H. P. Grice: Conversation As Rational Co-Operation

H. P. Grice

St. John's, Oxford

H. P. Grice, M. A. Lit. Hum., F. B. A, Tutorial Fellow in Philosophy, St. John's, Oxford.

1938. Negation and privation, negation, 1961, The H. P. Grice Papers, Series II (Essays), carton 4-folders 10-11, BANC MSS 90/135c, The Bancroft Library, The University of California, Berkeley. Keywords: ‘not,’ negation, privation, verificationism, introspection, sense data, sense datum, logical form, unary operator, knowledge, unary functor, incompatibility, Wiggins.  For incompatibility, v. Sheffer, A set of five independent postulates for Boolean algebras, with application to logical constants, Trans. American Mathematical Society, vol. 14. Grice starts with Aristotle's ‘apophasis’ in Int.17a25. The Grice was always lured by the potentiality of a joint philosophical endeavour, and he treasured his collaboration with Strawson that was followed by a collaboration with Austin on Categoriae and De Interpretatione. So what does Aristotle say in ‘De interpretatione’? Surely Aristotle could have started by referring to Plato's ‘Parmenides,’ so aptly analysed by Wiggins. Since Aristotle is more of a don than a poet, he has to give ‘not’ a name. He has: ‘ἀπόφασις ἐστιν ἀπόφανσίς τινος ἀπό τινος,’ a predication of one thing away from another, i.e. negation of it. This is Grice's reflection, in a verificationist vein, of two types of this or that negative utterance. While he uses a souly verb or predicate for one of them, he'll go back to the primacy of 'potching' at a later stage. A pirot potches that the obble is fang. So it is convenient to introduce this or that souly verb. Grice works mainly with two scenarios. Grice’s first scenario concerns a proposition that implies another proposition involving a first-person. The denotatum of the first person perceives that a thing displays this or that  sense-datum. Grice’s second scenario concerns a proposition explicitly mentioning the first person, an introspection, both properly in the first-person ‘I’ with which he is obsessed.  Let’s consider the different variants. 'I don't hear a noise.’ 'I do not hear a noise.’ The second variant gets 'not' in full, seeing what some philosophers have said about elided ‘not’ not carrying this or that presupposition. For the autophoric scenario we have another set of variants. 'I do not hear that the bell tolls.’ Grice fears that a simple-present form may again trigger the wrong implicatum. Thus Grice provides a variant in the non-Anglo-Saxon continuous tense variant. 'I am not hearing that the bell tolls.’ Grice plays with compendious variants. 'I am not hearing a noise.' Grice’s scenario involving a proposition featuring a sense datum involves a visual sense datum, a colour. It can thus be expanded appropriately with the corresponding sensory modal predicate. 'I do not see that the pillar box is blue.’ With neg-lowering, Grice gets a paradoxical variant. 'I see that the pillar box is not blue.’ This is contrasted with ‘I am not seeing that the pillar box is blue.’ Again with neg-lowered we get a different variant. 'I am seeing that the pillar box is not red.’ With elided subject, alla Russell, and Bradley we get still a different variant. 'That is not blue.' Cf. Ryle on a symposium on Bradley on internal relations pre-dating Grice’s essay. Ryle was, as Grice is, invoking Shefferian incompatibility. Ryle was claiming, and rightly so, that the proposition 'This is red' is incompatible with the proposition 'This is not coloured.' Surely, and this is in part Grice’s point, especially when it comes to the visual sense datum scenario, each variant featuring ‘not’ is co-related to some affirmative counterpart. For Grice's introspection case, whose affirmative variants Grice dismisses, we have various affirmative variants. ‘I hear that the bell is tolls.’ Another variant is with the continuous present tense. ‘I am hearing that the bell tolls.’ For Grice's visual sense datum scenario again the variants are multiple. 'I see that the pillar-box is red.’ And the elided form. ‘That is red.’ Grice associates each variant with an explicit (‘hear’) or implicit (‘see’) lower-level psychological or 'souly' state, attitude, or stance, ψ, which may be rendered generally as ‘sensing that’ or ‘perceiving that.’ We have different formulations of the broader ‘communicative’ scenario. For the ‘autophoric’ scenario. By uttering 'I do not hear that the bell tolls,’ the utterer U means that U does not hear that the bell tolls. The utterer’s source, reason, ground, knowledge, or belief, upon which he bases his uttering his utterance is the absence, or absentia, or privatio, or apophasis, verified by introspection, of the co-relative psychological (or souly) state, stance, or attitude, ψ, which Grice links to affirmative counterpart. ‘I  hear that the bell is ringing’ does not feature the 'not' operator. Therefore, it is the proposition Grice is interested in using in the analysans of the negative proposition. For the heterophoric visual sense datum scenario, Grice similarly co-relates the explicitly negative 'I do not see that the pillar box is blue,’ or its elided variant, ‘That is not blue,’ with a slightly similar affirmative counterpart featuring a different colour. The utterer’s ground is not an absence, then, now. Grice invokes the affirmative counterpart proposition itself, featuring ‘red,’ 'I see that the pillar box is red' or the elided 'That is red,' which again does not feature 'not’ and which Grice must use for the analysans. By uttering ‘I do not see that the pillar box is blue,’ the utterer U means that he does not see that the pillar box is blue. Grice alleges it is this affirmative proposition which is the source, reason, ground, knowledge or belief for U to utter 'I do not see that the pillar box is blue,’ or, in the elided variant, 'That is not blue.’ U’s ground is that U sees that the pillar box is red. In the ‘hear’ auditory sense-datum scenario, unlike that the visual sense-datum one, Grice feels he needs not appeal to a different experience, involving a different auditory sense datum, or a sub-modal auditory sense datum (‘I do not hear that the bell tolls in Gb’ vs. ‘I do not hear that the bell tolls in Ab.’ Surely 'I hear that the bell is silent' is illogical.  Cf. ‘I hear that the bell does not toll.’ Had Grice started with 'I hear that the bell tolls in Gb' or  'I hear that the bell tolls in Ab' might have done. If ‘The pillar box is red’ is imcompatible with ‘The pillar box is blue,’ so is ‘The bell tolls in Gb’ with ‘The bell tolls in Ab.’ In the lack of a different auditory experience on the utterer’s part, Grice bases the negative utterance on the utterer's felt absence, absentia, or privatio, or apophasis of the experience, which is thereby negated. The utterance featuring 'not' is explained by the aid of (or reductively analysed in terms of) an introspection, ultimately related to the utterer's confronted with the absence or privation of an experience involving an auditory sense datum, 'I hear that the bell is tolls' simpliciter. The hetero-phoric utterance involving a 'colour' term denotating a visual sense datum and featuring 'not, on the other hand, 'I do not see that the pillar box is blue,' is thus explained in terms, not of an absence or privation of the same experience, but of a different experience involving a different colour word denotating a different visual sense datum. Grice’s thus yields two analysans. Surely he can do with a single one. There are parallels and ways of generalising, using the generic ‘perceiving that’ or ‘sensing that,’ that allow for a unified account. Each pair of affirmative and negative utterance involves a perceptual experience in different sensory modes  ‒ the auditory sensory mode (U's hearing that …) and the visual sensory mode (U's seeing that …), thus generalisable in terms of U's perceiving or sensing, 'I do not sense or sense that the α is φ₁,’ vs. the absence of a possible, potential, but not actualised experience, 'I sense that the α  is φ₁,’ or the presence of the experience involving a different sense datum, 'I perceive or sense that the α  is φ₂.' As he would later put it in Pirotese, the pirot potches that the obble is not fang, but feng. The keyword then would be what Oxonian philosophers refer to as the philosophy of perception (a lower branch of philosophical psychology) which will prove to be a long-standing interest of Grice's, and his close collaborator G. J. Warnock. The important distinction, as Grice observes, is that, by uttering 'That is not red,' U does not explicitly convey, but merely implies, that he is having the perceptual experience and which he attaches to the agent-based first person. Grice does not expand on ‘communication-function,’ such as the 'informative' vs. 'indicative' distinction of the utterance here, but surely it is pretty easy to find conversational scenarios for any of the two scenarios Grice provides. Cf. 'sight unseen.'  By uttering 'I do not hear that the bell tolls,' the U explicitly conveys the perceptual experience attached to the agent-based first person. The ‘auditory’ utterance seems thus like a more natural utterance to receive a direct introspective analysis. Grice must appeal to Scheffer’s incompatibility in terms of the slightly negative-loaded concept of absence, absentia, privation, privation, or apophasis, of a possible, potential, non-actualised experience. Cf. ‘I open the door. I enter the room. I do not see a sight.’ In relying on introspection as a basis for the utterer's knowledge or belief ‒ 'introspective knowledge,' indeed ‒ Grice is being very Oxonian in the best empiricist tradition. Grice's attempt to 'eliminate' 'not' via a reductionist reductive analysis along verificationist empiricist lines succeeds. 'Someone,’ for surely 'I' can always be replaced by the less informative 'someone,' i.e. U, does not see that the pillar box is blue' is based and uttered on the ground that U sees that the pillar box is red. 'Someone, viz. I, does not hear that the bell tolls' is based and uttered on the absence, absentia, privation, privatio, or apophasis of an introspection, or the absence, absentia, privatio, of a possible, potential, but not actualised experience, arrived by introspection and whose content involves the utterer qua ‘perceiver,’ hearing that the bell is tolls, simpliciter, not in Gb or Ab. Meanwhile, at Corpus, Grice is involved in serious philosophical studies under the tutelage of W. F. R. Hardie. While his philosophical socialising is limited, 'having been born on the wrong side of the tracks,’ first at Corpus, and then at Merton, and ending at St. John's, Grice fails to attend the seminal meetings at All Souls held on Thursday evenings by the play group of the seven: J. L. Austin, A. J. Ayer, I. Berlin, S. N. Hampshire, D. MacDermott, D. MacNabb, and A. D. Woozley. Three of them will join Grice in the ‘new’ play group after the war: Austin, Hampshire, and Woozley. But at St. John’s Grice tutors P. F. Strawson, and learns all about the linguistic botany methodology on his return from the navy. Indeed, his being appointed Strawson as his tutee starts a life-long friendship and collaboration. Grice turns back to the topic of 'not' or negation in seminars later at Oxford in the early 1960s  ‒ the MS dated 1961  ‒ in connection with Strawson's cursory treatment of 'not' in ‘Introduction to logical theory’ almost a decade earlier. Grice includes 'not’ as, naturally, the first item, qua unary satisfactory-value-functor (unlike this or that dyadic co-ordinate, ‘and,’ ‘or,’ or the dyadic sub-ordinate ‘if’) in his list of vernacular counterparts to this or that 'formal device,' in this case, ~. Cf. 'Smith has not ceased from eating iron,' in ‘Causal theory.’ In the fourth William James lecture, Grice explores a role for negation along the lines of Cook Wilson's Statement and Inference. Grice's 'Vacuous names' contains Gentzen-type syntactic inference rules for both the introduction (+, ~) and the elimination (-, ~) of ‘not’ or negation, and the correlative value assignation. Grice’s motivation is to qualify 'not' with a subscript scope-indicating device on ‘~' for this or that tricky case like 'The climber of Mt. Everest on hands and knees is not to atttend the party in his honour’. The logical form becomes qualified. ~₂(Marmaduke Bloggs is coming)₁. ~₂(Pegasus flies)₁. The generic formula is ~₂p₁, which indicates that ‘p’ is introduced prior to ‘~.’ In the earlier William James lectures he used the square bracket device. The generic formula being ~[p], where ‘[p]’ reads that ‘p’ is assigned common-ground status. Cancelling the implicata of Grice’s variants in ‘Negation’ may be trickier. ‘That is not blue’ or ‘I am not hearing that the bell tolls’ seems trickier to allow for cancellation, but the task is not impossible. ‘I am not hearing that the bell tolls because I don't exist’ or ‘because there is no me’ is illogical. ‘I do not hear that the bell tolls because it is under reparation’ sounds more natural. ‘That is not blue because that does not exist. Cf. Grice on ‘It is an illusion. What is ‘it’?’. Or ‘That is not blue’ because there is no that.’ Neither seem to eliminate ‘not.’ Cf. 'The king of France is not bald because there is no king of France.' In ‘Presupposition,’ the fourth Urbana lecture, Grice uses square brackets for the subscript scope indicating device. 'Do not arrest [the intruder]!', the device meant to assig common-ground status. In ‘Method in philosophical psychology (from the banal to the bizarre),’ Grice plays with the internalisation of a pre-theoretical concept of 'not' within the scope of a psychological or souly predicate, which may well be the ‘perceiving that’ or ‘sensing that’ that he plays with in ‘Negation,’ denotating a psychological state, stance, or attitude ψ. In the Kant lectures on aspects of reasoning, Grice explores 'not' more seriously within the scope of this or that mode operator, as in the buletic utterance, 'Do not do it!', 'Do not arrest the intruder!’ Grice wonders about the logical form, and implicata, of different variants. Grice offers a choice between ‘!