there is rationality as justification. For someone’s psychology to have this property is for that psychology to be as rationality, epistemic rational psychology 773    773 reason requires it to be, say for that person’s inferences and desires to be supported by proper reasons given their proper weight, and hence to be justified. Rationality as justification is a normative property, which it would seem some minds lack. But despite the apparent differences between these two sorts of rationality, some important work in philosophy of mind implies either that these two senses in fact collapse, or at least that there are intervening and significant senses, so that things at least a lot like normative principles constrain what our psychologies are. 

rational reconstruction, also called logical reconstruction, translation of a discourse of a certain conceptual type into a discourse of another conceptual type with the aim of making it possible to say everything or everything important that is expressible in the former more clearly or perspicuously in the latter. The best-known example is one in Carnap’s Der Logische Aufbau der Welt. Carnap attempted to translate discourse concerning physical objects e.g., ‘There is a round brown table’ into discourse concerning immediate objects of sense experience ‘Color patches of such-and-such chromatic characteristics and shape appear in such-and-such a way’. He was motivated by the empiricist doctrine that immediate sense experience is conceptually prior to everything else, including our notion of a physical object. In addition to talk of immediate sense experience, Carnap relied on logic and set theory. Since their use is difficult to reconcile with strict empiricism, his translation would not have fully vindicated empiricism even if it had succeeded. 

Rawls, John b.1921, American philosopher widely recognized as one of the leading political philosophers of the twentieth century. His A Theory of Justice 1971 is one of the primary texts in political philosophy. Political Liberalism 1993 revises Rawls’s theory to make his conception of justice compatible with liberal pluralism, but leaves the core of his conception intact. Drawing on the liberal and democratic social contract traditions of Locke, Rousseau, and Kant, Rawls argues that the most reasonable principles of justice are those everyone would accept and agree to from a fair position. Since these principles determine the justice of society’s political constitution, economy, and property rules its “basic structure”, Rawls takes a fair agreement situation to be one where everyone is impartially situated as equals. In this so-called original position everyone is equally situated by a hypothetical “veil of ignorance.” This veil requires individuals to set aside their knowledge of their particular differences, including knowledge of their talents, wealth, social position, religious and philosophical views, and particular conceptions of value. Rawls argues that in the hypothetical original position everyone would reject utilitarianism, perfectionism, and intuitionist views. Instead they would unanimously accept justice as fairness. This conception of justice consists mainly of two principles. The first principle says that certain liberties are basic and are to be equally provided to all: liberty of conscience, freedom of thought, freedom of association, equal political liberties, freedom and integrity of the person, and the liberties that maintain the rule of law. These are basic liberties, because they are necessary to exercise one’s “moral powers.” The two moral powers are, first, the capacity to be rational, to have a rational conception of one’s good; and second, the capacity for a sense of justice, to understand, apply, and act from requirements of justice. These powers constitute essential interests of free and equal moral persons since they enable each person to be a free and responsible agent taking part in social cooperation. Rawls’s second principle of justice, the difference principle, regulates permissible differences in rights, powers, and privileges. It defines the limits of inequalities in wealth, income, powers, and positions that may exist in a just society. It says, first, that social positions are to be open to all to compete for on terms of fair equality of opportunity. Second, inequalities in wealth, income, and social powers and positions are permissible only if they maximally benefit the least advantaged class in society. The difference principle implies that a just economic system distributes income and wealth so as to make the class of least advantaged persons better off than they would be under any alternative economic system. This principle is to be consistent with the “priority” of the first principle, which requires that equal basic liberties cannot be traded for other benefits. The least advanrational reconstruction Rawls, John 774    774 Ray, John reality 775 taged’s right to vote, for example, cannot be limited for the sake of improving their relative economic position. Instead, a basic liberty can be limited only for the sake of maintaining other basic liberties. Rawls contends that, taking the two principles of justice together, a just society maximizes the worth to the least advantaged of the basic liberties shared by all Theory, p. 205. The priority of basic liberty implies a liberal egalitarian society in which each person is ensured adequate resources to effectively exercise her basic liberties and become independent and self-governing. A just society is then governed by a liberal-democratic constitution that protects the basic liberties and provides citizens with equally effective rights to participate in electoral processes and influence legislation. Economically a just society incorporates a modified market system that extensively distributes income and wealth  either a “property-owning democracy” with widespread ownership of means of production, or liberal socialism. 

Ray, John 16271705, English naturalist whose work on the structure and habits of plants and animals led to important conclusions on the methodology of classification and gave a strong impetus to the design argument in natural theology. In an early paper he argued that the determining characteristics of a species are those transmitted by seed, since color, scent, size, etc., vary with climate and nutriment. Parallels from the animal kingdom suggested the correct basis for classification would be structural. But we have no knowledge of real essences. Our experience of nature is of a continuum, and for practical purposes kinships are best identified by a plurality of criteria. His mature theory is set out in Dissertatio Brevis 1696 and Methodus Emendata 1703. The Wisdom of God Manifested in the Works of the Creation 1691 and three revisions was a best-selling compendium of Ray’s own scientific learning and was imitated and quarried by many later exponents of the design argument. Philosophically, he relied on others, from Cicero to Cudworth, and was superseded by Paley.

reality, in standard philosophical usage, how things actually are, in contrast with their mere appearance. Appearance has to do with how things seem to a particular perceiver or group of perceivers. Reality is sometimes said to be twoway-independent of appearance. This means that appearance does not determine reality. First, no matter how much agreement there is, based on appearance, about the nature of reality, it is always conceivable that reality differs from appearance. Secondly, appearances are in no way required for reality: reality can outstrip the range of all investigations that we are in a position to make. It may be that reality always brings with it the possibility of appearances, in the counterfactual sense that if there were observers suitably situated, then if conditions were not conducive to error, they would have experiences of such-and-such a kind. But the truth of such a counterfactual seems to be grounded in the facts of reality. Phenomenalism holds, to the contrary, that the facts of reality can be explained by such counterfactuals, but phe   775 reality principle reasons for action 776 nomenalists have failed to produce adequate non-circular analyses. The concept of reality on which it is two-wayindependent of experience is sometimes called objective reality. However, Descartes used this phrase differently, to effect a contrast with formal or actual reality. He held that there must be at least as much reality in the efficient and total cause of an effect as in the effect itself, and applied this principle as follows: “There must be at least as much actual or formal reality in the efficient and total cause of an idea as objective reality in the idea itself.” The objective reality of an idea seems to have to do with its having representational content, while actual or formal reality has to do with existence independent of the mind. Thus the quoted principle relates features of the cause of an idea to the representational content of the idea. Descartes’s main intended applications were to God and material objects. 

reasons for action, considerations that call for or justify action. They may be subjective or objective. A subjective reason is a consideration an agent understands to support a course of action, whether or not it actually does. An objective reason is one that does support a course of action, regardless of whether the agent realizes it. What are cited as reasons may be matters either of fact or of value, but when facts are cited values are also relevant. Thus the fact that cigarette smoke contains nicotine is a reason for not smoking only because nicotine has undesirable effects. The most important evaluative reasons are normative reasons  i.e., considerations having e.g. ethical force. Facts become obligating reasons when, in conjunction with normative considerations, they give rise to an obligation. Thus in view of the obligation to help the needy, the fact that others are hungry is an obligating reason to see they are fed. Reasons for action enter practical thinking as the contents of beliefs, desires, and other mental states. But not all the reasons one has need motivate the corresponding behavior. Thus I may recognize an obligation to pay taxes, yet do so only for fear of punishment. If so, then only my fear is an explaining reason for my action. An overriding reason is one that takes precedence over all others. It is often claimed that moral reasons override all others objectively, and should do so subjectively as well. Finally, one may speak of an all-things-considered reason  one that after due consideration is taken as finally determinative of what shall be done.   

reasons for belief, roughly, bases of belief. The word ‘belief’ is commonly used to designate both a particular sort of psychological state, a state of believing, and a particular intentional content or proposition believed. Reasons for belief exhibit an analogous duality. A proposition, p, might be said to provide a normative reason to believe a proposition, q, for instance, when p bears some appropriate warranting relation to q. And p might afford a perfectly good reason to believe q, even though no one, as a matter of fact, believes either p or q. In contrast, p is a reason that I have for believing q, if I believe p and p counts as a reason in the sense above to believe q. Undoubtedly, I have reason to believe countless propositions that I shall never, as it happens, come to believe. Suppose, however, that p is a reason for which I believe q. In that case, I must believe both p and q, and p must be a reason to believe q  or, at any rate, I must regard it as such. It may be that I must, in addition, believe q at least in part because I believe p. Reasons in these senses are inevitably epistemic; they turn on considerations of evidence, truth-conduciveness, and the like. But not all reasons for belief are of this sort. An explanatory reason, a reason why I believe p, may simply be an explanation for my having or coming to have this belief. Perhaps I believe p because I was brainwashed, or struck on the head, or because I have strong non-epistemic motives for this belief. I might, of course, hold the belief on the basis of unexceptionable epistemic grounds. When this is so, my believing p may both warrant and explain my believing q. Reflections of this sort can lead to questions concerning the overall or “all-things-considered” reasonableness of a given belief. Some philosophers e.g., Clifford argue that a belief’s reasonableness depends exclusively on its epistemic standing: my believing p is reasonable for me provided it is epistemically reasonable for me; where belief is concerned, epistemic reasons are overriding. Others, siding with James, have focused on the role of belief in our psychological economy, arguing that the reasonableness of my holding a given belief can be affected by a variety of non-epistemic considerations. Suppose I have some evidence that p is false, but that I stand to benefit in a significant way from coming to believe p. If that is so, and if the practical advantages of my holding p considerably outweigh the practical disadvantages, it might seem obvious that my holding p is reasonable for me in some all-embracing sense. 

recursive function theory, a relatively recent area of mathematics that takes as its point of departure the study of an extremely limited class of arithmetic functions called the recursive functions. Strictly speaking, recursive function theory is a branch of higher arithmetic number theory, or the theory of natural numbers whose universe of discourse is restricted to the nonnegative integers: 0, 1, 2, etc. However, the techniques and results of the newer area do not resemble those traditionally associated with number theory. The class of recursive functions is defined in a way that makes evident that every recursive function can be computed or calculated. The hypothesis that every calculable function is recursive, which is known as Church’s thesis, is often taken as a kind of axiom in recursive function theory. This theory has played an important role in modern philosophy of mathematics, especially when epistemological issues are studied. 

redintegration, a psychological process, similar to reasons for belief redintegration 777    777 or involving classical conditioning, in which one feature of a situation causes a person to recall, visualize, or recompose an entire original situation. On opening a pack of cigarettes, a person may visualize the entire process, including striking the match, lighting the cigarette, and puffing. Redintegration is used as a technique in behavior therapy, e.g. when someone trying to refrain from smoking is exposed to unpleasant odors and vivid pictures of lungs caked with cancer, and then permitted to smoke. If the unpleasantness of the odors and visualization outweighs the reinforcement of smoking, the person may resist smoking. Philosophically, redintegration is of interest for two reasons. First, the process may be critical in prudence. By bringing long-range consequences of behavior into focus in present deliberation, redintegration may help to protect long-range interests. Second, redintegration offers a role for visual images in producing behavior. Images figure in paradigmatic cases of redintegration. In recollecting pictures of cancerous lungs, the person may refrain from smoking. 

reductio ad absurdum. 1 The principles A / - A / -A and -A / A / A. 2 The argument forms ‘If A then B and not-B; therefore, not-A’ and ‘If not-A then B and not-B; therefore, A’ and arguments of these forms. Reasoning via such arguments is known as the method of indirect proof. 3 The rules of inference that permit i inferring not-A having derived a contradiction from A and ii inferring A having derived a contradiction from not-A. Both rules hold in classical logic and come to the same thing in any logic with the law of double negation. In intuitionist logic, however, i holds but ii does not. 

reduction, the replacement of one expression by a second expression that differs from the first in prima facie reference. So-called reductions have been meant in the sense of uniformly applicable explicit definitions, contextual definitions, or replacements suitable only in a limited range of contexts. Thus, authors have spoken of reductive conceptual analyses, especially in the early days of analytic philosophy. In particular, in the sensedatum theory talk of physical objects was supposed to be reduced to talk of sense-data by explicit definitions or other forms of conceptual analysis. Logical positivists talked of the reduction of theoretical vocabulary to an observational vocabulary, first by explicit definitions, and later by other devices, such as Carnap’s reduction sentences. These appealed to a test condition predicate, T e.g., ‘is placed in water’, and a display predicate, D e.g., ‘dissolves’, to introduce a dispositional or other “non-observational” term, S e.g., ‘is water-soluble’: Ex [Tx / Dx / Sx], with ‘/’ representing the material conditional. Negative reduction sentences for non-occurrence of S took the form Ex [NTx / NDx / - Sx]. For coinciding predicate pairs T and TD and -D and ND Carnap referred to bilateral reduction sentences: Ex [Tx / Dx S Sx]. Like so many other attempted reductions, reduction sentences did not achieve replacement of the “reduced” term, S, since they do not fix application of S when the test condition, T, fails to apply. In the philosophy of mathematics, logicism claimed that all of mathematics could be reduced to logic, i.e., all mathematical terms could be defined with the vocabulary of logic and all theorems of mathematics could be derived from the laws of logic supplemented by these definitions. Russell’s Principia Mathematica carried out much of such a program with a reductive base of something much more like what we now call set theory rather than logic, strictly conceived. Many now accept the reducibility of mathematics to set theory, but only in a sense in which reductions are not unique. For example, the natural numbers can equally well be modeled as classes of equinumerous sets or as von Neumann ordinals. This non-uniqueness creates serious difficulties, with suggestions that set-theoretic reductions can throw light on what numbers and other mathematical objects “really are.” In contrast, we take scientific theories to tell us, unequivocally, that water is H20 and that temperature is mean translational kinetic energy. Accounts of theory reduction in science attempt to analyze the circumstance in which a “reducing theory” appears to tell us the composition of objects or properties described by a “reduced theory.” The simplest accounts follow the general pattern of reduction: one provides “identity statements” or “bridge laws,” with at least the form of explicit definitions, for all terms in the reducibility, axiom of reduction 778    778 reduced theory not already appearing in the reducing theory; and then one argues that the reduced theory can be deduced from the reducing theory augmented by the definitions. For example, the laws of thermodynamics are said to be deducible from those of statistical mechanics, together with statements such as ‘temperature is mean translational kinetic energy’ and ‘pressure is mean momentum transfer’. How should the identity statements or bridge laws be understood? It takes empirical investigation to confirm statements such as that temperature is mean translational kinetic energy. Consequently, some have argued, such statements at best constitute contingent correlations rather than strict identities. On the other hand, if the relevant terms and their extensions are not mediated by analytic definitions, the identity statements may be analogized to identities involving two names, such as ‘Cicero is Tully’, where it takes empirical investigation to establish that the two names happen to have the same referent. One can generalize the idea of theory reduction in a variety of ways. One may require the bridge laws to suffice for the deduction of the reduced from the reducing theory without requiring that the bridge laws take the form of explicit identity statements or biconditional correlations. Some authors have also focused on the fact that in practice a reducing theory T2 corrects or refines the reduced theory T1, so that it is really only a correction or refinement, T1*, that is deducible from T2 and the bridge laws. Some have consequently applied the term ‘reduction’ to any pair of theories where the second corrects and extends the first in ways that explain both why the first theory was as accurate as it was and why it made the errors that it did. In this extended sense, relativity is said to reduce Newtonian mechanics. Do the social sciences, especially psychology, in principle reduce to physics? This prospect would support the so-called identity theory of mind and body, in particular resolving important problems in the philosophy of mind, such as the mindbody problem and the problem of other minds. Many though by no means all are now skeptical about the prospects for identifying mental properties, and the properties of other special sciences, with complex physical properties. To illustrate with an example from economics adapted from Fodor, in the right circumstances just about any physical object could count as a piece of money. Thus prospects seem dim for finding a closed and finite statement of the form ‘being a piece of money is . . .’, with only predicates from physics appearing on the right though some would want to admit infinite definitions in providing reductions. Similarly, one suspects that attributes, such as pain, are at best functional properties with indefinitely many possible physical realizations. Believing that reductions by finitely stable definitions are thus out of reach, many authors have tried to express the view that mental properties are still somehow physical by saying that they nonetheless supervene on the physical properties of the organisms that have them. In fact, these same difficulties that affect mental properties affect the paradigm case of temperature, and probably all putative examples of theoretical reduction. Temperature is mean translational temperature only in gases, and only idealized ones at that. In other substances, quite different physical mechanisms realize temperature. Temperature is more accurately described as a functional property, having to do with the mechanism of heat transfer between bodies, where, in principle, the required mechanism could be physically realized in indefinitely many ways. In most and quite possibly all cases of putative theory reduction by strict identities, we have instead a relation of physical realization, constitution, or instantiation, nicely illustrated by the property of being a calculator example taken from Cummins. The property of being a calculator can be physically realized by an abacus, by devices with gears and levers, by ones with vacuum tubes or silicon chips, and, in the right circumstances, by indefinitely many other physical arrangements. Perhaps many who have used ‘reduction’, particularly in the sciences, have intended the term in this sense of physical realization rather than one of strict identity. Let us restrict attention to properties that reduce in the sense of having a physical realization, as in the cases of being a calculator, having a certain temperature, and being a piece of money. Whether or not an object counts as having properties such as these will depend, not only on the physical properties of that object, but on various circumstances of the context. Intensions of relevant language users constitute a plausible candidate for relevant circumstances. In at least many cases, dependence on context arises because the property constitutes a functional property, where the relevant functional system calculational practices, heat transfer, monetary reduction reduction 779    779 systems are much larger than the propertybearing object in question. These examples raise the question of whether many and perhaps all mental properties depend ineliminably on relations to things outside the organisms that have the mental properties. 

reduction sentence, for a given predicate Q3 of space-time points in a first-order language, any universal sentence S1 of the form: x [Q1x / Q2x / Q3 x], provided that the predicates Q1 and Q2 are consistently applicable to the same space-time points. If S1 has the form given above and S2 is of the form x [Q4x / Q5 / - Q6] and either S1 is a reduction sentence for Q3 or S2 is a reduction sentence for -Q3, the pair {S1, S2} is a reduction pair for Q3. If Q1 % Q4 and Q2 % - Q5, the conjunction of S1 and S2 is equivalent to a bilateral reduction sentence for Q3 of the form x [Q1 / Q3 S Q2]. These concepts were introduced by Carnap in “Testability and Meaning,” Philosophy of Science 193637, to modify the verifiability criterion of meaning to a confirmability condition where terms can be introduced into meaningful scientific discourse by chains of reduction pairs rather than by definitions. The incentive for this modification seems to have been to accommodate the use of disposition predicates in scientific discourse. Carnap proposed explicating a disposition predicate Q3 by bilateral reduction sentences for Q3. An important but controversial feature of Carnap’s approach is that it avoids appeal to nonextensional conditionals in explicating disposition predicates. 

