Wittgenstein and Moore Paolo Leonardi Received: 7 May 2012 /Accepted: 24 August 2012 / Published online: 19 October 2012 # Springer Science+Business Media Dordrecht 2012 Wittgenstein and Moore would have been a more telling title for Annalisa Coliva's book, because the outline of Moore's defense of common sense- sophisticated, and sympathetic as it is-is preliminary to the discussion of Wittgenstein to come. But it is to Coliva on Moore and to Moore himself that I'll devote most of my attention, touching only on one problem of Coliva's interpretation of Wittgenstein. The book is, however, wholly worth reading: intelligent, rich, informed, well argued and clear.1 Coliva on Moore Coliva first lists Moore's tenets, more or less as Moore himself presents them. Second, she examines Moore's distinction between knowing the meaning of his truisms and analyzing their meaning. (Pp. 16–19) Third, she investigates whether the demonstrative in 'This is a (human) hand' refers to a sense datum. Fourth, she dwells on common sense truths as absolutely true, that is obvious and indubitable. Fifth, Coliva discusses the main literature on Moore on Common Sense and proof of an external world. Sixth, she discusses four understandings of Moore and points out his main claim, viz. the distinction between knowing and being able to prove that one knows. The discussion is about "A Defence of Common Sense" (1925) and "Proof of an External World" (1939), with references to all the relevant texts (such as Moore Philosophia (2013) 41:51–61 DOI 10.1007/s11406-012-9404-3 1These are topics I would have liked to discuss, and will not deal with: Moore's externalism vs Wittgenstein's internalism; a conclusion to knowledge derives from premises we know, and these premises cannot be turned into rules yielding a kind of natural-deduction system; Moore truisms have nothing mental (see 1941: 242) to justify Wittgenstein's repulse as witnessed by Norman Malcolm (Coliva: 29–30); Moore's use of 'I know' is ordinary because it replies to the sceptical objection 'Do you really know?'; finally, I would have touched on Wittgenstein on the argument from dreaming. P. Leonardi (*) Department of Philosophy and Communication, University of Bologna, Bologna, Italy e-mail: paolo.leonardi@unibo.it (1940–44) and (1941)) but Moore's 1910–11 lectures at Morley College, London, published as Some Main Problems in Philosophy only in 1953.2 About "A Defence of Common Sense" Of common sense truisms-sentences such as «There exists at present a living human body, which is my body» –, Moore «maintains that (1) he knows with certainty that they are true when they are about himself; (2) everyone else knows that they are true when they are about himself or herself; (3) he knows, just like everyone else knows of him and of everyone else, that everyone knows with certainty that they are true when they are about each of them.» (Coliva: 14–5.)3 Here are some others common sense truths: "This body was born at a certain time in the past, and has existed continuously ever since, though not without undergoing changes, ... [and] it has been either in contact with or not far from the surface of the Earth", "I am a human being", "I have had many different experiences, of each of many different kinds: e.g., I have often perceived both my own body and other things", "I have not only perceived things ..., but have also observed facts about them", "I have been aware of other facts". What can Moore mean by claiming that his truisms are evident? Does he mean that we immediately know them, with no inference, or rather that they are indubitable? Whatever you think, Moore's knowledge seems to be a mental state of his, the idea that knowledge be a mental state has been discredited by Wittgenstein. Yet, Moore apparent simple-mindedness «conceals three important elements» (p. 24): (i) common sense truths are not the outcome of any intellectual investigation, but something we have known ever since. (ii) That we know the truths of common sense by having being taught other ones-a feature which makes them resemble Wittgenstein's ungrounded presuppositions in On Certainty. (iii) That even if we do not know how we know them, nonetheless we know these truths. Then, Coliva discusses Moore's claims about meaning-he uses words with their ordinary meaning but does not know how to analyze them. Indeed, as she reminds us, in part IV of his 1925 paper, Moore explicitly states that the analysis of perceptual propositions, i.e., propositions grounded on perception, is difficult for him because of his sense data doctrine. I'll come back to this issue later. About "Proof of an External World" The proof as is well known is