~p,’ where ~ follows the mode operator, and ‘~!p’ where ~ has wider scope. Grice also touches on this or that mixed-mode utterance, and in connection with the minor problem of presupposition within the scope of an operator other than the indicative-mode operator ('Smith has not ceased from eating iron,' because Smith does not exist ‒ cf. Hamlet sees that his father is on the rampants, but the sight is not reciprocated' ‒ 'Macbeth sees that Banquo is near him, but his vision is not reciprocated'). He is having in mind R. M. Hare’s defense of non-doxastic utterance. In his commentary in P. G. R. I. C. E., Grice expands on this metaphysical construction routine of Humeian projection with the pre-intuitive concept of negation, specifying the different stages the intuitive concept undergoes until it becomes fully rationally recostructed, as something like a Fregeian sense. Grice gets most serious in the centerpiece of the William James lecture, as he explores applying Cook Wilson's Statement and inference' to assign a role to 'not,’ and succeeds in finding one. The ‘conversational’ role of ‘not’ is explained in terms of the conversational implicatum. By uttering 'Smith has not been to prison yet,' U implies that some utterer has, somewhere, sometime, expressed an opinion to the contrary. This is connected by Grice with the ability a rational creature has to possess to survive. The creature has to be able, as Sheffer had noted, to deny this or that. Grice’s notable case is the negation of a conjunction. So it may well be that the most rational role for ‘not’ is not primary in that it is realised once less primitive operators are introduced. Is there a strict conceptual distinction, as Grice suggests, between ‘negation’ and ‘privation’? If ‘privation’ involves or presupposes negation, one might appeal to something like Modified Occam’s Razor, do not multiply negations beyond necessity. In his choice of examples, Grice seems to be implicating negation for an empirically verifiable, observational utterance, such as 'U does not see that the pillar box is blue' not because U does not exist, but on the basis of U's knowing, believing and indeed seeing that the pillar box is red. This is a ‘negation, proper, or simpliciter.  Privation, on the other hand, would be involved in an utterance arrived via introspection, such as 'U does not hear that the bell is ringing' on the basis of his knowing that he is aware of the absence of an experience to that effect. Aristotle, or some later Aristotelian, may have made the same distinction, within ‘apophasis’ between ‘negation’ (‘negatio’) and ‘privation’ (‘privatio’). Or not! Of course, Grice is ultimately looking for the rationale behind the conversational implicatum in terms of a principle of conversational helpfulness underlying his picture of conversation as rational co-operation. To use his pirotological jargon in 'Method,' in Pirotese. There is the Pirot₁, who potches that the obble is not fang, but feng. Pirot₁ utters ‘p’ explicitly conveying that p. Pirot₂ alternatively feels like negating that. By uttering ‘~p’, P₂ explicitly conveys that ~p. Pirot₁ volunteers to Pirot₂, ‘~p’, explicitly conveying that ~p. 'Not raining!' Or ‘No bull. You are safe.’ Surely a rational creature should be capable to deny this or that, as Grice puts it in 'Indicative conditionals.' Interestingly, Grice does not consider (as G. J. M. Gazdar does, under F. R. Palmer) the other possible unitary functors (three in a standard binary assignation of values) – just negation, which reverses the satisfactory-value of the radix or neustic.  In terms of systematics, thus, it is convenient to regard Grice’s view on negation (and privation) as his outlook on the operators as this or that procedure by the utterer that endows him with this or that basic expressive, operative power. In this case, the expressive power is specifically related to his proficiency with 'not.’ The proficiency is co-related with this or that device in general, whose vernacular expression will bear a formal counterpart. Many of Grice's comments addressed to this more general topic of this or that satisfactoriness-preserving operator apply to 'not,' and thus raise the question about the explicitum or explicatum of 'not.' A Griceian should not be confused. The fact that Grice does not explicitly mention 'not' or negation when exploring the concept of a generic ‘formal device’ does not mean that what he says about formal device may not be particularised to apply to 'not' or negation. His big concession is that Whitehead and Russell (and Peano before them) are right about the explicitum or explicatum of 'not' being '~.' This is what Grice calls the ‘identity’ thesis to oppose to Strawson’s ‘divergence’ thesis between ‘not’ and ‘~.’ More formally, by uttering 'Not-p,' U explicitly conveys that ~p. Any divergence is explained via the implicatum.' A 'not' utterance is horribly uninformative, and not each of them is of philosophical interest. Grice joked with F. H. Bradley and J. R. Searle's 'The man in the next table is not lighting the cigarette with a twenty-dollar bill,' the denotatum of the subject being a Texas oilman in his country club. The odd implicatum is usually to the effect that someone thought otherwise. In terms of Cook-Wilson, the role of ‘not’ has more to do with the expressive power of a rational creature to deny a molecular or composite utterance such as 'p and q’ Grice comments that in the case of ‘or,’ the ‘not’ may be addressed, conversationally, to the ‘utterability’ of the disjunction. His example involves the logical form ‘Not (p or q)’. It is not the case that Wilson or Heath will be prime minister. There’s always hope for Nabarro or Thorpe.  The utterer is, at the level of the implicatum, not now contradicting what his co-conversationalist has utterered. The utterer is certainly not denying that Wilson will be Prime Minister. It is, rather, that the utterer U wishes not to assert or state, say, what his co-conversant has asserted, but, instead, to substitute a different statement or claim which the utterer U regards as preferable under the circumstances. Grice calls this 'substitutive disagreement.' This was a long-standing interest of Grice’s: an earlier manuscript reads ‘Wilson or MacMillan will be prime minister.’ Let's take a closer look at the way Grice initially rephrases his two scenarios involving 'not' as attached to an auditory and a visual sense datum. ‘I do not hear that the bell is ringing' is rationally justified by the absence (absentia) of the experience of hearing it. ‘I do not see that the pillar box is blue' is rationally justified by U's sensing that the pillar box is red. The latter depends on Kant's concept of the synthetic a priori with which Grice tests with his children's playmates. 'Can a sweater be red and green all over? No stripes allowed!' Can a pillar box be blue and red all over? Cf. Ryle's symposium on negation with Mabbott, for the Aristotelian Society, a source for Grice's reflexion. Ryle later discussing Bradley’s internal relations, reflects that that the proposition, 'This (pillar box is [only] red' is ‘incompatible’ with 'This (pillar box) is [only] blue.' As bearing this or that conversational implicata, Grice’s two scenarios can be re-phrased, unhelpfully, as 'I am unhearing a noise' and 'That is  unred.' The apparently unhelpful point bears however some importance. It shows that 'negation' and ‘not’ are not co-extensive. The variants also demonstrate that the implicatum, qua conversational, rather than conventional, is non-detachable. 'Not' is hardly primtive pure Anglo-Saxon. It is the rather convoluted abbreviation of 'ne-aught.’ It’s 'ne' that counts as the proper, pure, amorphous Anglo-Saxon negation, as in a member of parliament (if not a horse) uttering ‘nay.’  Grice's view of conversation as rational co-operation, as displayed in this or that conversational implicatum necessitates that the implicatum is never attached to this or that expression. Here the favoured, but not exclusive expression, is 'not,' since Strawson uses it. But the vernacular provides a wealth of expressive ways to be negative! Grice possibly chose 'negation' not because, as with this or that 'nihilistic philosopher,' such as Schopenhauer, or indeed Parmenids, he finds the concept a key one. But one may well say that this is the Schopenhauerian or the Parmenidesian [sic] in Griceian. Grice is approaching 'not' in linguistic, empiricist, or conceptual key. He is applying the new Oxonian methodology: the reductive analysis in terms of Russell’s logical construction. Grice’s implied priority is with 'by uttering x (by which U explicitly conveys that ~p), U implicitly conveys that q.’ The essay thus elaborates on this implicated 'q.' For the record, 'nihilism’ was coined by philosopher Friedrich Heinrich Jacobi, while the more primitive ‘negatio' and 'privatio' is each a time-honoured item in the philosophical lexicon, with which mediaeval this or that 'speculative grammarian' is especially obsessed. 