referentially transparent. An occurrence of a singular term t in a sentence ‘. . . t . . .’ is referentially transparent or purely referential if and only if the truth-value of ‘. . . t . . .’ depends on whether the referent of t satisfies the open sentence ‘. . . x . . .’; the satisfaction of ‘. . . x . . .’ by the referent of t would guarantee the truth of ‘. . . t . . .’, and failure of this individual to satisfy ‘. . . x . . .’ would guarantee that ‘. . . t . . .’ was not true. ‘Boston is a city’ is true if and only if the referent of ‘Boston’ satisfies the open sentence ‘x is a city’, so the occurrence of ‘Boston’ is referentially transparent. But in ‘The expression “Boston” has six letters’, the length of the word within the quotes, not the features of the city Boston, determines the truth-value of the sentence, so the occurrence is not referentially transparent. According to a Fregean theory of meaning, the reference of any complex expression that is a meaningful unit is a function of the referents of its parts. Within this context, an occurrence of a referential term t in a meaningful expression ‘. . . t . . .’ is referentially transparent or purely referential if and only if t contributes its referent to the reference of ‘. . . t . . .’. The expression ‘the area around Boston’ refers to the particular area it does because of the referent of ‘Boston’ and the reference or extension of the function expressed by ‘the area around x’. An occurrence of a referential term t in a meaningful expression ‘. . . t . . .’ is referentially opaque if and only if it is not referentially transparent. Thus, if t has a referentially opaque occurrence in a sentence ‘. . . t . . .’, then the truth-value of ‘. . . t . . .’ depends on something reduction, phenomenological referentially transparent 780    780 other than whether the referent of t satisfies ‘. . . x . . .’. Although these definitions apply to occurrences of referential terms, the terms ‘referentially opaque’ and ‘referentially transparent’ are used primarily to classify linguistic contexts for terms as referentially opaque contexts. If t occurs purely referentially in S but not in CS, then C   is a referentially opaque context. But we must qualify this: C  is a referentially opaque context for that occurrence of t in S. It would not follow without further argument that C  is a referentially opaque context for other occurrences of terms in sentences that could be placed into C . Contexts of quotation, propositional attitude, and modality have been widely noted for their potential to produce referential opacity. Consider: 1 John believes that the number of planets is less than eight. 2 John believes that nine is less than eight. If 1 is true but 2 is not, then either ‘the number of planets’ or ‘nine’ has an occurrence that is not purely referential, because the sentences would differ in truth-value even though the expressions are co-referential. But within the sentences: 3 The number of planets is less than eight. 4 Nine is less than eight. the expressions appear to have purely referential occurrence. In 3 and 4, the truth-value of the sentence as a whole depends on whether the referent of ‘The number of planets’ and ‘Nine’ satisfies ‘x is less than eight’. Because the occurrences in 3 and 4 are purely referential but those in 1 and 2 are not, the context ‘John believes that  ’ is a referentially opaque context for the relevant occurrence of at least one of the two singular terms. Some argue that the occurrence of ‘nine’ in 2 is purely referential because the truth-value of the sentence as a whole depends on whether the referent, nine, satisfies the open sentence ‘John believes that x is less than eight’. Saying so requires that we make sense of the concept of satisfaction for such sentences belief sentences and others and that we show that the concept of satisfaction applies in this way in the case at hand sentence 2. There is controversy about whether these things can be done. In 1, on the other hand, the truth-value is not determined by whether nine the referent of ‘the number of planets’ satisfies the open sentence, so that occurrence is not purely referential. Modal contexts raise similar questions. 5 Necessarily, nine is odd. 6 Necessarily, the number of planets is odd. If 5 is true but 6 is not, then at least one of the expressions does not have a purely referential occurrence, even though both appear to be purely referential in the non-modal sentence that appears in the context ‘Necessarily, ———’. Thus the context is referentially opaque for the occurrence of at least one of these terms. On an alternative approach, genuinely singular terms always occur referentially, and ‘the number of planets’ is not a genuinely singular term. Russell’s theory of definite descriptions, e.g., provides an alternative semantic analysis for sentences involving definite descriptions. This would enable us to say that even simple sentences like 3 and 4 differ considerably in syntactic and semantic structure, so that the similarity that suggests the problem, the seemingly similar occurrences of co-referential terms, is merely apparent. 

reflection principles, two varieties of internal statements related to correctness in formal axiomatic systems. 1 Proof-theoretic reflection principles are formulated for effectively presented systems S that contain a modicum of elementary number theory sufficient to arithmetize their own syntactic notions, as done by Kurt Gödel in his 1931 work on incompleteness. Let ProvS x express that x is the Gödel number of a statement provable in S, and let nA be the number of A, for any statement A of S. The weakest reflection principle considered for S is the collection RfnS of all statements of the form ProvS nA P A, which express that if A is provable from S then A is true. The proposition ConS expressing the consistency of S is a consequence of RfnS obtained by taking A to be a disprovable statement. Thus, by Gödel’s second referential occurrence reflection principles 781    781 incompleteness theorem, RfnS is stronger than S if S is consistent. Reflection principles are used in the construction of ordinal logics as a systematic means of overcoming incompleteness. 2 Set-theoretic reflection principles are formulated for systems S of axiomatic set theory, such as ZF Zermelo-Fraenkel. In the simplest form they express that any property A in the language of S that holds of the universe of “all” sets, already holds of a portion of that universe coextensive with some set x. This takes the form A P DxAx where in Ax all quantifiers of A are relativized to x. In contrast to proof-theoretic reflection principles, these may be established as theorems of ZF. 

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reflective equilibrium, as usually conceived, a coherence method for justifying evaluative principles and theories. The method was first described by Goodman, who proposed it be used to justify deductive and inductive principles. According to Goodman Fact, Fiction and Forecast, 1965, a particular deductive inference is justified by its conforming with deductive principles, but these principles are justified in their turn by conforming with accepted deductive practice. The idea, then, is that justified inferences and principles are those that emerge from a process of mutual adjustment, with principles being revised when they sanction inferences we cannot bring ourselves to accept, and particular inferences being rejected when they conflict with rules we are unwilling to revise. Thus, neither principles nor particular inferences are epistemically privileged. At least in principle, everything is liable to revision. Rawls further articulated the method of reflective equilibrium and applied it in ethics. According to Rawls A Theory of Justice, 1971, inquiry begins with considered moral judgments, i.e., judgments about which we are confident and which are free from common sources of error, e.g., ignorance of facts, insufficient reflection, or emotional agitation. According to narrow reflective equilibrium, ethical principles are justified by bringing them into coherence with our considered moral judgments through a process of mutual adjustment. Rawls, however, pursues a wide reflective equilibrium. Wide equilibrium is attained by proceeding to consider alternatives to the moral conception accepted in narrow equilibrium, along with philosophical arguments that might decide among these conceptions. The principles and considered judgments accepted in narrow equilibrium are then adjusted as seems appropriate. One way to conceive of wide reflective equilibrium is as an effort to construct a coherent system of belief by a process of mutual adjustment to considered moral judgments and moral principles as in narrow equilibrium along with the background philosophical, social scientific, and any other relevant beliefs that might figure in the arguments for and against alternative moral conceptions, e.g., metaphysical views regarding the nature of persons. As in Goodman’s original proposal, none of the judgments, principles, or theories involved is privileged: all are open to revision. 

regression analysis, a part of statistical theory concerned with the analysis of data with the aim of inferring a linear functional relationship between assumed independent “regressor” variables and a dependent “response” variable. A typical example involves the dependence of crop yield on the application of fertilizer. For the most part, higher amounts of fertilizer are associated with higher yields. But typically, if crop yield is plotted vertically on a graph with the horizontal axis representing amount of fertilizer applied, the resulting points will not fall

 in a straight line. This can be due either to random “stochastic” fluctuations involving measurement errors, irreproducible conditions, or physical indeterminism or to failure to take into account other relevant independent variables such as amount of rainfall. In any case, from any resulting “scatter diagram,” it is possible mathematically to infer a “best-fitting” line. One method is, roughly, to find the line that minimizes the average absolute distance between a line and the data points collected. More commonly, the average of the squares of these distances is minimized this is the “least squares” method. If more than one independent variable is suspected, the theory of multiple regression, which takes into account mulreflective equilibrium regression analysis 782    782 tiple regressors, can be applied: this can help to minimize an “error term” involved in regression. Computers must be used for the complex computations typically encountered. Care must be taken in connection with the possibility that a lawlike, causal dependence is not really linear even approximately over all ranges of the regressor variables e.g., in certain ranges of amounts of application, more fertilizer is good for a plant, but too much is bad. 

Reichenbach, Hans 18911953, German philosopher of science and a major leader of the movement known as logical empiricism. Born in Hamburg, he studied engineering for a brief time, then turned to mathematics, philosophy, and physics, which he pursued at the universities of Berlin, Munich, and Göttingen. He took his doctorate in philosophy at Erlangen 1915 with a dissertation on mathematical and philosophical aspects of probability, and a degree in mathematics and physics by state examination at Göttingen 1916. In 1933, with Hitler’s rise to power, he fled to Istanbul, then to the  of California at Los Angeles, where he remained until his death. Prior to his departure from Germany he was professor of philosophy of science at the  of Berlin, leader of the Berlin Group of logical empiricists, and a close associate of Einstein. With Carnap he founded Erkenntnis, the major journal of scientific philosophy before World War II. After a short period early in his career as a follower of Kant, Reichenbach rejected the synthetic a priori, chiefly because of considerations arising out of Einstein’s general theory of relativity. He remained thereafter champion of empiricism, adhering to a probabilistic version of the verifiability theory of cognitive meaning. Never, however, did he embrace the logical positivism of the Vienna Circle; indeed, he explicitly described his principal epistemological work, Experience and Prediction 1938, as his refutation of logical positivism. In particular, his logical empiricism consisted in rejecting phenomenalism in favor of physicalism; he rejected phenomenalism both in embracing scientific realism and in insisting on a thoroughgoing probabilistic analysis of scientific meaning and scientific knowledge. His main works span a wide range. In Probability and Induction he advocated the frequency interpretation of probability and offered a pragmatic justification of induction. In his philosophy of space and time he defended conventionality of geometry and of simultaneity. In foundations of quantum mechanics he adopted a three-valued logic to deal with causal anomalies. He wrote major works on epistemology, logic, laws of nature, counterfactuals, and modalities. At the time of his death he had almost completed The Direction of Time, which was published posthumously 1956. 

Reid, Thomas 171096, Scottish philosopher, a defender of common sense and critic of the theory of impressions and ideas articulated by Hume. Reid was born exactly one year before Hume, in Strachan, Scotland. A bright lad, he went to Marischal  in Aberdeen at the age of twelve, studying there with Thomas Blackwell and George Turnbull. The latter apparently had great influence on Reid. Turnbull contended that knowledge of the facts of sense and introspection may not be overturned by reasoning and that volition is the only active power known from experience. Turnbull defended common sense under the cloak of Berkeley. Reid threw off that cloak with considerable panache, but he took over the defense of common sense from Turnbull. Reid moved to a position of regent and lecturer at King’s  in Aberdeen in 1751. There he formed, with John Gregory, the Aberdeen Philosophical Society, which met fortnightly, often to discuss Hume. Reid published his Inquiry into the Human Mind on the Principles of Common Sense in 1764, and, in the same year, succeeded Adam Smith in the chair of moral philosophy at Old  in Glasgow. After 1780 he no longer lectured but devoted himself to his later works, Essays on the Intellectual Powers 1785 and Essays on the Active Powers 1788. He was highly influential in Scotland and on the Continent in the eighteenth century and, from time to time, in England and the United States thereafter. Reid thought that one of his major contributions was the refutation of Hume’s theory of impressions and ideas. Reid probably was convinced in his teens of the truth of Berkeley’s doctrine that what the mind is immediately aware of is always some idea, but his later study of Hume’s Treatise convinced him that, contrary to regressor variable Reid, Thomas 783    783 Berkeley, it was impossible to reconcile this doctrine, the theory of ideas, with common sense. Hume had rigorously developed the theory, Reid said, and drew forth the conclusions. These, Reid averred, were absurd. They included the denial of our knowledge of body and mind, and, even more strikingly, of our conceptions of these things. The reason Reid thought that Hume’s theory of ideas led to these conclusions was that for Hume, ideas were faded impressions of sense, hence, sensations. No sensation is like a quality of a material thing, let alone like the object that has the quality. Consider movement. Movement is a quality of an object wherein the object changes from one place to another, but the visual sensation that arises in us is not the change of place of an object, it is an activity of mind. No two things could, in fact, be more unalike. If what is before the mind is always some sensation, whether vivacious or faded, we should never obtain the conception of something other than a sensation. Hence, we could never even conceive of material objects and their qualities. Even worse, we could not conceive of our own minds, for they are not sensations either, and only sensations are immediately before the mind, according to the theory of ideas. Finally, and even more absurdly, we could not conceive of past sensations or anything that does not now exist. For all that is immediately before the mind is sensations that exist presently. Thus, we could not even conceive of qualities, bodies, minds, and things that do not now exist. But this is absurd, since it is obvious that we do think of all these things and even of things that have never existed. The solution, Reid suggested, is to abandon the theory of ideas and seek a better one. Many have thought Reid was unfair to Hume and misinterpreted him. Reid’s Inquiry was presented to Hume by Dr. Blair in manuscript form, however, and in reply Hume does not at all suggest that he has been misinterpreted or handled unfairly. Whatever the merits of Reid’s criticism of Hume, it was the study of the consequences of Hume’s philosophy that accounts for Reid’s central doctrine of the human faculties and their first principles. Faculties are innate powers, among them the powers of conception and conviction. Reid’s strategy in reply to Hume is to build a nativist theory of conception on the failure of Hume’s theory of ideas. Where the theory of ideas, the doctrine of impressions and ideas, fails to account for our conception of something, of qualities, bodies, minds, past things, nonexistent things, Reid hypothesizes that our conceptions originate from a faculty of the mind, i.e., from an innate power of conception. This line of argument reflects Reid’s respect for Hume, whom he calls the greatest metaphysician of the age, because Hume drew forth the consequences of a theory of conception, which we might call associationism, according to which all our conceptions result from associating sensations. Where the associationism of Hume failed, Reid hypothesized that conceptions arise from innate powers of conception that manifest themselves in accordance with original first principles of the mind. The resulting hypotheses were not treated as a priori necessities but as empirical hypotheses. Reid notes, therefore, that there are marks by which we can discern the operation of an innate first principle, which include the early appearance of the operation, its universality in mankind, and its irresistibility. The operations of the mind that yield our conceptions of qualities, bodies, and minds all bear these marks, Reid contends, and that warrants the conclusion that they manifest first principles. It should be noted that Reid conjectured that nature would be frugal in the implantation of innate powers, supplying us with no more than necessary to produce the conceptions we manifest. Reid is, consequently, a parsimonious empiricist in the development of his nativist psychology. Reid developed his theory of perception in great detail and his development led, surprisingly, to his articulation of non-Euclidean geometry. Indeed, while Kant was erroneously postulating the a priori necessity of Euclidean space, Reid was developing non-Euclidean geometry to account for the empirical features of visual space. Reid’s theory of perception is an example of his empiricism. In the Inquiry, he says that sensations, which are operations of the mind, and impressions on the organs of sense, which are material, produce our conceptions of primary and secondary qualities. Sensations produce our original conceptions of secondary qualities as the causes of those sensations. They are signs that suggest the existence of the qualities. A sensation of smell suggests the existence of a quality in the object that causes the sensation, though the character of the cause is otherwise unknown. Thus, our original conception of secondary qualities is a relative conception of some unknown cause of a sensation. Our conception of primary qualities differs not, as Locke suggested, because of some resemblance between the sensation and the quality for, as Berkeley noted, there is no resemblance between a sensation and quality, but because our original conReid, Thomas Reid, Thomas 784    784 ceptions of primary qualities are clear and distinct. The sensation is a sign that suggests a definite conception of the primary quality, e.g. a definite conception of the movement of the object, rather than a mere conception of something, we know not what, that gives rise to the sensation. These conceptions of qualities signified by sensations result from the operations of principles of our natural constitution. These signs, which suggest the conception of qualities, also suggest a conception of some object that has them. This conception of the object is also relative, in that it is simply a conception of a subject of the qualities. In the case of physical qualities, the conception of the object is a conception of a material object. Though sensations, which are activities of the mind, suggest the existence of qualities, they are not the only signs of sense perception. Some impressions on the organs of sense, the latter being material, also give rise to conceptions of qualities, especially to our conception of visual figure, the seen shape of the object. But Reid can discern no sensation of shape. There are, of course, sensations of color, but he is convinced from the experience of those who have cataracts and see color but not shape that the sensations of color are insufficient to suggest our conceptions of visual figure. His detailed account of vision and especially of the seeing of visual figure leads him to one of his most brilliant moments. He asks what sort of data do we receive upon the eye and answers that the data must be received at the round surface of the eyeball and processed within. Thus, visual space is a projection in three dimensions of the information received on the round surface of the eye, and the geometry of this space is a non-Euclidean geometry of curved space. Reid goes on to derive the properties of the space quite correctly, e.g., in concluding that the angles of a triangle will sum to a figure greater than 180 degrees and thereby violate the parallels postulate. Thus Reid discovered that a non-Euclidean geometry was satisfiable and, indeed, insisted that it accurately described the space of vision not, however, the space of touch, which he thought was Euclidean. From the standpoint of his theory of perceptual signs, the example of visual figure helps to clarify his doctrine of the signs of perception. We do not perceive signs and infer what they signify. This inference, Reid was convinced by Hume, would lack the support of reasoning, and Reid concluded that reasoning was, in this case, superfluous. The information received on the surface of the eye produces our conceptions of visual figure immediately. Indeed, these signs pass unnoticed as they give rise to the conception of visual figure in the mind. The relation of sensory signs to the external things they signify originally is effected by a first principle of the mind without the use of reason. The first principles that yield our conceptions of qualities and objects yield convictions of the existence of these things at the same time. A question naturally arises as to the evidence of these convictions. First principles yield the convictions along with the conceptions, but do we have evidence of the existence of the qualities and objects we are convinced exist? We have the evidence of our senses, of our natural faculties, and that is all the evidence possible here. Reid’s point is that the convictions in questions resulting from the original principles of our faculties are immediately justified. Our faculties are, however, all fallible, so the justification that our original convictions possess may be refuted. We can now better understand Reid’s reply to Hume. To account for our convictions of the existence of body, we must abandon Hume’s theory of ideas, which cannot supply even the conception of body. We must discover both the original first principles that yield the conception and conviction of objects and their qualities, and first principles to account for our convictions of the past, of other thinking beings, and of morals. Just as there are first principles of perception that yield convictions of the existence of presently existing objects, so there are first principles of memory that yield the convictions of the existence of past things, principles of testimony that yield the convictions of the thoughts of others, and principles of morals that yield convictions of our obligations. Reid’s defense of a moral faculty alongside the faculties of perception and memory is striking. The moral faculty yields conceptions of the justice and injustice of an action in response to our conception of that action. Reid shrewdly notes that different people may conceive of the same action in different ways. I may conceive of giving some money as an action of gratitude, while you may consider it squandering money. How we conceive of an action depends on our moral education, but the response of our moral faculty to an action conceived in a specific way is original and the same in all who have the faculty. Hence differences in moral judgment are due, not to principles of the moral faculty, but to differences in how we conceive of our actions. This doctrine of a moral faculty again provides a counterpoint to the moral philosophy of Hume, for, according Reid, Thomas Reid, Thomas 785    785 to Reid, judgments of justice and injustice pertaining to all matters, including promises, contracts, and property, arise from our natural faculties and do not depend on anything artificial. Reid’s strategy for defending common sense is clear enough. He thinks that Hume showed that we cannot arrive at our convictions of external objects, of past events, of the thoughts of others, of morals, or, for that matter, of our own minds, from reasoning about impressions and ideas. Since those convictions are a fact, philosophy must account for them in the only way that remains, by the hypothesis of innate faculties that yield them. But do we have any evidence for these convictions? Evidence, Reid says, is the ground of belief, and our evidence is that of our faculties. Might our faculties deceive us? Reid answers that it is a first principle of our faculties that they are not fallacious. Why should we assume that our faculties are not fallacious? First, the belief is irresistible. However we wage war with first principles, the principles of common sense, they prevail in daily life. There we trust our faculties whether we choose to or not. Second, all philosophy depends on the assumption that our faculties are not fallacious. Here Reid employs an ad hominem argument against Hume, but one with philosophical force. Reid says that, in response to a total skeptic who decides to trust none of his faculties, he puts his hand over his mouth in silence. But Hume trusted reason and consciousness, and therefore is guilty of pragmatic inconsistency in calling the other faculties into doubt. They come from the same shop, Reid says, and he who calls one into doubt has no right to trust the others. All our faculties are fallible, and, therefore, we must, to avoid arbitrary favoritism, trust them all at the outset or trust none. The first principles of our faculties are trustworthy. They not only account for our convictions, but are the ground and evidence of those convictions. This nativism is the original engine of justification. Reid’s theory of original perceptions is supplemented by a theory of acquired perceptions, those which incorporate the effects of habit and association, such as the perception of a passing coach. He distinguishes acquired perceptions from effects of reasoning. The most important way our original perceptions must be supplemented is by general conceptions. These result from a process whereby our attention is directed to some individual quality, e.g., the whiteness of a piece of paper, which he calls abstraction, and a further process of generalizing from the individual quality to the general conception of the universal whiteness shared by many individuals. Reid is a sophisticated nominalist; he says that the only things that exist are individual, but he includes individual qualities as well as individual objects. The reason is that individual qualities obviously exist and are needed as the basis of generalization. To generalize from an individual we must have some conception of what it is like, and this conception cannot be general, on pain of circularity or regress, but must be a conception of an individual quality, e.g., the whiteness of this paper, which it uniquely possesses. Universals, though predicated of objects to articulate our knowledge, do not exist. We can think of universals, just as we can think of centaurs, but though they are the objects of thought and predicated of individuals that exist, they do not themselves exist. Generalization is not driven by ontology but by utility. It is we and not nature that sort things into kinds in ways that are useful to us. This leads to a division-of-labor theory of meaning because general conceptions are the meanings of general words. Thus, in those domains in which there are experts, in science or the law, we defer to the experts concerning the general conceptions that are the most useful in the area in question. Reid’s theory of the intellectual powers, summarized briefly above, is supplemented by his theory of our active powers, those that lead to actions. His theory of the active powers includes a theory of the principles of actions. These include animal principles that operate without understanding, but the most salient and philosophically important part of Reid’s theory of the active powers is his theory of the rational principles of action, which involve understanding and the will. These rational principles are those in which we have a conception of the action to be performed and will its performance. Action thus involves an act of will or volition, but volitions as Reid conceived of them are not the esoteric inventions of philosophy but, instead, the commonplace activities of deciding and resolving to act. Reid is a libertarian and maintains that our liberty or freedom refutes the principle of necessity or determinism. Freedom requires the power to will the action and also the power not to will it. The principle of necessity tells us that our action was necessitated and, therefore, that it was not in our power not to have willed as we did. It is not sufficient for freedom, as Hume suggested, that we act as we will. We must also have the Reid, Thomas Reid, Thomas 786    786 power to determine what we will. The reason is that willing is the means to the end of action, and he who lacks power over the means lacks power over the end. This doctrine of the active power over the determinations of our will is founded on the central principle of Reid’s theory of the active powers, the principle of agent causation. The doctrine of acts of the will or volitions does not lead to a regress, as critics allege, because my act of will is an exercise of the most basic kind of causality, the efficient causality of an agent. I am the efficient cause of my acts of will. My act of will need not be caused by an antecedent act of will because my act of will is the result of my exercise of my causal power. This fact also refutes an objection to the doctrine of liberty  that if my action is not necessitated, then it is fortuitous. My free actions are caused, not fortuitous, though they are not necessitated, because they are caused by me. How, one might inquire, do we know that we are free? The doubt that we are free is like other skeptical doubts, and receives a similar reply, namely, that the conviction of our freedom is a natural and original conviction arising from our faculties. It occurs prior to instruction and it is irresistible in practical life. Any person with two identical coins usable to pay for some item must be convinced that she can pay with the one or the other; and, unlike the ass of Buridan, she readily exercises her power to will the one or the other. The conviction of freedom is an original one, not the invention of philosophy, and it arises from the first principles of our natural faculties, which are trustworthy and not fallacious. The first principles of our faculties hang together like links in a chain, and one must either raise up the whole or the links prove useless. Together, they are the foundation of true philosophy, science, and practical life, and without them we shall lead ourselves into the coalpit of skepticism and despair. 