the following one. Moore says: (1) Here is a hand; then, making the same gesture with the left hand, he adds, (2) Here is another. He then concludes, (3) There are at present two human hands. Since the conclusion concerns the existence of objects which can be met in space, Moore claims that (3) entails 2 Here, Chapter 1 on "What is Philosophy?" states Moore's Common Sense view, and at p. 12 anticipates the 1925 truisms, with the claim that we know them. 3 Here from, any bare reference to pages is to pages of Coliva's own book. 52 Philosophia (2013) 41:51–61 (4) There are physical objects. And hence, that he has proved that (5) There is an external world. Neither the idealist nor the sceptic would be convinced, writes Coliva, but Moore's common sense yields a significant point, i.e., taking apart knowing and proving to know: «I can know things, which I cannot prove; and among things which I certainly did know, even if (as I think) I could not prove them, were the premises of my (...) [proof].» (1939: 150, quoted by Coliva herself.) In closing the chapter on Moore, Coliva remarks that he states that the ground of his proof of the external world is his sense experience. (P. 34, and footnote 58 to Ch. 1.) Then she suggests four ways of understanding Moore's position: (a) as an externalist stance, according to which, notwithstanding Moore's own self-reflective attitude, to know is what is all important, and to prove that we know, to know what grounds our knowledge, isn't required. This stand's consequence would be to give up the project of meeting the sceptical challenge as illegitimate. (b) As an internalist stand, according to which, Moore at most voices a psychological conviction, equivocating knowledge and conviction/certainty. The sceptic epistemic challenge, if Moore were right, would be lost. (c) As a position according to which knowledge is a two strands notion, comprising an externalist and an internalist element «[i]f, we should go by the externalist strand and trust that we know that there is a hand where we seem to see it, even if we can't prove it. (We may eventually draw out the consequences of such a piece of knowledge, for example, that we know that there is an external world). If, in contrast, we are doing epistemology, we may go by the internalist strand and end up denying that we know that there is a hand where we seem to see it or that there is an external world.» (52) (d) As maintaining the stronger suggestion that knowledge is an ambiguous notion. Indeed, the fourth way of understanding Moore is close to acknowledging such an ambiguity. If knowledge is a genus with two species, an externalist and an internalist one, we might wonder what relation, if any, there is between its two species. In any case, Coliva denies that any of the above four understandings would fit Moore. Coliva concludes the chapter hinting that Moore might have anticipated externalism, and attributing him the great merit of individuating a series of propositions ... for which it is a genuine challenge to understand whether we bear an epistemic relation to them. Moreover, he had the merit of expressing, perhaps inappropriately, the commonsensical intuition that no matter how unprovable these propositions turn out to be, we would never give them up. (P. 54). A Fifth Understanding of Moore In the Morley College Lectures, Moore sees common sense as establishing the standard with which to evaluate philosophy, and entrusts the truths of common sense with a special role. Moore remarks that when we know something, either we know it on no proof or our knowledge of it derives from something else which we know. Now, it is not possible that we infer all that we know from something else which we know. If it were so, anything we know would be worse than ungrounded, that is each Philosophia (2013) 41:51–61 53 single knowledge of ours would be dependent on some other knowledge of ours, and we would face a(n infinite) regress or a vicious circle. Hence, if we know anything, there is something we know on no proof.4 Common sense truths are, according to Moore, that something. Not conceding that there are things which I know on no proof empties the concept of knowledge. If a sceptic were not to concede it, she would introduce a substantial change within scepticism. Sceptical objections are against individual claims to knowledge or classes of those, or even against any claim to knowledge. Yet, the sceptic does not object to the concept of knowledge, nor claims it to be an impossible one. Common Sense Truths we Know on no Proof Moore's view of what is a common sense truth is very refined as the famous list of these truisms given in "A Defence of