'Negatio’ translates Aristotle's 'apophasis,’ and has a pretty pedigreed history. The philosophical lexicon has nĕgātĭo, f. negare, which Lewis and Short, unhelpfully, render as ‘a denying, denial, negation,’ Cic. Sull. 13, 39: ‘negatio inficiatioque facti,’ id. Part. 29, 102. Liddell and Scott go on to add that, in particular, ‘negatio’ referred to a word (or expression) that denies, a negative. Grice would say that Lewis and Short should realise that it’s the utterer who denies. The source Lewis and Short give is App. Dogm. Plat. 3, p. 32, 38. As for Grice's other word, there is “prīvātĭo,” f. privare, which again unhelpfully, Lewis and Short render as ‘a taking away, privation of a thing (class.): ‘doloris,’ Cic. Fin. 1, 11, 37, and 38, or ‘pain-free,’ as Grice might prefer, cf. zero-tolerance. Lewis and Short also cite:‘2, 9, 28: culpæ,’ Gell. 2, 6, 10. The negatio-privation distinction is perhaps not attested in Greek. The Grecians seem to have felt happy with “ἀπόφασις,” “(A),” from ἀπόφημι, which now Liddell and Scott unhepfully render as “ denial, negation,” and they add, “opp. κατάφασις, Pl. Sph. 263e; ἀ. ἐστιν ἀπόφανσίς τινος ἀπό τινος a predication of one thing away from another, i.e. negation of it,” for which Liddell and Scott provide the source that Grice is relying on: Arist. Int. 17a25, cf. APo. 72a14; ἀ. τινός negation, exclusion of a thing, Pl. Cra. 426d; δύο ἀ. ’μίαν κατάφασιν ἀποτελοῦσι‘ Luc. Gall.11. If he was not the first to explore philosophically 'negation,' Grice may be regarded as a philosopher who most explored negation as occurring in a 'that'-clause followed by a 'propositional complexus' that contains ‘~,’ and as applied to a personal agent, in a lower branch of philosophical psychology. It is also the basis for his ‘linguistic’ botany. He seems to be trying to help other philosopher not to fall in the trap of thinking that ‘not’ has a special sense. The utterer means that ~p. In what ways is that to be interpreted? Grice confessed to never been impressed by Ayer. The crudities and dogmatisms seemed too pervasive. Is Grice being an empiricist and a verificationist? Let us go back to 'This is not red' and I am not hearing a noise.' Grice's suggestion is that the ‘incompatible’ fact offering a solution to this problem is the fact that the utterer of 'Someone, viz. I, does not hear that the bell tolls' is indicating (and informing) that U merely entertains the positive (affirmative) proposition, 'Someone, viz. I, hears that the bell tolls,' without having an attitude of certainty towards it. More generally, Grice is proposing, like F. H. Bradley and indeed B. Bosanquet, who Grice otherwise regards as a ‘minor’ philosopher, a more basic subject-predicate utterance. 'The α is not β.' The utterer states 'I do not know that α is β’ if and only if every present mental or souly process, of mine, has some characteristic incompatible with the knowledge that α is β.' One may propose a doxastic weaker version, replacing the dogmatic Oxonian 'know' with 'believe'. Grice's view of 'compatibility' is an application of the Sheffer stroke that Grice will later use in accounts of 'not'. ~p iff 'p|p' or ~p ≡df p|p. But then, as Grice points out, Sheffer is hardly Griceian. If Pirotese did not contain a unitary negative device, there would be many things that a pirot should be able to express that the pirot should be unable to express unless Pirotese contained some very artificially-looking dyadic functor like one or other of the strokes, or the pirot put himself to a good deal of trouble to find, more or less case by case, complicated forms of expression, as Plato’s Parmenides does, involving such expressions as ‘other than,’ or ‘incompatible with.’ V. Wiggins on Plato’s Parmenides in a Griceian key. Such a ‘complicated’ form of expression would infringe the principle of conversational helpfulness, notably in its desideratum of conversational clarity, or conversational ‘perspicuity [sic],’ where the ‘sic’ is Grice’s seeing that unsensitive Oxonians sometimes mistake ‘perspicuity’ for the allegedly, cognate ‘perspicacity’ (L. perspicacitas, like perspicuitas, from perspicere). Grice finds the unitary brevity of ‘not-p’ attractive. Then there's the pretty Griceian idea of the pregnant proposition. 'I'm not hearing a nose' is pregnant, as Occam has it, with 'I am hearing a nose.’ A scholastic and mediæval philosopher loves to be figurative. Grice's main proposal may be seen as drawing on this or that verificationist assumption by Ayer, who actually has a later essay on 'not' falsely connecting it with falsity. Grice's proposed better analysis would please Ayer, had Grice been brought on the right side of the tracks, since it can be subjected to a process of verification, on the understanding that either perception through the senses ('It is red') or introspection ('Every present mental or souly process of mine ...') is each an empirical phenomenon. But there are subtleties to be drawn. At Oxford, Grice's view on negation will influence philosophers like D. Wiggins, and in a negative way, L. J. Cohen, who raises the Griceian topic of the occurrence of 'negation' in embedded clauses, found by Grice to be crucial for the rational genitorial justification of ‘not’ as a refutation of the composite ‘p and q’), and motivating R. C. S. Walker with a reply (itself countered by Cohen  ‒ 'Can the conversationalist hypothesis be defended?). So problems are not absent, as they should not!