Reimarus, Hermann Samuel 16941768, German philosopher, born in Hamburg and educated in philosophy and theology at Jena. For most of his life he taught Oriental languages at a high school in Hamburg. The most important writings he published were a treatise on natural religion, Abhandlungen von den vornehmsten Wahrheiten der natürlichen Religion 1754; a textbook on logic, Vernunftlehre 1756; and an interesting work on instincts in animals, Allgemeine Betrachtungen über die Triebe der Tiere 1760. However, he is today best known for his Apologie oder Schutzschrift für die vernünftigen Verehrer Gottes “Apology for or Defense of the Rational Worshipers of God”, posthumously published in 177477. In it, Reimarus reversed his stance on natural theology and openly advocated a deism in the British tradition. The controversy created by its publication had a profound impact on the further development of German theology. Though Reimarus always remained basically a follower of Wolff, he was often quite critical of Wolffian rationalism in his discussion of logic and psychology. 

Reinhold, Karl Leonhard 17431819, Austrian philosopher who was both a popularizer and a critic of Kant. He was the first occupant of the chair of critical philosophy established at the  of Jena in 1787. His Briefe über die Kantische Philosophie 1786/87 helped to popularize Kantianism. Reinhold also proclaimed the need for a more “scientific” presentation of the critical philosophy, in the form of a rigorously deductive system in which everything is derivable from a single first principle “the principle of consciousness”. He tried to satisfy this need with Elementarphilosophie “Elementary Philosophy” or “Philosophy of the Elements”, expounded in his Versuch einer neuen Theorie des menschlichen Vorstellungsvermögens “Attempt at a New Theory of the Human Faculty of Representation,” 1789, Beyträge zur Berichtigung bisheriger Missverständnisse der Philosophen I “Contributions to the Correction of the Prevailing Misunderstandings of Philosophers,” 1790, and Ueber das Fundament des philosophischen Wissens “On the Foundation of Philosophical Knowledge,” 1791. His criticism of the duality of Kant’s starting point and of the ad hoc character of his deductions contributed to the demand for a more coherent exposition of transcendental idealism, while his strategy for accomplishing this task stimulated others above all, Fichte to seek an even more “fundamental” first principle for philosophy. Reinhold later became an enthusiastic adherent, first of Fichte’s Wissenschaftslehre and then of Bardili’s “rational realism,” before finally adopting a novel “linguistic” approach to philosophical problems. 

reism, also called concretism, the theory that the basic entities are concrete objects. Reism differs from nominalism in that the problem of universals is not its only motivation and often not the principal motivation for the theory. Three types of reism can be distinguished. 1 Brentano held that every object is a concrete or individual thing. He said that substances, aggregates of substances, parts of substances, and individual properties of substances are the only things that exist. There is no such thing as the existence or being of an object; and there are no non-existent objects. One consequence of this doctrine is that the object of thought what the thought is about is always an individual object and not a proposition. For example, the thought that this paper is white is about this paper and not about the proposition that this paper is white. Meinong attacked Brentano’s concretism and argued that thoughts are about “objectives,” not objects. 2 Kotarbigski, who coined the term ‘reism’, holds as a basic principle that only concrete objects exist. Although things may be hard or soft, red or blue, there is no such thing as hardness, softness, redness, or blueness. Sentences that contain abstract words are either strictly meaningless or can be paraphrased into sentences that do not contain any abstract words. Kotarbinski is both a nominalist and a materialist. Brentano was a nominalist and a dualist. 3 Thomas Garrigue Masaryk’s concretism is quite different from the first two. For him, concretism is the theory that all of a person’s cognitive faculties participate in every instance of knowing: reason, senses, emotion, and will. 

relation, a two-or-more-place property e.g., loves or between, or the extension of such a property. In set theory, a relation is any set of ordered pairs or triplets, etc., but these are reducible to pairs. For simplicity, the formal exposition here uses the language of set theory, although an intensional property-theoretic view is later assumed. The terms of a relation R are the members of the pairs constituting R, the items that R relates. The collection D of all first terms of pairs in R is the domain of R; any collection with D as a subcollection may also be so called. Similarly, the second terms of these pairs make up or are a subcollection of the range counterdomain or converse domain of R. One usually works within a set U such that R is a subset of the Cartesian product U$U the set of all ordered pairs on U. Relations can be: 1 reflexive or exhibit reflexivity: for all a, aRa. That is, a reflexive relation is one that, like identity, each thing bears to itself. Examples: a weighs as much as b; or the universal relation, i.e., the relation R such that for all a and b, aRb. 2 symmetrical or exhibit symmetry: for all a and b, aRb P bRa. In a symmetrical relation, the order of the terms is reversible. Examples: a is a sibling of b; a and b have a common divisor. Also symmetrical is the null relation, under which no object is related to anything. 3 transitive or exhibit transitivity: for all a, b, and c, aRb & bRc P aRc. Transitive relations carry across a middle term. Examples: a is less than b; a is an ancestor of b. Thus, if a is less than b and b is less than c, a is less than c: less than has carried across the middle term, b. 4 antisymmetrical: for all a and b, aRb & bRa P a % b. 5 trichotomous, connected, or total trichotomy: for all a and b, aRb 7 bRa 7 a % b. 6 asymmetrical: aRb & bRa holds for no a and b. 7 functional: for all a, b, and c, aRb & aRc P b % c. In a functional relation which may also be called a function, each first term uniquely determines a second term. R is non-reflexive if it is not reflexive, i.e., if the condition 1 fails for at least one object a. R is non-symmetric if 2 fails for at least one pair of objects a, b. Analogously for non-transitive. R is irreflexive aliorelative if 1 holds for no object a and intransitive if 3 holds for no objects a, b, and c. Thus understands is non-reflexive since some things do not understand themselves, but not irreflexive, since some things do; loves is nonsymmetric but not asymmetrical; and being a cousin of is non-transitive but not intransitive, as being mother of is. 13 define an equivalence relation e.g., the identity relation among numbers or the relation of being the same age as among people. A class of objects bearing an equivalence relation R to each other is an equivalence class under R. 1, 3, and 4 define a partial order; 3, 5, and 6 a linear order. Similar properties define other important classifications, such as lattice and Boolean algebra. The converse of a relation R is the set of all pairs b, a such that aRb; the comreism relation 788    788 plement of R is the set of all pairs a, b such that aRb i.e. aRb does not hold. A more complex example will show the power of a relational vocabulary. The ancestral of R is the set of all a, b such that either aRb or there are finitely many cI , c2, c3, . . . , cn such that aRcI and c1Rc2 and c2Rc3 and . . . and cnRb. Frege introduced the ancestral in his theory of number: the natural numbers are exactly those objects bearing the ancestral of the successor-of relation to zero. Equivalently, they are the intersection of all sets that contain zero and are closed under the successor relation. This is formalizable in second-order logic. Frege’s idea has many applications. E.g., assume a set U, relation R on U, and property F. An element a of U is hereditarily F with respect to R if a is F and any object b which bears the ancestral of R to a is also F. Hence F is here said to be a hereditary property, and the set a is hereditarily finite with respect to the membership relation if a is finite, its members are, as are the members of its members, etc. The hereditarily finite sets or the sets hereditarily of cardinality ‹ k for any inaccessible k are an important subuniverse of the universe of sets. Philosophical discussions of relations typically involve relations as special cases of properties or sets. Thus nominalists and Platonists disagree over the reality of relations, since they disagree about properties in general. Similarly, one important connection is to formal semantics, where relations are customarily taken as the denotations of relational predicates. Disputes about the notion of essence are also pertinent. One says that a bears an internal relation, R, to b provided a’s standing in R to b is an essential property of a; otherwise a bears an external relation to b. If the essentialaccidental distinction is accepted, then a thing’s essential properties will seem to include certain of its relations to other things, so that we must admit internal relations. Consider a point in space, which has no identity apart from its place in a certain system. Similarly for a number. Or consider my hand, which would perhaps not be the same object if it had not developed as part of my body. If it is true that I could not have had other parents  that possible persons similar to me but with distinct parents would not really be me  then I, too, am internally related to other things, namely my parents. Similar arguments would generate numerous internal relations for organisms, artifacts, and natural objects in general. Internal relations will also seem to exist among properties and relations themselves. Roundness is essentially a kind of shape, and the relation larger than is essentially the converse of the relation smaller than. In like usage, a relation between a and b is intrinsic if it depends just on how a and b are; extrinsic if they have it in virtue of their relation to other things. Thus, higher-than intrinsically relates the Alps to the Appalachians. That I prefer viewing the former to the latter establishes an extrinsic relation between the mountain ranges. Note that this distinction is obscure as is internal-external. One could argue that the Alps are higher than the Appalachians only in virtue of the relation of each to something further, such as space, light rays, or measuring rods. Another issue specific to the theory of relations is whether relations are real, given that properties do exist. That is, someone might reject nominalism only to the extent of admitting one-place properties. Although such doctrines have some historical importance in, e.g., Plato and Bradley, they have disappeared. Since relations are indispensable to modern logic and semantics, their inferiority to one-place properties can no longer be seriously entertained. Hence relations now have little independent significance in philosophy. 

relational logic, the formal study of the properties of and operations on binary relations that was initiated by Peirce between 1870 and 1882. Thus, in relational logic, one might examine the formal properties of special kinds of relations, such as transitive relations, or asymmetrical ones, or orderings of certain types. Or the focus might be on various operations, such as that of forming the converse or relative product. Formal deductive systems used in such studies are generally known as calculi of relations. 

relativism, the denial that there are certain kinds of universal truths. There are two main types, cognitive and ethical. Cognitive relativism holds that there are no universal truths about the world: the world has no intrinsic characteristics, there are just different ways of interpreting it. The Grecian Sophist Protagoras, the first person on record to hold such a view, said, “Man is the measure of all things; of things that are that they are, and of things that are not that they are not.” Goodman, Putnam, and Rorty are contemporary philosophers who have held versions of relativism. Rorty says, e.g., that “ ‘objective truth’ is no more and no less than the best idea we currently have about how to explain what is going on.” Critics of cognitive relativism contend that it is self-referentially incoherent, since it presents its statements as universally true, rather than simply relatively so. Ethical relativism is the theory that there are no universally valid moral principles: all moral principles are valid relative to culture or individual choice. There are two subtypes: conventionalism, which holds that moral principles are valid relative to the conventions of a given culture or society; and subjectivism, which maintains that individual choices are what determine the validity of a moral principle. Its motto is, Morality lies in the eyes of the beholder. As Ernest Hemingway wrote, “So far, about morals, I know only that what is moral is what you feel good after and what is immoral is what you feel bad after.” Conventionalist ethical relativism consists of two theses: a diversity thesis, which specifies that what is considered morally right and wrong varies from society to society, so that there are no moral principles accepted by all societies; and a dependency thesis, which specifies that all moral principles derive their validity from cultural acceptance. From these two ideas relativists conclude that there are no universally valid moral principles applying everywhere and at all times. The first thesis, the diversity thesis, or what may simply be called cultural relativism, is anthropological; it registers the fact that moral rules differ from society to society. Although both ethical relativists and non-relativists typically accept cultural relativism, it is often confused with the normative thesis of ethical relativism. The opposite of ethical relativism is ethical objectivism, which asserts that although cultures may differ in their moral principles, some moral principles have universal validity. Even if, e.g., a culture does not recognize a duty to refrain from gratuitous harm, that principle is valid and the culture should adhere to it. There are two types of ethical objectivism, strong and weak. Strong objectivism, sometimes called absolutism, holds that there is one true moral system with specific moral rules. The ethics of ancient Israel in the Old Testament with its hundreds of laws exemplifies absolutism. Weak objectivism holds that there is a core morality, a determinate set of principles that are universally valid usually including prohibitions against killing the innocent, stealing, breaking of promises, and lying. But weak objectivism accepts an indeterminate area where relativism is legitimate, e.g., rules regarding sexual mores and regulations of property. Both types of objectivism recognize what might be called application relativism, the endeavor to apply moral rules where there is a conflict between rules or where rules can be applied in different ways. For example, the ancient Callactians ate their deceased parents but eschewed the impersonal practice of burying them as disrespectful, whereas contemporary society has the opposite attitudes about the care of dead relatives; but both practices exemplify the same principle of the respect for the dead. According to objectivism, cultures or forms of life can fail to exemplify an adequate moral community in at least three ways: 1 the people are insufficiently intelligent to put constitutive principles in order; 2 they are under considerable stress so that it becomes too burdensome to live by moral principles; and 3 a combination of 1 and 2. Ethical relativism is sometimes confused with ethical skepticism, the view that we cannot know whether there are any valid moral principles. Ethical nihilism holds that there are no valid moral principles. J. L. Mackie’s error theory is a version of this view. Mackie held that while we all believe some moral principles to be true, there are compelling arguments to the contrary. Ethical objectivism must be distinguished from moral realism, the view that valid moral principles are true, independently of human choice. Objectivism may be a form of ethical constructivism, typified by Rawls, whereby objective principles are simply those that impartial human beings would choose behind the veil of ignorance. That is, the principles are not truly independent of hypothetical human choices, but are constructs from those choices. 