Common Sense" indicates.5 The truisms share nothing with proverbs and the like, nor are the kicking of a stone to prove the existence of an external world. Moore explicitly says he does not know how to analyze those truths, not that they are not analyzable. As Coliva reminds us, he claims that 'I am now perceiving a human hand' is a deduction from a pair of propositions simpler still-propositions which I can only express in the form 'I am perceiving this' and 'This is a human hand.' It is the analysis of propositions of the latter kind which seems to me to present such great difficulties [...] (1925: 53) Moore's problems have an epistemic nature and semantic consequences. His view is the more difficult because of his sense-data theory of perception, whichmakes the path to common sense objects and features not straight. I'll skip any problem concerning Moore's sense-data view. Kids learn to correctly use words such as 'hand', 'I', 'you', 'human body', 'Earth', 'belief', 'knowledge', 'existence', without being able to give an analysis of what a hand, me, you, a human body, the Earth, etc., are. Adults fare better, if requested of an analysis, but still in many cases they don't have a satisfactory grasp.6 Hence, I propose the following core for this claim:Moore could tell a human hand, even if he were unable to tell what 'This is a human hand' involves, and how the concepts voiced by that sentence connect with concepts voiced by other sentences. That is, he understands the sentence and what it is about, but has no theory, or no satisfactory theory, on what it is about, and he doesn't know how he comes to know that this is a human hand.7 Some General Features of Common Sense Truths 1925 What do common sense truths state? They are statements about particulars: my body, this body, the Earth, me, etc. They state existence, attribute general features, such as "I am a human being", to particulars, or attribute them relations with other particulars, as "I have often perceived both my own body and other things". Besides, as we already saw, there are counterparts of those truths for each human being-and that there are, is a common sense truth I know. The 1925 common sense truths, hence, are particular and 4 The issue is examined in Moore 1953, in Ch. 6, on Hume, and the point is stated at p. 123. 5 En passant, Coliva stresses that, see footnote 21 of ch. 1. 6 Moore was hampered by theories of meaning of his time, and we fare only a little better on that too. 7 We can offer an analogously generous reading of Moore's 'I', which disturbed Wittgenstein so much. 'I' in 'I know' is normalized, as I believe it is proper according to how Moore uses it, by claiming an antiindividualistic understanding of 'I'. 54 Philosophia (2013) 41:51–61 idiosyncratic truths. Each human being has access to her or his own (perspectival) truisms, and she or he knows the others to have their counterparts of his or her own truisms. Common Sense Truths 1939 "Proof of an External World" introduces a remarkable change. Though its focus aren't common sense truths, the two proofs Moore gives of the existence of an external world-the first proving the existence of two human hands at the time when he gave the proof; the second proving the existence of two human hands at the time previous to that at which he gave the proof-use common sense truths. The proof of the existence of an external world is not the proof of a truism, as the complex definitional work which Moore does before getting to the proof shows. In the 1925 jargon, this part is an analysis of 'external world'. The analysis defines intermediary properties such as "to be a thing to be met in space", and it is argued, for instance, that a hand is a thing of that kind. Here is a variant of the 1939 proof, which starts from a 1925 truism: I say «This is a human body», pointing to my body. Hence, "There are human bodies", from which we derive "There are physical objects", and finally conclude "There is an external world".8 Now, a common sense truth in the 1939 style, I suggest, is the intermediary sentence, which is a perfectly general existential statement. That is, the common sense truths in the 1939 style are the same for each and all of us, and it is not anymore the case that I have my own particular ones, and you have your own particular ones, though the ones are counterparts of the others. Moreover, in the 1939 style, you can well give the above proof, pointing to my body, and saying «This (Here) is a body.»9 Let me take stock. Moore first analyzes what knowledge is: for there to be knowledge there has to be knowledge with no proof. Hence, he finds statements, which are a blend of general and particular