H. P. Grice on P. F. Strawson on "and"

In the identification of * and ' with 4 . ' there is already a considerable distortion of the facts. * And ' can perform many jobs which ' . ' cannot perform. It can, for instance, be used to couple nouns ( 4 Tom and William arrived '), or adjectives ( 4 He was hungry and thirsty'), or adverbs ('He walked slowly and painfully'); while ' . ' can be used only to couple expressions which could appear as separate sentences. One might be
tempted to say that sentences in which * and * coupled words or phrases, were short for sentences in which 4 and ? couples clauses; e.g., that 4 He was hungry and thirsty ' was short for 4 He was hungry and he was thirsty '. But this is simply false. We do not say, of anyone who uses sentences like 4 Tom and William arrived ', that he is speaking elliptic-ally, or using abbreviations. On the contrary, it is one of the functions of * and ', to which there is no counterpart In the case of * . ', to form plural subjects or compound predicates. Of course it Is true of many statements of the forms ' x and y are/* or ' x is /and g \ that they are logically equivalent to corresponding statements of the" form * x Is /and yisf'oT^x is /and x is g \ But, first, this Is a fact about the use, in certain contexts, of the word * and ', to which there corresponds no rule for the use of * . '. And, second, there are countless contexts for which such an equivalence does not hold. For example, c Tom and Mary made friends ' is not equivalent to ' Tom made friends and Mary made friends '. They mean, usually, quite different things (But notice that one could say * Tom and Mary made friends ; but not with one another '. The implication of mutuality in the first phrase is not so strong but that it can be rejected without self-contradiction ; but it is strong enough to make the rejection a slight shock, a literary effect).  Nor does such an equivalence hold if we replace * made friends ' by ' met yesterday *, 4 were conversing \ * got married ' or * were playing chess '. Even * Tom and William arrived ' does not mean the same as * Tom arrived and William arrived ' ; for the first suggests 4 together ' and the second an order of arrival. It might be conceded that * and 5 has functions which 1 . * has not (e.g., may carry in certain contexts an implication of mutuality which c . ' does not), and yet claimed that the rules which hold for * and ', where it is used to couple clauses, are the same as the rules which hold for * . *. Even this is not true. By law (11), " p , q ' is logically equivalent to * q . p ' ; but 4 They got married and had a child ' or * He set to work and found a job ' are by no means logically equivalent to * They bad a child and got married * or 4 He found a job and set to work 1 . One might try to avoid these difficulties by regarding 4 - ' as having the function, not of ' and ', but of what it looks like, namely a full stop. We should then have to desist from talking of statements of the forms ' p .q\ * p . J . r * &CM and talk of sets-of-statements of these forms instead. But this would not avoid all, though it would avoid some, of the difficulties. Even in a passage of prose consisting of several indicative sentences, the order of the sentences may be in general vital to the sense, and in particular, relevant (in a way ruled out by law (II)) to the truth-conditions of a set-of-statements made by such a passage. The fact is that, in general, in ordinary speech and writing, clauses and sentences do not contribute to the truthconditions of things said by the use of sentences and paragraphs in which they occur, in any such simple way as that pictured by the truth-tables for the binary connectives (' D ' * . ', 4 v ', 35 ') of the system, but in far more subtle, various, and complex ways. But it is precisely the simplicity of the way in which, by the definition of a truth-function, clauses joined by these connectives contribute to the truth-conditions of sentences resulting from the junctions, which makes possible the stylized, mechanical neatness of the logical system. It will not do to reproach the logician for his divorce from linguistic realities, any more than it will do to reproach the abstract painter for not being a representational artist; but one may justly reproach him if he claims to be a representational artist. An abstract painting may be, recognizably, a painting of something. And the identification of " ' with * and ', or with a full stop, is not a simple mistake. There is a great deal of point in comparing them. The interpretation of, and rules for, ' . 9 define a minimal linguistic operation, which we might call * simple conjunction ' and roughly describe as the joining together of two (or more) statements in the process of asserting them both (or all). And this is a part of what we often do with ' and ', and with the full stop. But we do not string together at random any assertions we consider true; we bring them together, in spoken or written sentences or paragraphs, only when there is some further reason for the rapprochement, e.g., when they record successive episodes in a single narrative. And that for the sake of which we conjoin may confer upon the sentences embodying the conjunction logical features at variance with the rules for ' . '. Thus we have seen that a statement of the form * p and q ' may carry an implication of temporal order incompatible with that carried by the corresponding statement of the form * q and p \ This is not to deny that statements corresponding to these, but of the forms 4 p . q J and ' q . p ? would be, if made, logically equivalent ; for such statements would carry no implications, and therefore no incompatible implications, of temporal order. Nor is it to deny the point, and merit, of the comparison ; the statement of the form * p . q ' means at least a part of what is meant by the corresponding statement of the form ' p and q \ We might say : the form ' p . q ' is an abstraction from the different uses of the form 4 p and q *. Simple conjunction is a minimal element in colloquial conjunction. We may speak of 4 . ' as the conjunctive sign; and read it, for simplicity's sake, as 4 and ' or ' both . . . and . . .'. I have already remarked that the divergence between the meanings given to the truth-functional constants and the meanings of the ordinary conjunctions with which they are commonly identified is at a minimum in the cases of ' ~ ' and * . '. We have seen, as well, that the remaining constants of the system can be defined in terms of these two. Other interdefinitions are equally possible. But since * ^ ' and 4 . ' are more nearly identifiable with * not ' and ' and } than any other constant with any other English word, I prefer to emphasize the definability of the remaining constants in terms of 4 . ' and * ~ '. It is useful to remember that every rule or law of the system canbeexpressed in terms of negation and simple conjunction. The system might, indeed, be called the System of Negation and Conjunction.