relativity, a term applied to Einstein’s theories of electrodynamics special relativity, 1905 and gravitation general relativity, 1916 because both hold that certain physical quantities, formerly considered objective, are actually “relative to” the state of motion of the observer. They are called “special” and “general” because, in special relativity, electrodynamical laws determine a restricted class of kinematical reference frames, the “inertial frames”; in general relativity, the very distinction between inertial frames and others becomes a relative distinction. Special relativity. Classical mechanics makes no distinction between uniform motion and rest: not velocity, but acceleration is physically detectable, and so different states of uniform motion are physically equivalent. But classical electrodynamics describes light as wave motion with a constant velocity through a medium, the “ether.” It follows that the measured velocity of light should depend on the motion of the observer relative to the medium. When interferometer experiments suggested that the velocity of light is independent of the motion of the source, H. A. Lorentz proposed that objects in motion contract in the direction of motion through the ether while their local time “dilates”, and that this effect masks the difference in the velocity of light. Einstein, however, associated the interferometry results with many other indications that the theoretical distinction between uniform motion and rest in the ether lacks empirical content. He therefore postulated that, in electrodynamics as in mechanics, all states of uniform motion are equivalent. To explain the apparent paradox that observers with different velocities can agree on the velocity of light, he criticized the idea of an “absolute” or frame-independent measure of simultaneity: simultaneity of distant events can only be established by some kind of signaling, but experiment suggested that light is the only signal with an invariant velocity, and observers in relative motion who determine simultaneity with light signals obtain different results. Furthermore, since objective measurement of time and length presupposes absolute simultaneity, observers in relative motion will also disagree on time and length. So Lorentz’s contraction and dilatation are not physical effects, but consequences of the relativity of simultaneity, length, and time, to the motion of the observer. But this relativity follows from the invariance of the laws of electrodynamics, and the invariant content of the theory is expressed geometrically in Minkowski spacetime. Logical empiricists took the theory as an illustration of how epistemological analysis of a concept time could eliminate empirically superfluous notions absolute simultaneity. General relativity. Special relativity made the velocity of light a limit for all causal processes and required revision of Newton’s theory of gravity as an instantaneous action at a distance. General relativity incorporates gravity into the geometry of space-time: instead of acting directly on one another, masses induce curvature in space-time. Thus the paths of falling bodies represent not forced deviations from the straight paths of a flat space-time, but “straightest” paths in a curved space-time. While space-time is “locally” Minkowskian, its global structure depends on mass-energy distribution. The insight behind this theory is the equivalence of gravitational and inertial mass: since a given gravitational field affects all bodies equally, weight is indistinguishable from the inertial force of acceleration; freefall motion is indistinguishable from inertial motion. This suggests that the Newtonian decomposition of free fall into inertial and accelerated components is arbitrary, and that the freefall path itself is the invariant basis for the structure of space-time. A philosophical motive for the general theory was to extend the relativity of motion. Einstein saw special relativity’s restricted class of equivalent reference frames as an “epistemological defect,” and he sought laws that would apply to any frame. His inspiration was Mach’s criticism of the Newtonian distinction between “absolute” rotation and rotation relative to observable bodies like the “fixed stars.” Einstein formulated Mach’s criticism as a fundamental principle: since only relative motions are observable, local inertial effects should be explained by the cosmic distribution of masses and by motion relative to them. Thus not only velocity and rest, but motion in general would be relative. Einstein hoped to effect this generalization by eliminating the distinction between inertial frames and freely falling frames. Because free fall remains a privileged state of motion, however, non-gravitational acceleration remains detectable, and absolute rotation remains distinct from relative rotation. Einstein also thought that relativity of motion would result from the general covariance coordinate-independence of his theory  i.e., that general equivalence of coordinate systems meant general equivalence relativism, scientific relativity 791    791 of states of motion. It is now clear, however, that general covariance is a mathematical property of physical theories without direct implications about motion. So general relativity does not “generalize” the relativity of motion as Einstein intended. Its great accomplishments are the unification of gravity and geometry and the generalization of special relativity to space-times of arbitrary curvature, which has made possible the modern investigation of cosmological structure. 

relevance logic, any of a range of logics and philosophies of logic united by their insistence that the premises of a valid inference must be relevant to the conclusion. Standard, or classical, logic contains inferences that break this requirement, e.g., the spread law, that from a contradiction any proposition whatsoever follows. Relevance logic had its genesis in a system of strenge Implikation published by Wilhelm Ackermann in 1956. Ackermann’s idea for rejecting irrelevance was taken up and developed by Alan Anderson and Nuel Belnap in a series of papers between 1959 and Anderson’s death in 1974. The first main summaries of these researches appeared under their names, and those of many collaborators, in Entailment: The Logic of Relevance and Necessity vol. 1, 1975; vol. 2, 1992. By the time of Anderson’s death, a substantial research effort into relevance logic was under way, and it has continued. Besides the rather vague unity of the idea of relevance between premises and conclusion, there is a technical criterion often used to mark out relevance logic, introduced by Belnap in 1960, and applicable really only to propositional logics the main focus of concern to date: a necessary condition of relevance is that premises and conclusion should share a propositional variable. Early attention was focused on systems E of entailment and T of ticket entailment. Both are subsystems of C. I. Lewis’s system S4 of strict implication and of classical truth-functional logic i.e., consequences in E and T in ‘P’ are consequences in S4 in ‘ ’ and in classical logic in ‘/’. Besides rejection of the spread law, probably the most notorious inference that is rejected is disjunctive syllogism DS for extensional disjunction which is equivalent to detachment for material implication: A 7 B,ÝA , B. The reason is immediate, given acceptance of Simplification and Addition: Simplification takes us from A & ÝA to each conjunct, and Addition turns the first conjunct into A 7 B. Unless DS were rejected, the spread law would follow. Since the late 1960s, attention has shifted to the system R of relevant implication, which adds permutation to E, to mingle systems which extend E and R by the mingle law A P A P A, and to contraction-free logics, which additionally reject contraction, in one form reading A P A P B P A P B. R minus contraction RW differs from linear logic, much studied recently in computer science, only by accepting the distribution of ‘&’ over ‘7’, which the latter rejects. Like linear logic, relevance logic contains both truth-functional and non-truth-functional connectives. Unlike linear logic, however, R, E, and T are undecidable unusual among propositional logics. This result was obtained only in 1984. In the early 1970s, relevance logics were given possible-worlds semantics by several authors working independently. They also have axiomatic, natural deduction, and sequent or consecution formulations. One technical result that has attracted attention has been the demonstration that, although relevance logics reject DS, they all accept Ackermann’s rule Gamma: that if A 7 B and ÝA are theses, so is B. A recent result occasioning much surprise was that relevant arithmetic consisting of Peano’s postulates on the base of quantified R does not admit Gamma. 

reliabilism, a type of theory in epistemology that holds that what qualifies a belief as knowledge or as epistemically justified is its reliable linkage to the truth. David Armstrong motivates reliabilism with an analogy between a thermometer that reliably indicates the temperature and a belief that reliably indicates the truth. A belief qualifies as knowledge, he says, if there is a lawlike connection in nature that guarantees that the belief is true. A cousin of the nomic sufficiency account is the counterfactual approach, proposed by Dretske, Goldman, and Nozick. A typical formulation of this approach says that a belief qualifies relativity, general reliabilism 792    792 as knowledge if the belief is true and the cognizer has reasons for believing it that would not obtain unless it were true. For example, someone knows that the telephone is ringing if he believes this, it is true, and he has a specific auditory experience that would not occur unless the telephone were ringing. In a slightly different formulation, someone knows a proposition if he believes it, it is true, and if it were not true he would not believe it. In the example, if the telephone were not ringing, he would not believe that it is, because he would not have the same auditory experience. These accounts are guided by the idea that to know a proposition it is not sufficient that the belief be “accidentally” true. Rather, the belief, or its mode of acquisition, must “track,” “hook up with,” or “indicate” the truth. Unlike knowledge, justified belief need not guarantee or be “hooked up” with the truth, for a justified belief need not itself be true. Nonetheless, reliabilists insist that the concept of justified belief also has a connection with truth acquisition. According to Goldman’s reliable process account, a belief’s justificational status depends on the psychological processes that produce or sustain it. Justified beliefs are produced by appropriate psychological processes, unjustified beliefs by inappropriate processes. For example, beliefs produced or preserved by perception, memory, introspection, and “good” reasoning are justified, whereas beliefs produced by hunch, wishful thinking, or “bad” reasoning are unjustified. Why are the first group of processes appropriate and the second inappropriate? The difference appears to lie in their reliability. Among the beliefs produced by perception, introspection, or “good” reasoning, a high proportion are true; but only a low proportion of beliefs produced by hunch, wishful thinking, or “bad” reasoning are true. Thus, what qualifies a belief as justified is its being the outcome of a sequence of reliable belief-forming processes. Reliabilism is a species of epistemological externalism, because it makes knowledge or justification depend on factors such as truth connections or truth ratios that are outside the cognizer’s mind and not necessarily accessible to him. Yet reliabilism typically emphasizes internal factors as well, e.g., the cognitive processes responsible for a belief. Process reliabilism is a form of naturalistic epistemology because it centers on cognitive operations and thereby paves the way for cognitive psychology to play a role in epistemology.

Renouvier, Charles 18151903, French philosopher influenced by Kant and Comte, the latter being one of his teachers. Renouvier rejected many of the views of both these philosophers, however, charting his own course. He emphasized the irreducible plurality and individuality of all things against the contemporary tendencies toward absolute idealism. Human individuality he associated with indeterminism and freedom. To the extent that agents are undetermined by other things and self-determining, they are unique individuals. Indeterminism also extends to the physical world and to knowledge. He rejected absolute certitude, but defended the universality of the laws of logic and mathematics. In politics and religion, he emphasized individual freedom and freedom of conscience. His emphasis on plurality, indeterminism, freedom, novelty, and process influenced James and, through James, American pragmatism. 

rerum natura Latin, ‘the nature of things’, metaphysics. The phrase can also be used more narrowly to mean the nature of physical reality, and often it presupposes a naturalistic view of all religion, natural rerum natura 793    793 reality. Lucretius’s epic poem De rerum natura is an Epicurean physics, designed to underpin the Epicurean morality.

responsibility, a condition that relates an agent to actions of, and consequences connected to, that agent, and is always necessary and sometimes sufficient for the appropriateness of certain kinds of appraisals of that agent. Responsibility has no single definition, but is several closely connected specific concepts. Role responsibility. Agents are identified by social roles that they occupy, say parent or professor. Typically duties are associated with such roles  to care for the needs of their children, to attend classes and publish research papers. A person in a social role is “responsible for” the execution of those duties. One who carries out such duties is “a responsible person” or “is behaving responsibly.” Causal responsibility. Events, including but not limited to human actions, cause other events. The cause is “responsible” for the effect. Causal responsibility does not imply consciousness; objects and natural phenomena may have causal responsibility. Liability responsibility. Practices of praise and blame include constraints on the mental stance that an agent must have toward an action or a consequence of action, in order for praise or blame to be appropriate. To meet such constraints is to meet a fundamental necessary condition for liability for praise or blame  hence the expression ‘liability responsibility’. These constraints include such factors as intention, knowledge, recklessness toward consequences, absence of mistake, accident, inevitability of choice. An agent with the capability for liability responsibility may lack it on some occasion  when mistaken, for example. Capacity responsibility. Practices of praise and blame assume a level of intellectual and emotional capability. The severely mentally disadvantaged or the very young, for example, do not have the capacity to meet the conditions for liability responsibility. They are not “responsible” in that they lack capacity responsibility. Both morality and law embody and respect these distinctions, though law institutionalizes and formalizes them. Final or “bottom-line” assignment of responsibility equivalent to indeed deserving praise or blame standardly requires each of the latter three specific kinds of responsibility. The first kind supplies some normative standards for praise or blame. 

resultance, a relation according to which one property the resultant property, sometimes called the consequential property is possessed by some object or event in virtue of and hence as a result of that object or event possessing some other property or set of properties. The idea is that properties of things can be ordered into connected levels, some being more basic than and giving rise to others, the latter resulting from the former. For instance, a figure possesses the property of being a triangle in virtue of its possessing a collection of properties, including being a plane figure, having three sides, and so on; the former resulting from the latter. An object is brittle has the property of being brittle in virtue of having a certain molecular structure. It is often claimed that moral properties like rightness and goodness are resultant properties: an action is right in virtue of its possessing other properties. These examples make it clear that the nature of the necessary connection holding between a resultant property and those base properties that ground it may differ from case to case. In the geometrical example, the very concept of being a triangle grounds the resultance relation in question, and while brittleness is nomologically related to the base properties from which it results, in the moral case, the resultance relation is arguably neither conceptual nor causal. 

Richard Rufus, also called Richard of Cornwall d. c.1260, English philosopher-theologian who wrote some of the earliest commentaries on Aristotle in the Latin West. His commentaries were not cursory summaries; they included sustained philosophical discussions. Richard was a master of arts at Paris, where he studied with Alexander of Hales; he was also deeply influenced by Robert Grosseteste. He left Paris and joined the Franciscan order in 1238; he was ordained in England. In 1256, he became regent master of the Franciscan studium at Oxford; according to Roger Bacon, he was the most influential philosophical theologian at Oxford in the second half of the thirteenth century. In addition to his Aristotle commentaries, Richard wrote two commentaries on Peter Lombard’s Sentences c.1250, c.1254. In the first of these he borrowed freely from Robert Grosseteste, Alexander of Hales, and Richard Fishacre; the second commentary was a critical condensation of the lectures of his younger contemporary, St. Bonaventure, presented in Paris. Richard Rufus was the first medieval proponent of the theory of impetus; his views on projectile motion were cited by Franciscus Meyronnes. He also advocated other arguments first presented by Johannes Philoponus. Against the eternity of the world, he argued: 1 past time is necessarily finite, since it has been traversed, and 2 the world is not eternal, since if the world had no beginning, no more time would transpire before tomorrow than before today. He also argued that if the world had not be

en created ex nihilo, the first cause would be mutable. Robert Grosseteste cited one of Richard’s arguments against the eternity of the world in his notes on Aristotle’s Physics. In theology, Richard denied the validity of Anselm’s ontological argument, but, anticipating Duns Scotus, he argued that the existence of an independent being could be inferred from its possibility. Like Duns Scotus, he employs the formal distinction as an explanatory tool; in presenting his own views, Duns Scotus cited Richard’s definition of the formal distinction. Richard stated his philosophical views briefly, even cryptically; his Latin prose style is sometimes eccentric, characterized by interjections in which he addresses questions to God, himself, and his readers. He was hesitant about the value of systematic theology for the theologian, deferring to biblical exposition as the primary forum for theological discussion. In systematic theology, he emphasized Aristotelian philosophy and logic. He was a well-known logician; some scholars believe he is the famous logician known as the Magister Abstractionum. Though he borrowed freely from his contemporaries, he was a profoundly original philosopher. 

Ricoeur, Paul b.1913, French hermeneuticist and phenomenologist who has been a professor at several French universities as well as the  of Naples, Yale , and the  of Chicago. He has received major prizes from France, Germany, and Italy. He is the author of twenty-some volumes translated in a variety of languages. Among his best-known books are Freedom and Nature: The Voluntary and the Involuntary; Freud and Philosophy: An Essay of Interpretation; The Conflict of Interpretations: Essay in Hermeneutics; The Role of the Metaphor: Multi-Disciplinary Studies of the Creation of Meaning in Language, Time and Narrative; and Oneself as Another. His early studies with the French existentialist Marcel resulted in a book-length study of Marcel’s work and later a series of published dialogues with him. Ricoeur’s philosophical enterprise is colored by a continuing tension between faith and reason. His long-standing commitments to both the significance of the individual and the Christian faith are reflected in his hermeneutical voyage, his commitment to the Esprit movement, and his interest in the writings of Emmanuel Mounier. This latter point is also seen in his claim of the inseparability of action and disretributive justice Ricoeur, Paul 795    795 course in our quest for meaning. In our comprehension of both history and fiction one must turn to the text to understand its plot as guideline if we are to comprehend experience of any reflective sort. In the end there are no metaphysical or epistemological grounds by which meaning can be verified, and yet our nature is such that possibility must be present before us. Ricoeur attempts his explanation through a hermeneutic phenomenology. The very hermeneutics of existence that follows is itself limited by reason’s questioning of experience and its attempts to transcend the limit through the language of symbols and metaphors. Freedom and meaning come to be realized in the actualization of an ethics that arises out of the very act of existing and thus transcends the mere natural voluntary distinction of a formal ethic. It is clear from his later work that he rejects any form of foundationalism including phenomenology as well as nihilism and easy skepticism. Through a sort of interdependent dialectic that goes beyond the more mechanical models of Hegelianism or Marxism, the self understands itself and is understood by the other in terms of its suffering and its moral actions. 

rights, advantageous positions conferred on some possessor by law, morals, rules, or other norms. There is no agreement on the sense in which rights are advantages. Will theories hold that rights favor the will of the possessor over the conflicting will of some other party; interest theories maintain that rights serve to protect or promote the interests of the right-holder. Hohfeld identified four legal advantages: liberties, claims, powers, and immunities. The concept of a right arose in Roman jurisprudence and was extended to ethics via natural law theory. Just as positive law, the law posited by human lawmakers, confers legal rights, so the natural law confers natural rights. Rights are classified by their specific sources in different sorts of rules. Legal rights are advantageous positions under the law of a society. Other species of institutional rights are conferred by the rules of private organizations, of the moral code of a society, or even of some game. Those who identify natural law with the moral law often identify natural rights with moral rights, but some limit natural rights to our most fundamental rights and contrast them with ordinary moral rights. Others deny that moral rights are natural because they believe that they are conferred by the mores or positive morality of one’s society. One always possesses any specific right by virtue of possessing some status. Thus, rights are also classified by status. Civil rights are those one possesses as a citizen; human rights are possessed by virtue of being human. Presumably women’s rights, children’s rights, patients’ rights, and the rights of blacks as such are analogous. Human rights play very much the same role in ethics once played by natural rights. This is partly because ontological doubts about the existence of God undermine the acceptance of any natural law taken to consist in divine commands, and epistemological doubts about self-evident moral truths lead many to reject any natural law conceived of as the dictates of reason. Although the Thomistic view that natural rights are grounded on the nature of man is often advocated, most moral philosophers reject its teleological conception of human nature defined by essential human purposes. It seems simpler to appeal instead to fundamental rights that must be universal among human beings because they are possessed merely by virtue of one’s status as a human being. Human rights are still thought of as natural in the very broad sense of existing independently of any human action or institution. This explains how they can be used as an independent standard in terms of which to criticize the laws and policies of governments and other organizations. Since human rights are classified by status rather than source, there is another species of human rights that are institutional rather than natural. These are the human rights that have been incorporated into legal systems by international agreements such as the European Convention on Human Rights. It is sometimes said that while natural rights were conceived as purely negative rights, such as the right not to be arbitrarily imprisoned, human rights are conceived more broadly to include positive social and economic rights, such as the Riemann, G. F. B. rights 796    796 right to social security or to an adequate standard of living. But this is surely not true by definition. Traditional natural law theorists such as Grotius and Locke spoke of natural rights as powers and associated them with liberties, rather than with claims against interference. And while modern declarations of human rights typically include social and economic rights, they assume that these are rights in the same sense that traditional political rights are. Rights are often classified by their formal properties. For example, the right not to be battered is a negative right because it imposes a negative duty not to batter, while the creditor’s right to be repaid is a positive right because it imposes a positive duty to repay. The right to be repaid is also a passive right because its content is properly formulated in the passive voice, while the right to defend oneself is an active right because its content is best stated in the active voice. Again, a right in rem is a right that holds against all second parties; a right in personam is a right that holds against one or a few others. This is not quite Hart’s distinction between general and special rights, rights of everyone against everyone, such as the right to free speech, and rights arising from special relations, such as that between creditor and debtor or husband and wife. Rights are conceptually contrasted with duties because rights are advantages while duties are disadvantages. Still, many jurists and philosophers have held that rights and duties are logical correlatives. This does seem to be true of claim rights; thus, the creditor’s right to be repaid implies the debtor’s duty to repay and vice versa. But the logical correlative of a liberty right, such as one’s right to park in front of one’s house, is the absence of any duty for one not to do so. This contrast is indicated by D. D. Raphael’s distinction between rights of recipience and rights of action. Sometimes to say that one has a right to do something is to say merely that it is not wrong for one to act in this way. This has been called the weak sense of ‘a right’. More often to assert that one has a right to do something does not imply that exercising this right is right. Thus, I might have a right to refuse to do a favor for a friend even though it would be wrong for me to do so. Finally, many philosophers distinguish between absolute and prima facie rights. An absolute right always holds, i.e., disadvantages some second party, within its scope; a prima facie right is one that holds unless the ground of the right is outweighed by some stronger contrary reason. 

rigorism, the view that morality consists in that single set of simple or unqualified moral rules, discoverable by reason, which applies to all human beings at all times. It is often said that Kant’s doctrine of the categorical imperative is rigoristic. Two main objections to rigorism are 1 some moral rules do not apply universally  e.g., ‘Promises should be kept’ applies only where there is an institution of promising; and 2 some rules that could be universally kept are absurd  e.g., that everyone should stand on one leg while the sun rises. Recent interpreters of Kant defend him against these objections by arguing, e.g., that the “rules” he had in mind are general guidelines for living well, which are in fact universal and practically relevant, or that he was not a rigorist at all, seeing moral worth as issuing primarily from the agent’s character rather than adherence to rules.

ring of Gyges, a ring that gives its wearer invisibility, discussed in Plato’s Republic II, 359b 360d. Glaucon tells the story of a man who discovered the ring and used it to usurp the throne to defend the claim that those who behave justly do so only because they lack the power to act unjustly. If they could avoid paying the penalty of injustice, Glaucon argues, everyone would be unjust. 

Rorty, Richard b.1931, American philosopher, notable for the breadth of his philosophical and cultural interests. He was educated at the  of Chicago and Yale and has taught at rights, Hohfeldian Rorty, Richard 797    797 Wellesley, Princeton, the  of Virginia, and Stanford. His early work was primarily in standard areas of analytic philosophy such as the philosophy of mind, where, for example, he developed an important defense of eliminative materialism. In 1979, however, he published Philosophy and the Mirror of Nature, which was both hailed and denounced as a fundamental critique of analytic philosophy. Both the praise and the abuse were often based on misconceptions, but there is no doubt that Rorty questioned fundamental presuppositions of many Anglo-American philosophers and showed affinities for Continental alternatives to analytic philosophy. At root, however, Rorty’s position is neither analytic except in its stylistic clarity nor Continental except in its cultural breadth. His view is, rather, pragmatic, a contemporary incarnation of the distinctively American philosophizing of James, Peirce, and Dewey. On Rorty’s reading, pragmatism involves a rejection of the representationalism that has dominated modern philosophy from Descartes through logical positivism. According to representationalism, we have direct access only to ideas that represent the world, not to the world itself. Philosophy has the privileged role of determining the criteria for judging that our representations are adequate to reality. A main thrust of Philosophy and the Mirror of Nature is to discredit representationalism, first by showing how it has functioned as an unjustified presupposition in classical modern philosophers such as Descartes, Locke, and Kant, and second by showing how analytic philosophers such as Wilfrid Sellars and Quine have revealed the incoherence of representationalist assumptions in contemporary epistemology. Since, on Rorty’s view, representationalism defines the epistemological project of modern philosophy, its failure requires that we abandon this project and, with it, traditional pretensions to a privileged cognitive role for philosophy. Rorty sees no point in seeking a non-representationalist basis for the justification or the truth of our knowledge claims. It is enough to accept as justified beliefs those on which our epistemic community agrees and to use ‘true’ as an honorific term for beliefs that we see as “justified to the hilt.” Rorty characterizes his positive position as “liberal ironism.” His liberalism is of a standard sort, taking as its basic value the freedom of all individuals: first, their freedom from suffering, but then also freedom to form their lives with whatever values they find most compelling. Rorty distinguishes the “public sphere” in which we all share the liberal commitment to universal freedom from the “private spheres” in which we all work out our own specific conception of the good. His ironism reflects his realization that there is no grounding for public or private values other than our deep but contingent commitment to them and his appreciation of the multitude of private values that he does not himself happen to share. Rorty has emphasized the importance of literature and literary criticism  as opposed to traditional philosophy  for providing the citizens of a liberal society with appropriate sensitivities to the needs and values of others. 

Roscelin de Compiègne c.1050c.1125, French philosopher and logician who became embroiled in theological controversy when he applied his logical teachings to the doctrine of the Trinity. Since almost nothing survives of his written work, we must rely on hostile accounts of his views by Anselm of Canterbury and Peter Abelard, both of whom openly opposed his positions. Perhaps the most notorious view Roscelin is said to have held is that universals are merely the puffs of air produced when a word is pronounced. On this point he opposed views current among many theologians that a universal has an existence independent of language, and somehow is what many different particulars are. Roscelin’s aversion to any proposal that different things can be some one thing is probably what led him in his thinking about the three persons of God to a position that sounded suspiciously like the heresy of tritheism. Roscelin also evidently held that the qualities of things are not entities distinct from the subjects that possess them. This indicates that Roscelin probably denied that terms in the Aristotelian categories other than substance signified anything distinct from substances. Abelard, the foremost logician of the twelfth century, studied under Roscelin around 1095 and was undoubtedly influenced by him on the question of universals. Roscelin’s view that universals are linguistic entities remained an important option in medieval thought. Otherwise his positions do not appear to have had much currency in the ensuing decades. 

Rosenzweig, Franz 18861929, German phiRoscelin de Compiègne Rosenzweig, Franz 798    798 losopher and Jewish theologian known as one of the founders of religious existentialism. His early relation to Judaism was tenuous, and at one point he came close to converting to Christianity. A religious experience in a synagogue made him change his mind and return to Judaism. His chief philosophic works are a two-volume study, Hegel and the State 1920, and his masterpiece, The Star of Redemption 1921. Rosenzweig’s experience in World War I caused him to reject absolute idealism on the ground that it cannot account for the privacy and finality of death. Instead of looking for a unifying principle behind existence, Rosenzweig starts with three independent realities “given” in experience: God, the self, and the world. Calling his method “radical empiricism,” he explains how God, the self, and the world are connected by three primary relations: creation, revelation, and redemption. In revelation, God does not communicate verbal statements but merely a presence that calls for love and devotion from worshipers.

Rosmini-Serbati, Antonio 17971855, Italian philosopher, Catholic priest, counselor to Pope Pius IX, and supporter of the supremacy of the church over civil government Neo-Guelphism. Rosmini had two major concerns: the objectivity of human knowledge and the synthesis of philosophical thought within the tradition of Catholic thought. In his Nuovo saggio sull’origine delle idee “New Essay on the Origin of Ideas,” 1830, he identifies the universal a priori intuitive component of all human knowledge with the idea of being that gives us the notion of a possible or ideal being. Everything in the world is known by intellectual perception, which is the synthesis of sensation and the idea of being. Except for the idea of being, which is directly given by God, all ideas derive from abstraction. The objectivity of human knowledge rests on its universal origin in the idea of being. The harmony between philosophy and religion comes from the fact that all human knowledge is the result of divine revelation. Rosmini’s thought was influenced by Augustine and Aquinas, and stimulated by the attempt to find a solution to the contrasting needs of rationalism and empiricism.

Ross, William David 18771971, British Aristotelian scholar and moral philosopher. Born in Edinburgh and educated at the  of Edinburgh and at Balliol , Oxford, he became a fellow of Merton , then a fellow, tutor, and eventually provost at Oriel . He was vice-chancellor of Oxford  194144 and president of the British Academy 193640. He was knighted in 1938 in view of national service. Ross was a distinguished classical scholar: he edited the Oxford translations of Aristotle 190831 and translated the Metaphysics and the Ethics himself. His Aristotle 1923 is a judicious exposition of Aristotle’s work as a whole. Kant’s Ethical Theory 1954 is a commentary on Kant’s The Groundwork of Ethics. His major contribution to philosophy was in ethics: The Right and the Good 1930 and Foundations of Ethics1939. The view he expressed there was controversial in English-speaking countries for ten years or so. He held that ‘right’ and ‘good’ are empirically indefinable terms that name objective properties the presence of which is known intuitively by persons who are mature and educated. We first cognize them in particular instances, then arrive at general principles involving them by “intuitive induction.” He thought every ethical theory must admit at least one intuition. The knowledge of moral principles is thus rather like knowledge of the principles of geometry. ‘Right’ ‘dutiful’ applies to acts, in the sense of what an agent brings about and there is no duty to act from a good motive, and a right act can have a bad motive; ‘morally good’ applies primarily to the desires that bring about action. He castigated utilitarianism as absorbing all duties into enhancing the wellbeing of everyone affected, whereas in fact we have strong special obligations to keep promises, make reparation for injuries, repay services done, distribute happiness in accord with merit, benefit individuals generally and he concedes this is a weighty matter and ourselves only in respect of knowledge and virtue, and not injure others normally a stronger obligation than that to benefit. That we have these “prima facie” duties is self-evident, but they are only prima facie in the sense that they are actual duties only if there is no stronger conflicting prima facie duty; and when prima facie duties conflict, what one ought to do is what satisfies all of them best  although which this is is a matter of judgment, not self-evidence. He conceded, however, in contrast to his general critique of utilitarianism, that public support of these prima facie principles with their intuitive strength can be justified on utilitarian grounds. To meet various counterexamples Ross introduced complications, such as that a promise is not binding if disRosmini-Serbati, Antonio Ross, William David 799    799 charge of it will not benefit the promisee providing this was an implicit understanding, and it is less binding if made long ago or in a casual manner. Only four states of affairs are good in themselves: desire to do one’s duty virtue, knowledge, pleasure, and the distribution of happiness in accordance with desert. Of these, virtue is more valuable than any amount of knowledge or pleasure. In Foundations of Ethics he held that virtue and pleasure are not good in the same sense: virtue is “admirable” but pleasure only a “worthy object of satisfaction” so ‘good’ does not name just one property. 

Rousseau, Jean-Jacques 171278, Swiss-born French philosopher, essayist, novelist, and musician, best known for his theories on social freedom and societal rights, education, and religion. Born in Geneva, he was largely self-educated and moved to France as a teenager. Throughout much of his life he moved between Paris and the provinces with several trips abroad including a Scottish stay with Hume and a return visit to Geneva, where he reconverted to Protestantism from his earlier conversion to Catholicism. For a time he was a friend of Diderot and other philosophes and was asked to contribute articles on music for the Encyclopedia. Rousseau’s work can be seen from at least three perspectives. As social contract theorist, he attempts to construct a hypothetical state of nature to explain the current human situation. This evolves a form of philosophical anthropology that gives us both a theory of human nature and a series of pragmatic claims concerning social organization. As a social commentator, he speaks of both practical and ideal forms of education and social organization. As a moralist, he continually attempts to unite the individual and the citizen through some form of universal political action or consent. In Discourse on the Origin and Foundation of Inequality Among Mankind 1755, Rousseau presents us with an almost idyllic view of humanity. In nature humans are first seen as little more than animals except for their special species sympathy. Later, through an explanation of the development of reason and language, he is able to suggest how humans, while retaining this sympathy, can, by distancing themselves from nature, understand their individual selves. This leads to natural community and the closest thing to what Rousseau considers humanity’s perfect moment. Private property quickly follows on the division of labor, and humans find themselves alienated from each other by the class divisions engendered by private property. Thus man, who was born in freedom, now finds himself in chains. The Social Contract or Principles of Political Right 1762 has a more ambitious goal. With an account of the practical role of the legislator and the introduction of the concept of the general will, Rousseau attempts to give us a foundation for good government by presenting a solution to the conflicts between the particular and the universal, the individual and the citizen, and the actual and the moral. Individuals, freely agreeing to a social pact and giving up their rights to the community, are assured of the liberties and equality of political citizenship found in the contract. It is only through being a citizen that the individual can fully realize his freedom and exercise his moral rights and duties. While the individual is naturally good, he must always guard against being dominated or dominating. Rousseau finds a solution to the problems of individual freedoms and interests in a superior form of moral/political action that he calls the general will. The individual as citizen substitutes “I must” for “I will,” which is also an “I shall” when it expresses assent to the general will. The general will is a universal force or statement and thus is more noble than any particular will. In willing his own interest, the citizen is at the same time willing what is communally good. The particular and the universal are united. The individual human participant realizes himself in realizing the good of all. As a practical political commentator Rousseau knew that the universal and the particular do not always coincide. For this he introduced the idea of the legislator, which allows the individual citizen to realize his fulfillment as social being and to exercise his individual rights through universal consent. In moments of difference between the majority will and the general will the legislator will instill the correct moral/political understanding. This will be represented in the laws. While sovereignty rests with the citizens, Rousseau does not require that political action be direct. Although all government should be democratic, various forms of government from representative democracy preferable in small societies to strong monarchies preferable in large nation-states may be acceptable. To shore up the unity and stability of individual societies, Rousseau suggests a sort of civic religion to which all citizens subscribe and in which all members Rousseau, Jean-Jacques Rousseau, Jean-Jacques 800    800 participate. His earlier writings on education and his later practical treatises on the governments of Poland and Corsica reflect related concerns with natural and moral development and with historical and geographical considerations. 

Royce, Josiah 18551916, American philosopher best known for his pragmatic idealism, his ethics of loyalty, and his theory of community. Educated at Berkeley, at Johns Hopkins, and in Germany, he taught philosophy at Harvard from 1882. Royce held that a concept of the absolute or eternal was needed to account for truth, ultimate meaning, and reality in the face of very real evil in human experience. Seeking to reconcile individuals with the Absolute, he postulated, in The World and the Individual 1899,1901, Absolute Will and Thought as an expression of the concrete and differentiated individuality of the world. Royce saw the individual self as both moral and sinful, developing through social interaction, community experience, and communal and self-interpretation. Self is constituted by a life plan, by loyalty to an ultimate goal. Yet selflimitation and egoism, two human sins, work against achievement of individual goals, perhaps rendering life a senseless failure. The self needs saving and this is the message of religion, argues Royce The Religious Aspects of Philosophy, 1885; The Sources of Religious Insight, 1912. For Royce, the instrument of salvation is the community. In The Philosophy of Loyalty 1908, he develops an ethics of loyalty to loyalty, i.e., the extension of loyalty throughout the human community. In The Problem of Christianity 1913, Royce presents a doctrine of community that overcomes the individualismcollectivism dilemma and allows a genuine blending of individual and social will. Community is built through interpretation, a mediative process that reconciles two ideas, goals, and persons, bringing common meaning and understanding. Interpretation involves respect for selves as dynamos of ideas and purposes, the will to interpret, dissatisfaction with partial meanings and narrowness of view, reciprocity, and mutuality. In this work, the Absolute is a “Community of Interpretation and Hope,” in which there is an endlessly accumulating series of interpretations and significant deeds. An individual contribution thus is not lost but becomes an indispensable element in the divine life. Among Royce’s influential students were C. I. Lewis, William Ernest Hocking, Norbert Wiener, Santayana, and T. S. Eliot.

rule of law, the largely formal or procedural properties of a well-ordered legal system. Commonly, these properties are thought to include: a prohibition of arbitrary power the lawgiver is also subject to the laws; laws that are general, prospective, clear, and consistent capable of guiding conduct; and tribunals courts that are reasonably accessible and fairly structured to hear and determine legal claims. Contemporary discussions of the rule of law focus on two major questions: 1 to what extent is conformity to the rule of law essential to the very idea of a legal system; and 2 what is the connection between the rule of law and the substantive moral value of a legal system? 

Russell, Bertrand Arthur William 18721970, British philosopher, logician, social reformer, and man of letters, one of the founders of analytic philosophy. Born into an aristocratic political family, Russell always divided his interests between politics and philosophy. Orphaned at four, he was brought up by his grandmother, Royce, Josiah Russell, Bertrand Arthur William 801    801 who educated him at home with the help of tutors. He studied mathematics at Cambridge from 1890 to 1893, when he turned to philosophy. At home he had absorbed J. S. Mill’s liberalism, but not his empiricism. At Cambridge he came under the influence of neo-Hegelianism, especially the idealism of McTaggart, Ward his tutor, and Bradley. His earliest logical views were influenced most by Bradley, especially Bradley’s rejection of psychologism. But, like Ward and McTaggart, he rejected Bradley’s metaphysical monism in favor of pluralism or monadism. Even as an idealist, he held that scientific knowledge was the best available and that philosophy should be built around it. Through many subsequent changes, this belief about science, his pluralism, and his anti-psychologism remained constant. In 1895, he conceived the idea of an idealist encyclopedia of the sciences to be developed by the use of transcendental arguments to establish the conditions under which the special sciences are possible. Russell’s first philosophical book, An Essay on the Foundations of Geometry 1897, was part of this project, as were other mostly unfinished and unpublished pieces on physics and arithmetic written at this time see his Collected Papers, vols. 12. Russell claimed, in contrast to Kant, to use transcendental arguments in a purely logical way compatible with his anti-psychologism. In this case, however, it should be both possible and preferable to replace them by purely deductive arguments. Another problem arose in connection with asymmetrical relations, which led to contradictions if treated as internal relations, but which were essential for any treatment of mathematics. Russell resolved both problems in 1898 by abandoning idealism including internal relations and his Kantian methodology. He called this the one real revolution in his philosophy. With his Cambridge contemporary Moore, he adopted an extreme Platonic realism, fully stated in The Principles of Mathematics 1903 though anticipated in A Critical Exposition of the Philosophy of Leibniz 1900. Russell’s work on the sciences was by then concentrated on pure mathematics, but the new philosophy yielded little progress until, in 1900, he discovered Peano’s symbolic logic, which offered hope that pure mathematics could be treated without Kantian intuitions or transcendental arguments. On this basis Russell propounded logicism, the claim that the whole of pure mathematics could be derived deductively from logical principles, a position he came to independently of Frege, who held a similar but more restricted view but whose work Russell discovered only later. Logicism was announced in The Principles of Mathematics; its development occupied Russell, in collaboration with Whitehead, for the next ten years. Their results were published in Principia Mathematica 191013, 3 vols., in which detailed derivations were given for Cantor’s set theory, finite and transfinite arithmetic, and elementary parts of measure theory. As a demonstration of Russell’s logicism, Principia depends upon much prior arithmetization of mathematics, e.g. of analysis, which is not explicitly treated. Even with these allowances much is still left out: e.g., abstract algebra and statistics. Russell’s unpublished papers Papers, vols. 45, however, contain logical innovations not included in Principia, e.g., anticipations of Church’s lambda-calculus. On Russell’s extreme realism, everything that can be referred to is a term that has being though not necessarily existence. The combination of terms by means of a relation results in a complex term, which is a proposition. Terms are neither linguistic nor psychological. The first task of philosophy is the theoretical analysis of propositions into their constituents. The propositions of logic are unique in that they remain true when any of their terms apart from logical constants are replaced by any other terms. In 1901 Russell discovered that this position fell prey to self-referential paradoxes. For example, if the combination of any number of terms is a new term, the combination of all terms is a term distinct from any term. The most famous such paradox is called Russell’s paradox. Russell’s solution was the theory of types, which banned self-reference by stratifying terms and expressions into complex hierarchies of disjoint subclasses. The expression ‘all terms’, e.g., is then meaningless unless restricted to terms of specified types, and the combination of terms of a given type is a term of different type. A simple version of the theory appeared in Principles of Mathematics appendix A, but did not eliminate all the paradoxes. Russell developed a more elaborate version that did, in “Mathematical Logic as Based on the Theory of Types” 1908 and in Principia. From 1903 to 1908 Russell sought to preserve his earlier account of logic by finding other ways to avoid the paradoxes  including a well-developed substitutional theory of classes and relations posthumously published in Essays in Analysis, 1974, and Papers, vol. 5. Other costs of type theory for Russell’s logicism included the vastly increased complexity of the resulting sysRussell, Bertrand Arthur William Russell, Bertrand Arthur William 802    802 tem and the admission of the problematic axiom of reducibility. Two other difficulties with Russell’s extreme realism had important consequences: 1 ‘I met Quine’ and ‘I met a man’ are different propositions, even when Quine is the man I met. In the Principles, the first proposition contains a man, while the second contains a denoting concept that denotes the man. Denoting concepts are like Fregean senses; they are meanings and have denotations. When one occurs in a proposition the proposition is not about the concept but its denotation. This theory requires that there be some way in which a denoting concept, rather than its denotation, can be denoted. After much effort, Russell concluded in “On Denoting” 1905 that this was impossible and eliminated denoting concepts as intermediaries between denoting phrases and their denotations by means of his theory of descriptions. Using firstorder predicate logic, Russell showed in a broad, though not comprehensive range of cases how denoting phrases could be eliminated in favor of predicates and quantified variables, for which logically proper names could be substituted. These were names of objects of acquaintance  represented in ordinary language by ‘this’ and ‘that’. Most names, he thought, were disguised definite descriptions. Similar techniques were applied elsewhere to other kinds of expression e.g. class names resulting in the more general theory of incomplete symbols. One important consequence of this was that the ontological commitments of a theory could be reduced by reformulating the theory to remove expressions that apparently denoted problematic entities. 2 The theory of incomplete symbols also helped solve extreme realism’s epistemic problems, namely how to account for knowledge of terms that do not exist, and for the distinction between true and false propositions. First, the theory explained how knowledge of a wide range of items could be achieved by knowledge by acquaintance of a much narrower range. Second, propositional expressions were treated as incomplete symbols and eliminated in favor of their constituents and a propositional attitude by Russell’s multiple relation theory of judgment. These innovations marked the end of Russell’s extreme realism, though he remained a Platonist in that he included universals among the objects of acquaintance. Russell referred to all his philosophy after 1898 as logical atomism, indicating thereby that certain categories of items were taken as basic and items in other categories were constructed from them by rigorous logical means. It depends therefore upon reduction, which became a key concept in early analytic philosophy. Logical atomism changed as Russell’s logic developed and as more philosophical consequences were drawn from its application, but the label is now most often applied to the modified realism Russell held from 1905 to 1919. Logic was central to Russell’s philosophy from 1900 onward, and much of his fertility and importance as a philosopher came from his application of the new logic to old problems. In 1910 Russell became a lecturer at Cambridge. There his interests turned to epistemology. In writing a popular book, Problems of Philosophy 1912, he first came to appreciate the work of the British empiricists, especially Hume and Berkeley. He held that empirical knowledge is based on direct acquaintance with sense-data, and that matter itself, of which we have only knowledge by description, is postulated as the best explanation of sense-data. He soon became dissatisfied with this idea and proposed instead that matter be logically constructed out of sensedata and unsensed sensibilia, thereby obviating dubious inferences to material objects as the causes of sensations. This proposal was inspired by the successful constructions of mathematical concepts in Principia. He planned a large work, “Theory of Knowledge,” which was to use the multiple relation theory to extend his account from acquaintance to belief and inference Papers, vol. 7. However, the project was abandoned as incomplete in the face of Wittgenstein’s attacks on the multiple relation theory, and Russell published only those portions dealing with acquaintance. The construction of matter, however, went ahead, at least in outline, in Our Knowledge of the External World 1914, though the only detailed constructions were undertaken later by Carnap. On Russell’s account, material objects are those series of sensibilia that obey the laws of physics. Sensibilia of which a mind is aware sense-data provide the experiential basis for that mind’s knowledge of the physical world. This theory is similar, though not identical, to phenomenalism. Russell saw the theory as an application of Ockham’s razor, by which postulated entities were replaced by logical constructions. He devoted much time to understanding modern physics, including relativity and quantum theory, and in The Analysis of Matter 1927 he incorporated the fundamental ideas of those theories into his construction of the physical world. In this book he abandoned sensibilia as fundamental constituents of the world in favor Russell, Bertrand Arthur William Russell, Bertrand Arthur William 803    803 of events, which were “neutral” because intrinsically neither physical nor mental. In 1916 Russell was dismissed from Cambridge on political grounds and from that time on had to earn his living by writing and public lecturing. His popular lectures, “The Philosophy of Logical Atomism” 1918, were a result of this. These lectures form an interim work, looking back on the logical achievements of 190510 and emphasizing their importance for philosophy, while taking stock of the problems raised by Wittgenstein’s criticisms of the multiple relation theory. In 1919 Russell’s philosophy of mind underwent substantial changes, partly in response to those criticisms. The changes appeared in “On Propositions: What They Are and How They Mean” 1919 and The Analysis of Mind 1921, where the influence of contemporary trends in psychology, especially behaviorism, is evident. Russell gave up the view that minds are among the fundamental constituents of the world, and adopted neutral monism, already advocated by Mach, James, and the American New Realists. On Russell’s neutral monism, a mind is constituted by a set of events related by subjective temporal relations simultaneity, successiveness and by certain special “mnemic” causal laws. In this way he was able to explain the apparent fact that “Hume’s inability to perceive himself was not peculiar.” In place of the multiple relation theory Russell identified the contents of beliefs with images “imagepropositions” and words “word-propositions”, understood as certain sorts of events, and analyzed truth qua correspondence in terms of resemblance and causal relations. From 1938 to 1944 Russell lived in the United States, where he wrote An Inquiry into Meaning and Truth 1940 and his popular A History of Western Philosophy 1945. His philosophical attention turned from metaphysics to epistemology and he continued to work in this field after he returned in 1944 to Cambridge, where he completed his last major philosophical work, Human Knowledge: Its Scope and Limits 1948. The framework of Russell’s early epistemology consisted of an analysis of knowledge in terms of justified true belief though it has been suggested that he unintentionally anticipated Edmund Gettier’s objection to this analysis, and an analysis of epistemic justification that combined fallibilism with a weak empiricism and with a foundationalism that made room for coherence. This framework was retained in An Inquiry and Human Knowledge, but there were two sorts of changes that attenuated the foundationalist and empiricist elements and accentuated the fallibilist element. First, the scope of human knowledge was reduced. Russell had already replaced his earlier Moorean consequentialism about values with subjectivism. Contrast “The Elements of Ethics,” 1910, with, e.g., Religion and Science, 1935, or Human Society in Ethics and Politics, 1954. Consequently, what had been construed as self-evident judgments of intrinsic value came to be regarded as non-cognitive expressions of desire. In addition, Russell now reversed his earlier belief that deductive inference can yield new knowledge. Second, the degree of justification attainable in human knowledge was reduced at all levels. Regarding the foundation of perceptual beliefs, Russell came to admit that the object-knowledge “acquaintance with a sensedatum” was replaced by “noticing a perceptive occurrence” in An Inquiry that provides the non-inferential justification for a perceptual belief is buried under layers of “interpretation” and unconscious inference in even the earliest stages of perceptual processes. Regarding the superstructure of inferentially justified beliefs, Russell concluded in Human Knowledge that unrestricted induction is not generally truthpreserving anticipating Goodman’s “new riddle of induction”. Consideration of the work of Reichenbach and Keynes on probability led him to the conclusion that certain “postulates” are needed “to provide the antecedent probabilities required to justify inductions,” and that the only possible justification for believing these postulates lies, not in their self-evidence, but in the resultant increase in the overall coherence of one’s total belief system. In the end, Russell’s desire for certainty went unsatisfied, as he felt himself forced to the conclusion that “all human knowledge is uncertain, inexact, and partial. To this doctrine we have not found any limitation whatever.” Russell’s strictly philosophical writings of 1919 and later have generally been less influential than his earlier writings. His influence was eclipsed by that of logical positivism and ordinary language philosophy. He approved of the logical positivists’ respect for logic and science, though he disagreed with their metaphysical agnosticism. But his dislike of ordinary language philosophy was visceral. In My Philosophical Development 1959, he accused its practitioners of abandoning the attempt to understand the world, “that grave and important task which philosophy throughout the ages has hitherto pursued.” 

Russian nihilism, a form of nihilism, a phenomenon mainly of Russia in the 1860s, which, in contrast to the general cultural nihilism that Nietzsche later criticized in the 1880s as a “dead-end” devaluing of all values, was futureoriented and “instrumental,” exalting possibility over actuality. Russian nihilists urged the “annihilation”  figurative and literal  of the past and present, i.e., of realized social and cultural values and of such values in process of realization, in the name of the future, i.e., for the sake of social and cultural values yet to be realized. Bakunin, as early as 1842, had stated the basic nihilist theme: “the negation of what exists . . . for the benefit of the future which does not yet exist.” The bestknown literary exemplar of nihilism in Russia is the character Bazarov in Turgenev’s novel Fathers and Sons 1862. Its most articulate spokesman was Dmitri Pisarev 184068, who shared Bazarov’s cultural anti-Romanticism, philosophical anti-idealism, and unquestioned trust in the power of natural science to solve social and moral problems. Pisarev proclaimed, “It is precisely in the [spread-eagled, laboratory] frog that the salvation . . . of the Russian people is to be found.” And he formulated what may serve as the manifesto of Russian nihilism: “What can be broken should be broken; what will stand the blow is fit to live; what breaks into smithereens is rubbish; in any case, strike right and left, it will not and cannot do any harm.” 

Russian philosophy, the philosophy produced by Russian thinkers, both in Russia and in the countries to which they emigrated, from the mideighteenth century to the present. There was no Renaissance in Russia, but in the early eighteenth century Peter the Great, in opening a “window to the West,” opened Russia up to Western philosophical influences. The beginnings of Russian speculation date from that period, in the dialogues, fables, and poems of the anti-Enlightenment thinker Gregory Skovoroda 172294 and in the social tracts, metaphysical treatises, and poems of the Enlightenment thinker Alexander Radishchev 17491802. Until the last quarter of the nineteenth century the most original and forceful Russian thinkers stood outside the academy. Since then, both in Russia and in Western exile, a number of the most important Russian philosophers  including Berdyaev and Lev Shestov 1866 1938  have been  professors. The nineteenth-century thinkers, though educated, lacked advanced degrees. The only  professor among them, Peter Lavrov 18231900, taught mathematics and science rather than philosophy during the 1850s. If we compare Russian philosophy to German philosophy of this period, with its galaxy of  professors  Wolff, Kant, Fichte, Schelling, Hegel, Dilthey  the contrast is sharp. However, if we compare Russian philosophy to English or French philosophy, the contrast fades. No professors of philosophy appear in the line from Francis Bacon through Hobbes, Locke, Berkeley, Hume, Bentham, and J. S. Mill, to Spencer. And in France Montaigne, Descartes, Pascal, Rousseau, and Comte were all non-professors. True to their non-professional, even “amateur” status, Russian philosophers until the late nineteenth century paid little attention to the more technical disciplines: logic, epistemology, philosophy of language, and philosophy of science. They focused instead on philosophical anthropology, ethics, social and political philosophy, philosophy of history, and philosophy of religion. In Russia, more than in any other Western cultural tradition, speculation, fiction, and poetry have been linked. On the one hand, major novelists such as Tolstoy and Dostoevsky, and major poets such as Pasternak and Brodsky, have engaged in wide-ranging philosophical reflection. On the other hand, philosophers such as Skovoroda, Alexei Khomyakov 180460, and Vladimir Solovyov 18531900 were gifted poets, while thinkers such as Herzen, Konstantin Leontyev 183191, and the anti-Leninist Marxist Alexander Bogdanov 18731928 made their literary mark with novels, short stories, and memoirs. Such Russian thinkers as Vasily Rozanov 18561919 and Shestov, although they wrote no belles lettres, were celebrated in literary circles for their sparkling essayistic and aphoristic styles. Certain preoccupations of nineteenth-century Russian thinkers  especially Pyotr Chaadaev 17941856 during the 1820s and 1830s, the Slavophiles and Westernizers during the 1840s and 1850s, and the Populists during the 1860s and 1870s  might appear to be distinctive but in fact were not. The controversial questions of Russia’s relation to Western Europe and of Russell’s paradox Russian philosophy 805    805 Russia’s “special path” to modernity have their counterparts in the reflections of thinkers in Spain “Spain and Europe”, Germany the Sonderweg  a term of which the Russian osobyi put’ is a translation, and Poland “the Polish Question”. The content of Russian philosophy may be characterized in general terms as tending toward utopianism, maximalism, moralism, and soteriology. To take the last point first: Hegelianism was received in Russia in the 1830s not only as an allembracing philosophical system but also as a vehicle of secular salvation. In the 1860s Darwinism was similarly received, as was Marxism in the 1890s. Utopianism appears at the historical and sociopolitical level in two of Solovyov’s characteristic doctrines: his early “free theocracy,” in which the spiritual authority of the Roman pope was to be united with the secular authority of the Russian tsar; and his later ecumenical project of reuniting the Eastern Russian Orthodox and Western Roman Catholic churches in a single “universal [vselenskaia] church” that would also incorporate the “Protestant principle” of free philosophical and theological inquiry. Maximalism appears at the individual and religious level in Shestov’s claim that God, for whom alone “all things are possible,” can cause what has happened not to have happened and, in particular, can restore irrecoverable human loss, such as that associated with disease, deformity, madness, and death. Maximalism and moralism are united at the cosmic and “scientific-technological” level in Nikolai Fyodorov’s 18291903 insistence on the overriding moral obligation of all men “the sons” to join the common cause of restoring life to “the fathers,” those who gave them life rather than, as sanctioned by the “theory of progress,” pushing them, figuratively if not literally, into the grave. Certain doctrinal emphases and assumptions link Russian thinkers from widely separated points on the political and ideological spectrum: 1 Russian philosophers were nearly unanimous in dismissing the notorious CartesianHumean “problem of other minds” as a nonproblem. Their convictions about human community and conciliarity sobornost’, whether religious or secular, were too powerful to permit Russian thinkers to raise serious doubts as to whether their moaning and bleeding neighbor was “really” in pain. 2 Most Russian thinkers  the Westernizers were a partial exception  viewed key Western philosophical positions and formulations, from the Socratic “know thyself” to the Cartesian cogito, as overly individualistic and overly intellectualistic, as failing to take into account the wholeness of the human person. 3 Both such anti-Marxists as Herzen with his “philosophy of the act” and Fyodorov with his “projective” common task and the early Russian Marxists were in agreement about the unacceptability of the “Western” dichotomy between thought and action. But when they stressed the unity of theory and practice, a key question remained: Who is to shape this unity? And what is its form? The threadbare MarxistLeninist “philosophy” of the Stalin years paid lip service to the freedom involved in forging such a unity. Stalin in fact imposed crushing restraints upon both thought and action. Since 1982, works by and about the previously abused or neglected religious and speculative thinkers of Russia’s past have been widely republished and eagerly discussed. This applies to Fyodorov, Solovyov, Leontyev, Rozanov, Berdyaev, Shestov, and the Husserlian Shpet, among others. 

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Ryle, Gilbert 190076, English analytic philosopher known especially for his contributions to the philosophy of mind and his attacks on Cartesianism. His best-known work is the masterpiece The Concept of Mind 1949, an attack on what he calls “Cartesian dualism” and a defense of a type of logical behaviorism. This dualism he dubs “the dogma of the Ghost in the Machine,” the Machine being the body, which is physical and publicly observable, and the Ghost being the mind conceived as a private or secret arena in which episodes of sense perception, consciousness, and inner perception take place. A person, then, is a combination of such a mind and a body, with the mind operating the body through exercises of will called “volitions.” Ryle’s attack on this doctrine is both sharply focused and multifarious. He finds that it rests on a category mistake, namely, assimilating statements about mental processes to the same category as statements about physical processes. This is a mistake in the logic of mental statements and mental concepts and leads to the mistaken metaphysical theory that a person is composed of two separate and distinct though somehow related entities, a mind and a body. It is true that statements about the physical are statements about things and their changes. But statements about the mental Ryle, Gilbert Ryle, Gilbert 806    806 are not, and in particular are not about a thing called “the mind.” These two types of statements do not belong to the same category. To show this, Ryle deploys a variety of arguments, including arguments alleging the impossibility of causal relations between mind and body and arguments alleging vicious infinite regresses. To develop his positive view on the nature of mind, Ryle studies the uses and hence the logic of mental terms and finds that mental statements tell us that the person performs observable actions in certain ways and has a disposition to perform other observable actions in specifiable circumstances. For example, to do something intelligently is to do something physical in a certain way and to adjust one’s behavior to the circumstances, not, as the dogma of the Ghost in the Machine would have it, to perform two actions, one of which is a mental action of thinking that eventually causes a separate physical action. Ryle buttresses this position with many acute and subtle analyses of the uses of mental terms. Much of Ryle’s other work concerns philosophical methodology, sustaining the thesis which is the backbone of The Concept of Mind that philosophical problems and doctrines often arise from conceptual confusion, i.e., from mistakes about the logic of language. Important writings in this vein include the influential article “Systematically Misleading Expressions” and the book Dilemmas 1954. Ryle was also interested in Grecian philosophy throughout his life, and his last major work, Plato’s Progress, puts forward novel hypotheses about changes in Plato’s views, the role of the Academy, the purposes and uses of Plato’s dialogues, and Plato’s relations with the rulers of Syracuse. 

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Saadiah Gaon 882942, Jewish exegete, philosopher, liturgist, grammarian, and lexicographer. Born in the Fayyum in Egypt, Saadiah wrote his first Hebrew dictionary by age twenty. He removed to Tiberias, probably fleeing the backlash of his polemic against the Karaite biblicist, anti-Talmudic sect. There he mastered the inductive techniques of semantic analysis pioneered by Muslim MuÅtazilites in defending their rationalistic monotheism and voluntaristic theodicy. He learned philologically from the Masoretes and liturgical poets, and philosophically from the MuÅtazilite-influenced Jewish metaphysician Daud al-Muqammif of Raqqa in Iraq, and Isaac Israeli of Qayrawan in Tunisia, a Neoplatonizing physician, with whom the young philosopher attempted a correspondence. But his sense of system, evidenced in his pioneering chronology, prayerbook, and scheme of tropes, and nurtured by Arabic versions of Plato but seemingly not much Aristotle, allowed him to outgrow and outshine his mentors. He came to prominence by successfully defending the traditional Hebrew calendar, using astronomical, mathematical, and rabbinic arguments. Called to Baghdad, he became Gaon Hebrew, ‘Eminence’ or head of the ancient Talmudic academy of Pumpedita, then nearly defunct. His commentaries on rabbinic property law and his letters to Jewish communities as far away as Spain refurbished the authority of the academy, but a controversy with the Exilarch, secular head of Mesopotamian Jewry, led to his deposition and six years in limbo, deprived of his judicial authority. He delved into scientific cosmology, translated many biblical books into Arabic with philosophic commentaries and thematic introductions, and around 933 completed The Book of Critically Chosen Beliefs and Convictions, the first Jewish philosophical summa. Unusual among medieval works for a lengthy epistemological introduction, its ten Arabic treatises defend and define creation, monotheism, human obligation and virtue, theodicy, natural retribution, resurrection, immortality and recompense, Israel’s redemption, and the good life. Saadiah argues that no single good suffices for human happiness; each in isolation is destructive. The Torah prepares the optimal blend of the appetitive and erotic, procreative, civilizational, ascetic, political, intellectual, pious, and tranquil. Following al-Rhazi d. 925 or 932, Saadiah argues that since destruction always overcomes organization in this world, sufferings will always outweigh pleasures; therefore as in rabbinic and MuÅtazilite theodicy God must be assumed to right the balances in the hereafter. Indeed, justice is the object of creation  not simply that the righteous be rewarded but that all should earn their deserved requital: the very light that is sown for the righteous is the fire that torments the wicked. But if requital and even recompense must be earned, this life is much more than an anteroom. Authenticity becomes a value in itself: the innocent are not told directly that their sufferings are a trial, or their testing would be invalid. Only by enduring their sufferings without interference can they demonstrate the qualities that make them worthy of the highest reward. Movingly reconciled with the Exilarch, Saadiah ended his life as Gaon. His voluntarism, naturalism, and rationalism laid philosophical foundations for Maimonides, and his inductive exegesis became a cornerstone of critical hermeneutics. 

Saint Petersburg paradox, a puzzle about gambling that motivated the distinction between expected return and expected utility. Daniel Bernoulli published it in a St. Petersburg journal in 1738. It concerns a gamble like this: it pays $2 if heads appears on the first toss of a coin, $4 if heads does not appear until the second toss, $8 if heads does not appear until the third toss, and so on. The expected return from the gamble is ½2 ! ¼4 ! 1 /88 ! . . . , or 1 ! 1 ! 1 ! ..., i.e., it is infinite. But no one would pay much for the gamble. So it seems that expected returns do not govern rational preferences. Bernoulli argued that expected utilities govern rational preferences. He also held that the utility of wealth is proportional to the log of the amount of wealth. Given his assumptions, the gamble has finite 808 S    808 expected utility, and should not be preferred to large sums of money. However, a twentieth-century version of the paradox, attributed to Karl Menger, reconstructs the gamble, putting utility payoffs in place of monetary payoffs, so that the new gamble has infinite expected utility. Since no one would trade much utility for the new gamble, it also seems that expected utilities do not govern rational preferences. The resolution of the paradox is under debate. 

Saint-Simon, Comte de, title of Claude-Henri de Rouvroy 17601825, French social reformer. An aristocrat by birth, he initially joined the ranks of the enlightened and liberal bourgeoisie. His Newtonian Letters to an Inhabitant of Geneva 1803 and Introduction to Scientific Works of the Nineteenth Century 1808 championed Condorcet’s vision of scientific and technological progress. With Auguste Comte, he shared a positivistic philosophy of history: the triumph of science over metaphysics. Written in wartime, The Reorganization of European Society 1814 urged the creation of a European parliamentary system to secure peace and unity. Having moved from scientism to pacifism, Saint-Simon moved further to industrialism. In 1817, under the influence of two theocratic thinkers, de Maistre and Bonald, Saint-Simon turned away from classical economic liberalism and repudiated laissez-faire capitalism. The Industrial System 1820 drafts the program for a hierarchical state, a technocratic society, and a planned economy. The industrial society of the future is based on the principles of productivity and cooperation and led by a rational and efficient class, the industrialists artists, scientists, and technicians. He argued that the association of positivism with unselfishness, of techniques of rational production with social solidarity and interdependency, would remedy the plight of the poor. Industrialism prefigures socialism, and socialism paves the way for the rule of the law of love, the eschatological age of The New Christianity 1825. This utopian treatise, which reveals Saint-Simon’s alternative to reactionary Catholicism and Protestant individualism, became the Bible of the Saint-Simonians, a sectarian school of utopian socialists.

Sakti, in Hindu thought, force, power, or energy, personified as the divine consort of the god Siva. Sakti is viewed as the feminine active divine aspect as contrasted with the masculine passive divine aspect, which affects the creation, maintenance, and dissolution of the universe, and possesses intelligence, will, knowledge, and action as modes.

samadhi, Sanskrit term meaning ‘concentration’, ‘absorption’, ‘superconscious state’, ‘altered state of consciousness’. In India’s philosophical tradition this term was made famous by its use in the Yoga system of Patañjali second century B.C.. In this system the goal was to attain the self’s freedom, so that the self, conceived as pure consciousness in its true nature, would not be limited by the material modes of existence. It was believed that through a series of yogic techniques the self is freed from its karmic fetters and liberated to its original state of self-luminous consciousness, known as samadhi. The Indian philosophical systems had raised and debated many epistemological and metaphysical questions regarding the nature of consciousness, the concept of mind, and the idea of the self. They also wondered whether a yogi who has attained samadhi is within the confines of the conventional moral realm. This issue is similar to Nietzsche’s idea of the transvaluation of values.  NIETZSCHE. D.K.C. samanantara-pratyaya, in Buddhism, a causal term meaning ‘immediately antecedent anantara and similar sama condition’. According to Buddhist causal theory, every existent is a continuum of momentary events of various kinds. These momentary events may be causally connected to one another in a variety of ways; one of these is denoted by the term samanantarapratyaya. This kind of causal connection requires that every momentary event have, as a necessary condition for its existence, an immediately preceding event of the same kind. So, e.g., among the necessary conditions for the occurrence of a moment of sensation in some continuum must be the occurrence of an immediately preceding moment of sensation in that same continuum. P.J.G. samatha, in Buddhism, tranquillity or calm. The term is used to describe both one kind of meditational practice and the states of consciousness produced by it. To cultivate tranquillity or calmness is to reduce the mind’s level of affect and, Saint-Simon samatha 809    809 finally, to produce a state of consciousness in which emotion is altogether absent. This condition is taken to have salvific significance because emotional disturbance of all kinds is thought to hinder clear perception and understanding of the way things are; reduction of affect therefore aids accurate cognition. The techniques designed to foster this reduction are essentially concentrative. 

samsara Sanskrit, ‘going around’, in Hindu thought, the ceaseless rounds of rebirth that constitute the human predicament. Samsara speaks of the relentless cycle of coming and going in transmigration of the soul from body to body in this and other worlds. It is the manifestation of karma, for one’s deeds bear fruition in the timing, status, form, and nature of the phenomenal person in future lives. Ordinary individuals have little prospect of release and in some systems the relationship among karma, rebirth, and samsara is a highly mechanical cosmic law of debt and credit which affirms that human deeds produce their own reward or punishment. For theists the Deity is the ultimate controller of samsara and can break the cycle, adjust it, or, by the god’s kindness or grace, save one from future births regardless of one’s actions. 

Sanches, Francisco c.15511623, Portugueseborn philosopher and physician. Raised in southern France, he took his medical degree at the  of Montpellier. After a decade of medical practice he was professor of philosophy at the  of Toulouse and later professor of medicine there. His most important work, Quod nihil sciturThat Nothing Is Known, 1581, is a classic of skeptical argumentation. Written at the same time that his cousin, Montaigne, wrote the “Apology for Raimund Sebond,” it devastatingly criticized the Aristotelian theory of knowledge. He began by declaring that he did not even know if he knew nothing. Then he examined the Aristotelian view that science consists of certain knowledge gained by demonstrations from true definitions. First of all, we do not possess such definitions, since all our definitions are just arbitrary names of things. The Aristotelian theory of demonstration is useless, since in syllogistic reasoning the conclusion has to be part of the evidence for the premises. E.g., how can one know that all men are mortal unless one knows that Socrates is mortal? Also, anything can be proven by syllogistic reasoning if one chooses the right premises. This does not produce real knowledge. Further we cannot know anything through its causes, since one would have to know the causes of the causes, and the causes of these, ad infinitum. Sanches also attacked the Platonic theory of knowledge, since mathematical knowledge is about ideal rather than real objects. Mathematics is only hypothetical. Its relevance to experience is not known. True science would consist of perfect knowledge of a thing. Each particular would be understood in and by itself. Such knowledge can be attained only by God. We cannot study objects one by one, since they are all interrelated and interconnected. Our faculties are also not reliable enough. Hence genuine knowledge cannot be attained by humans. What we can do, using “scientific method” a term first used by Sanches, is gather careful empirical information and make cautious judgments about it. His views were well known in the seventeenth century, and may have inspired the “mitigated skepticism” of Gassendi and others. 

sanction, anything whose function is to penalize or reward. It is useful to distinguish between social sanctions, legal sanctions, internal sanctions, and religious sanctions. Social sanctions are extralegal pressures exerted upon the agent by others. For example, others might distrust us, ostracize us, or even physically attack us, if we behave in certain ways. Legal sanctions include corporal punishment, imprisonment, fines, withdrawal of the legal rights to run a business or to leave the area, and other penalties. Internal sanctions may include not only guilt feelings but also the sympathetic pleasures of helping others or the gratified conscience of doing right. Divine sanctions, if there are any, are rewards or punishments given to us by a god while we are alive or after we die. There are important philosophical questions concerning sanctions. Should law be defined as the rules the breaking of which elicits punishment by the state? Could there be a moral duty to behave in a given way if there were no social sanctions concerning such behavior? If not, then a conventionalist account of moral duty seems unavoidable. And, to what extent does the combined effect of external and internal sanctions make rational egoism or prudence or self-interest coincide with morality?

Sankhya-Yoga, a system of Hindu thought that posits two sorts of reality, immaterial purusha and material prakrti. Prakrti, a physical stuff composed of what is lightweight and finegrained sattva, what is heavy and coarse tamas, and what is active rajas, is in some sense the source of matter, force, space, and time. Sankhya physical theory explains the complex by reference to the properties of its components. The physical universe everlastingly oscillates between states in which the three elements exist unmixed and states in which they mingle; when they mingle, they compose physical bodies some of which incarnate bits of purusha. When the basic elements mingle, transmigration occurs. Pursha is inherently passive, and mental properties belong only to the composite of prakrti and purusha, leading critics to ask what, when the physical elements are separated, individuates one mind from another. The answer is that one bit of purusha has one transmigratory history and another bit has another history. Critics e.g., Nyaya-Vaishesika philosophers were not satisfied with this answer, which allowed no intrinsic distinctions between bits of non-incarnate purusha. The dialectic of criticism led to Advaita Vedanta for which all purusha distinctions are illusory and other varieties of Vedanta Dvaita and Visistadvaita for which minds have inherent, not merely embodied, consciousness. Sankhya claims that there can be no emergent properties properties not somehow a reshuffling of prior properties, so the effect must in some sense preexist in the cause. 

Santayana, George, philosopher and writer. Born in Spain, he arrived in the United States as a child, received his education at Harvard, and rose to professor of philosophy there. He first came to prominence for his view, developed in The Sense of Beauty 1896, that beauty is objectified pleasure. His The Life of Reason 5 vols., 1905, a celebrated expression of his naturalistic vision, traces human creativity in ordinary life, society, art, religion, and science. He denied that his philosophy ever changed, but the mature expression of his thought, in Skepticism and Animal Faith 1923 and The Realms of Being 4 vols., 192740, is deliberately ontological and lacks the phenomenological emphasis of the earlier work. Human beings, according to Santayana, are animals in a material world contingent to the core. Reflection must take as its primary datum human action aimed at eating and fleeing. The philosophy of animal faith consists of disentangling the beliefs tacit in such actions and yields a realism concerning both the objects of immediate consciousness and the objects of belief. Knowledge is true belief rendered in symbolic terms. As symbolism, it constitutes the hauntingly beautiful worlds of the senses, poetry, and religion; as knowledge, it guides and is tested by successful action. Santayana had been taught by William James, and his insistence on the primacy of action suggests a close similarity to the views of Dewey. He is, nevertheless, not a pragmatist in any ordinary sense: he views nature as the fully formed arena of human activity and experience as a flow of isolated, private sentience in this alien world. His deepest sympathy is with Aristotle, though he agrees with Plato about the mind-independent existence of Forms and with Schopenhauer about the dimness of human prospects. His mature four-realm ontology turns on the distinction between essence and matter. Essences are forms of definiteness. They are infinite in number and encompass everything possible. Their eternity makes them causally inefficacious: as possibilities, they cannot accomplish their own actualization. Matter, a surd and formless force, generates the physical universe by selecting essences for embodiment. Truth is the realm of being created by the intersection of matter and form: it is the eternal record of essences that have been, are being, and will be given actuality in the history of the world. Spirit or consciousness cannot be reduced to the motions of the physical organism that give rise to it. It is constituted by a sequence of acts or intuitions whose objects are essences but whose time-spanning, synthetic nature renders them impotent. Organic selectivity is the source of values. Accordingly, the good of each organism is a function of its nature. Santayana simply accepts the fact that some of these goods are incommensurable and the tragic reality that they may be incompatible, as well. Under favorable circumstances, a life of reason or of maximal harmonized satisfactions is possible for a while. The finest achievement of human beings, however, is the spiritual life in which we overcome animal partiality and thus all valuation in order to enjoy the intuition of eternal essences. Santayana identifies such spirituality with the best that religion and sound philosophy can offer. It does not help us escape finitude and death, but enables us Sankara Santayana, George 811    811 in this short life to transcend care and to intuit the eternal. Santayana’s exquisite vision has gained him many admirers but few followers. His system is a self-consistent and sophisticated synthesis of elements, such as materialism and Platonism, that have hitherto been thought impossible to reconcile. His masterful writing makes his books instructive and pleasurable, even if many of his characteristic views engender resistance among philosophers. J.La. Sapir-Whorf hypothesis, broadly, the claim that one’s perception, thought, and behavior are influenced by one’s language. The hypothesis was named after Benjamin Lee Whorf 1897 1941 and his teacher Edward Sapir 1884 1939. We may discern different versions of this claim by distinguishing degrees of linguistic influence, the highest of which is complete and unalterable determination of the fundamental structures of perception, thought, and behavior. In the most radical form, the hypothesis says that one’s reality is constructed by one’s language and that differently structured languages give rise to different realities, which are incommensurable. 

Sartre, Jean-Paul 190580, French philosopher and writer, the leading advocate of existentialism during the years following World War II. The heart of his philosophy was the precious notion of freedom and its concomitant sense of personal responsibility. He insisted, in an interview a few years before his death, that he never ceased to believe that “in the end one is always responsible for what is made of one,” only a slight revision of his earlier, bolder slogan, “man makes himself.” To be sure, as a student of Hegel, Marx, Husserl, and Heidegger  and because of his own physical frailty and the tragedies of the war  Sartre had to be well aware of the many constraints and obstacles to human freedom, but as a Cartesian, he never deviated from Descartes’s classical portrait of human consciousness as free and distinct from the physical universe it inhabits. One is never free of one’s “situation,” Sartre tells us, though one is always free to deny “negate” that situation and to try to change it. To be human, to be conscious, is to be free to imagine, free to choose, and responsible for one’s lot in life. As a student, Sartre was fascinated by Husserl’s new philosophical method, phenomenology. His first essays were direct responses to Husserl and applications of the phenomenological method. His essay on The Imagination in 1936 established the groundwork for much of what was to follow: the celebration of our remarkable freedom to imagine the world other than it is and following Kant the way that this ability informs all of our experience. In The Transcendence of the Ego 1937 he reconsidered Husserl’s central idea of a “phenomenological reduction” the idea of examining the essential structures of consciousness as such and argued following Heidegger that one cannot examine consciousness without at the same time recognizing the reality of actual objects in the world. In other words, there can be no such “reduction.” In his novel Nausea 1938, Sartre made this point in a protracted example: his bored and often nauseated narrator confronts a gnarled chestnut tree in the park and recognizes with a visceral shock that its presence is simply given and utterly irreducible. In The Transcendence of the Ego Sartre also reconsiders the notion of the self, which Husserl and so many earlier philosophers had identified with consciousness. But the self, Sartre argues, is not “in” consciousness, much less identical to it. The self is out there “in the world, like the self of another.” In other words, the self is an ongoing project in the world with other people; it is not simply self-awareness or self-consciousness as such “I think, therefore I am”. This separation of self and consciousness and the rejection of the self as simply self-consciousness provide the framework for Sartre’s greatest philosophical treatise, L’être et le néant Being and Nothingness, 1943. Its structure is unabashedly Cartesian, consciousness “being-for-itself” or pour soi on the one side, the existence of mere things “being-in-itself” or en soi on the other. The phraseology comes from Hegel. But Sartre does not fall into the Cartesian trap of designating these two types of being as separate “substances.” Instead, Sartre describes consciousness as “nothing’  “not a thing” but an activity, “a wind blowing from nowhere toward the world.” Sartre often resorts to visceral metaphors when developing this theme e.g., “a worm coiled in the heart of being”, but much of what he is arguing is familiar to philosophical readers in the more metaphor-free work of Kant, who also warned against the follies “paralogisms” of understanding consciousness as itself a possible object of consciousness rather than as the activity of constituting the objects of consciousness. As the lens of a camera can never see itself  and in a mirror only sees a reflection of itself  conSapir-Whorf hypothesis Sartre, Jean-Paul 812    812 sciousness can never view itself as consciousness and is only aware of itself  “for itself”  through its experience of objects. Ontologically, one might think of “nothingness” as “no-thing-ness,” a much less outrageous suggestion than those that would make it an odd sort of a thing. It is through the nothingness of consciousness and its activities that negation comes into the world, our ability to imagine the world other than it is and the inescapable necessity of imagining ourselves other than we seem to be. And because consciousness is nothingness, it is not subject to the rules of causality. Central to the argument of L’être et le néant and Sartre’s insistence on the primacy of human freedom is his insistence that consciousness cannot be understood in causal terms. It is always self-determining and, as such, “it always is what it is not, and is not what it is”  a playful paradox that refers to the fact that we are always in the process of choosing. Consciousness is “nothing,” but the self is always on its way to being something. Throughout our lives we accumulate a body of facts that are true of us  our “facticity”  but during our lives we remain free to envision new possibilities, to reform ourselves and to reinterpret our facticity in the light of new projects and ambitions  our “transcendence.” This indeterminacy means that we can never be anything, and when we try to establish ourselves as something particular  whether a social role policeman, waiter or a certain character shy, intellectual, cowardly  we are in “bad faith.” Bad faith is erroneously viewing ourselves as something fixed and settled Sartre utterly rejects Freud and his theory of the unconscious determination of our personalities and behavior, but it is also bad faith to view oneself as a being of infinite possibilities and ignore the always restrictive facts and circumstances within which all choices must be made. On the one hand, we are always trying to define ourselves; on the other hand we are always free to break away from what we are, and always responsible for what we have made of ourselves. But there is no easy resolution or “balance” between facticity and freedom, rather a kind of dialectic or tension. The result is our frustrated desire to be God, to be both in-itself and for-itself. But this is not so much blasphemy as an expression of despair, a form of ontological original sin, the impossibility of being both free and what we want to be. Life for Sartre is yet more complicated. There is a third basic ontological category, on a par with the being-in-itself and being-for-itself and not derivative of them. He calls it “being-for-others.” To say that it is not derivative is to insist that our knowledge of others is not inferred, e.g. by some argument by analogy, from the behavior of others, and we ourselves are not wholly constituted by our self-determinations and the facts about us. Sartre gives us a brutal but familiar everyday example of our experience of being-for-others in what he calls “the look” le regard. Someone catches us “in the act” of doing something humiliating, and we find ourselves defining ourselves probably also resisting that definition in their terms. In his Saint Genet 1953, Sartre describes such a conversion of the ten-year-old Jean Genet into a thief. So, too, we tend to “catch” one another in the judgments we make and define one another in terms that are often unflattering. But these judgments become an essential and ineluctible ingredient in our sense of ourselves, and they too lead to conflicts indeed, conflicts so basic and so frustrating that in his play Huis clos No Exit, 1943 Sartre has one of his characters utter the famous line, “Hell is other people.” In his later works, notably his Critique of Dialectical Reason 195859, Sartre turned increasingly to politics and, in particular, toward a defense of Marxism on existentialist principles. This entailed rejecting materialist determinism, but it also required a new sense of solidarity or what Sartre had wistfully called, following Heidegger, Mitsein or “being with others”. Thus in his later work he struggled to find a way of overcoming the conflict and insularity or the rather “bourgeois” consciousness he had described in Being and Nothingness. Not surprisingly given his constant political activities he found it in revolutionary engagement. Consonant with his rejection of bourgeois selfhood, Sartre turned down the 1964 Nobel prize for literature. 

sat/chit/ananda, also saccidananda, three Sanskrit terms combined to refer to the Highest Reality as ‘existence, intelligence, bliss’. The later thinkers of Advaita Vedanta, such as Shankara, used the term to denote the Absolute, Brahman, a state of oneness of being, of pure consciousness and of absolute value or freedom. These are not to be taken as attributes or accidents that qualify Brahman but terms that express its essential nature as experienced by human beings. Sat being, existence is also satyam truth, affirming that Brahman is experienced as being itself, not a being over against another. Chit is pure consciousness, sat/chit/ananda sat/chit/ananda 813    813 consciousness without object, and ananda is the experience of unlimited freedom and universal potentiality as well as satisfaction and the bliss that transcends both all that is pleasurable in the world and release from the bondage of samsara. Hindu theists understand sat/chit/ananda as the qualities of the supreme god. 

satisfaction, an auxiliary semantic notion introduced by Tarski in order to give a recursive definition of truth for languages containing quantifiers. Intuitively, the satisfaction relation holds between formulas containing free variables such as ‘Buildingx & Tallx’ and objects or sequences of objects such as the Empire State Building if and only if the formula “holds of” or “applies to” the objects. Thus, ‘Buildingx & Tallx’, is satisfied by all and only tall buildings, and ‘-Tallx1 & Tallerx1, x2’ is satisfied by any pair of objects in which the first object corresponding to ‘x1’ is not tall, but nonetheless taller than the second corresponding to ‘x2’. Satisfaction is needed when defining truth for languages with sentences built from formulas containing free variables, because the notions of truth and falsity do not apply to these “open” formulas. Thus, we cannot characterize the truth of the sentences ‘Dx Buildingx & Tallx’ ‘Some building is tall’ in terms of the truth or falsity of the open formula ‘Buildingx & Tallx’, since the latter is neither true nor false. But note that the sentence is true if and only if the formula is satisfied by some object. Since we can give a recursive definition of the notion of satisfaction for possibly open formulas, this enables us to use this auxiliary notion in defining truth. 

satisfiable, having a common model, a structure in which all the sentences in the set are true; said of a set of sentences. In modern logic, satisfiability is the semantic analogue of the syntactic, proof-theoretic notion of consistency, the unprovability of any explicit contradiction. The completeness theorem for first-order logic, that all valid sentences are provable, can be formulated in terms of satisfiability: syntactic consistency implies satisfiability. This theorem does not necessarily hold for extensions of first-order logic. For any sound proof system for secondorder logic there will be an unsatisfiable set of sentences without there being a formal derivation of a contradiction from the set. This follows from Gödel’s incompleteness theorem. One of the central results of model theory for first-order logic concerns satisfiability: the compactness theorem, due to Gödel in 1936, says that if every finite subset of a set of sentences is satisfiable the set itself is satisfiable. It follows immediately from his completeness theorem for first-order logic, and gives a powerful method to prove the consistency of a set of sentences. 

satisfice, to choose or do the good enough rather than the most or the best. ‘Satisfice’, an obsolete variant of ‘satisfy’, has been adopted by economist Herbert Simon and others to designate nonoptimizing choice or action. According to some economists, limitations of time or information may make it impossible or inadvisable for an individual, firm, or state body to attempt to maximize pleasure, profits, market share, revenues, or some other desired result, and satisficing with respect to such results is then said to be rational, albeit less than ideally rational. Although many orthodox economists think that choice can and always should be conceived in maximizing or optimizing terms, satisficing models have been proposed in economics, evolutionary biology, and philosophy. Biologists have sometimes conceived evolutionary change as largely consisting of “good enough” or satisficing adaptations to environmental pressures rather than as proceeding through optimal adjustments to such pressures, but in philosophy, the most frequent recent use of the idea of satisficing has been in ethics and rational choice theory. Economists typically regard satisficing as acceptable only where there are unwanted constraints on decision making; but it is also possible to see satisficing as entirely acceptable in itself, and in the field of ethics, it has recently been argued that there may be nothing remiss about moral satisficing, e.g., giving a good amount to charity, but less than one could give. It is possible to formulate satisficing forms of utilitarianism on which actions are morally right even if they contribute merely positively and/or in some large way, rather than maximally, to overall net human happiness. Bentham’s original formulation of the principle of utility and Popper’s negative utilitarianism are both examples of satisficing utilitarianism in this sense  and it should be noted that satisficing utilitarianism has the putative advantage over satisfaction satisfice 814    814 optimizing forms of allowing for supererogatory degrees of moral excellence. Moreover, any moral view that treats moral satisficing as permissible makes room for moral supererogation in cases where one optimally goes beyond the merely acceptable. But since moral satisficing is less than optimal moral behavior, but may be more meritorious than certain behavior that in the same circumstances would be merely permissible, some moral satisficing may actually count as supererogatory. In recent work on rational individual choice, some philosophers have argued that satisficing may often be acceptable in itself, rather than merely second-best. Even Simon allows that an entrepreneur may simply seek a satisfactory return on investment or share of the market, rather than a maximum under one of these headings. But a number of philosophers have made the further claim that we may sometimes, without irrationality, turn down the readily available better in the light of the goodness and sufficiency of what we already have or are enjoying. Independently of the costs of taking a second dessert, a person may be entirely satisfied with what she has eaten and, though willing to admit she would enjoy that extra dessert, turn it down, saying “I’m just fine as I am.” Whether such examples really involve an acceptable rejection of the momentarily better for the good enough has been disputed. However, some philosophers have gone on to say, even more strongly, that satisficing can sometimes be rationally required and optimizing rationally unacceptable. To keep on seeking pleasure from food or sex without ever being thoroughly satisfied with what one has enjoyed can seem compulsive and as such less than rational. If one is truly rational about such goods, one isn’t insatiable: at some point one has had enough and doesn’t want more, even though one could obtain further pleasure. The idea that satisficing is sometimes a requirement of practical reason is reminiscent of Aristotle’s view that moderation is inherently reasonable  rather than just a necessary means to later enjoyments and the avoidance of later pain or illness, which is the way the Epicureans conceived moderation. But perhaps the greatest advocate of satisficing is Plato, who argues in the Philebus that there must be measure or limit to our desire for pleasure in order for pleasure to count as a good thing for us. Insatiably to seek and obtain pleasure from a given source is to gain nothing good from it. And according to such a view, satisficing moderation is a necessary precondition of human good and flourishing, rather than merely being a rational restraint on the accumulation of independently conceived personal good or well-being.

Saussure, Ferdinand de 18571913, Swiss linguist and founder of the school of structural linguistics. His work in linguistics was a major influence on the later development of French structuralist philosophy, as well as structural anthropology, structuralist literary criticism, and modern semiology. He pursued studies in linguistics largely under Georg Curtius at the  of Leipzig, along with such future Junggrammatiker neogrammarians as Leskien and Brugmann. Following the publication of his important Mémoire sur le système primitif des voyelles dans les langues indo-européenes 1879, Saussure left for Paris, where he associated himself with the Société Linguistique and taught comparative grammar. In 1891, he returned to Switzerland to teach Sanskrit, comparative grammar, and general linguistics at the  of Geneva. His major work, the Course in General Linguistics 1916, was assembled from students’ notes and his original lecture outlines after his death. The Course in General Linguistics argued against the prevalent historical and comparative philological approaches to language by advancing what Saussure termed a scientific model for linguistics, one borrowed in part from Durkheim. Such a model would take the “social fact” of language la langue as its object, and distinguish this from the variety of individual speech events la parole, as well as from the collectivity of speech events and grammatical rules that form the general historical body of language as such le langage. Thus, by separating out the unique and accidental elements of practiced speech, Saussure distinguished language la langue as the objective set of linguistic elements and rules that, taken as a system, governs the language use specific to a given community. It was the systematic coherency and generality of language, so conceived, that inclined Saussure to approach linguistics principally in terms of its static or synchronic dimension, rather than its historical or diachronic dimension. For Saussure, the system of language is a “treasury” or “depository” of signs, and the basic unit of the linguistic sign is itself two-sided, having both a phonemic component “the signifier” and a semantic component “the signified”. He terms saturated Saussure, Ferdinand de 815    815 the former the “acoustical” or “sound” image  which may, in turn, be represented graphically, in writing  and the latter the “concept” or “meaning.” Saussure construes the signifier to be a representation of linguistic sounds in the imagination or memory, i.e., a “psychological phenomenon,” one that corresponds to a specifiable range of material phonetic sounds. Its distinctive property consists in its being readily differentiated from other signifiers in the particular language. It is the function of each signifier, as a distinct entity, to convey a particular meaning  or “signified” concept  and this is fixed purely by conventional association. While the relation between the signifier and signified results in what Saussure terms the “positive” fact of the sign, the sign ultimately derives its linguistic value its precise descriptive determination from its position in the system of language as a whole, i.e., within the paradigmatic and syntagmatic relations that structurally and functionally differentiate it. Signifiers are differentially identified; signifiers are arbitrarily associated with their respective signified concepts; and signs assume the determination they do only through their configuration within the system of language as a whole: these facts enabled Saussure to claim that language is largely to be understood as a closed formal system of differences, and that the study of language would be principally governed by its autonomous structural determinations. So conceived, linguistics would be but a part of the study of social sign systems in general, namely, the broader science of what Saussure termed semiology. Saussure’s insights would be taken up by the subsequent Geneva, Prague, and Copenhagen schools of linguistics and by the Russian formalists, and would be further developed by the structuralists in France and elsewhere, as well as by recent semiological approaches to literary criticism, social anthropology, and psychoanalysis. 

Scheler, Max 18741928, German phenomenologist, social philosopher, and sociologist of knowledge. Born in Munich, he studied in Jena; when he returned to Munich in 1907 he came in contact with phenomenology, especially the realist version of the early Husserl and his Munich School followers. Scheler’s first works were phenomenological studies in ethics leading to his ultimate theory of value: he described the moral feelings of sympathy and resentment and wrote a criticism of Kantian formalism and rationalism, Formalism in Ethics and a Non-Formal Ethics of Value 1913. During the war, he was an ardent nationalist and wrote essays in support of the war that were also philosophical criticisms of modern culture, opposed to “Anglo-Saxon” naturalism and rational calculation. Although he later embraced a broader notion of community, such criticisms of modernity remained constant themes of his writings. His conversion to Catholicism after the war led him to apply phenomenological description to religious phenomena and feelings, and he later turned to themes of anthropology and natural science. The core of Scheler’s phenomenological method is his conception of the objectivity of essences, which, though contained in experience, are a priori and independent of the knower. For Scheler, values are such objective, though non-Platonic, essences. Their objectivity is intuitively accessible in immediate experience and feelings, as when we experience beauty in music and do not merely hear certain sounds. Scheler distinguished between valuations or value perspectives on the one hand, which are historically relative and variable, and values on the other, which are independent and invariant. There are four such values, the hierarchical organization of which could be both immediately intuited and established by various public criteria like duration and independence: pleasure, vitality, spirit, and religion. Corresponding to these values are various personalities who are not creators of value but their discoverers, historical disclosers, and exemplars: the “artist of consumption,” the hero, the genius, and the saint. A similar hierarchy of values applies to forms of society, the highest of which is the church, or a Christian community of solidarity and love. Scheler criticizes the leveling tendencies of liberalism for violating this hierarchy, leading to forms of resentment, individualism, and nationalism, all of which represent the false ordering of values.