sentences, presenting an unanalyzed content. "There is here a such", "There is here a such and such", etc. Finally, Moore distinguishes between some fully particular sentences, truths which a particular individual knows, and a set of general statements, the same set of statements, which each individual derives from the particular thing she or he knows. These are common sense truths, the same ones, accessible to anyone of us. The Analysis of Common Sense Truths The quest for knowledge as a common enterprise and a personal adventure starts here, according to Moore, and it produces an analysis of the objects, features, and relations mentioned in those sentences. Common sense truths constrain the enterprise, in that any theory of what and how things are encompasses the entities introduced by common sense truths. Truisms say nothing about the nature of the things they introduce, and it may well be that a theory 8 If I am right, 1939 common sense truths are perfectly impersonal, as it is perfectly impersonal another truth we can infer from 'I know this is a hand', i.e. 'Someone knows there is a hand'. Moore considers the impersonality of a statement such as the last one and of some consequences of asserting it. Of course, the truth of 'Somebody knows that p' remains dependent on some person knowing p. (1941: 240–1) 'I know that p' is an instance of one such particularization and is the format Norman Malcolm first, and Wittgenstein later, disliked so much. Reversing the 1939 proof we can come to understand that the debate over the external world is a debate over our hands, our bodies, etc. Nothing mystical. 9 Although a different kind of proof, as Coliva stresses, Descartes' cogito starts from "I exists", "I am", which is a sentence of the same form of Moore's premises. Philosophia (2013) 41:51–61 55 of these things shows them not to be ontologically basic. Common sense truths are cognitively basic, not ontologically such. For all that, common sense à laMoore isn't a theory, nor can be overcome by or reduced to a theory, be it philosophical or scientific. How do the Common Sense Truths Fare Against the Sceptic? By maintaining his truisms, Moore denies radical scepticism. Stroud 1984, for instance, suggests that, facing a sceptical question-"How do you know ...?"-Moore shows that there is a most natural way of understanding and answering it, which skips any sceptical reading of the question. On the contrary, Moore aims at countering the radical sceptic in a proper way. The sceptic puts in doubt any claim to knowledge, and Moore makes some. Do his claims stand the sceptical challenge? Part of the evidence for a Moorean claim is the evidence of the senses. I look at my left hand and realize that there is a hand there. The fact that it is logically possible that what seems a hand is an illusion, that I am hallucinating or dreaming, etc., does not make it likely that there isn't a hand. This is often dismissed as irrelevant evidence against the sceptic. It isn't irrelevant: if we know that something is more likely than not, we already know something.10 Moreover, notice the following. What we are running is a discursive piece of reasoning. When we run one such reasoning, we have a set up sensory-motor system (and memory as well) and master a language. Indeed, we are able both to decode (auditory, graphic, gestural) signs, and to implement and effectively use these signs. If we could use with confidence neither our sensory-motor nor our language system, we couldn't run any such reasoning. In particular, we couldn't run the present reasoning, because we wouldn't know what we are presently sounding and hearing-phonemes would be noises, graphemes patches. As well, the sceptic could not raise her question. It is only by accepting some facts that we can come to doubt and correct some claims. Accordingly, the sceptical question isn't preliminary to acknowledging the truisms, and if Moore is right, it is then internal to the knowledge enterprise.11 Moore's choice of basic facts shows that his argument is reflexive-it uses what it aims to posit-and sophisticated, because: (a) sceptics doubt not our sensations but what can be projected from them; (b) ingenuous perception is distal (proximal perception is the product of a theoretical construction)12; (c) if we don't trust our senses and more generally our cognitive abilities, we can do nothing-thinking is impossible without trusting memory and perception, and discursive thinking is 10 Cf. Moore 1941, 240–3. Coliva quotes the evidence of the senses part. At footnote 40, Ch 1, Coliva judges irrelevant that in the case Moore's claim is more certain than the sceptic's. But Moore uses 'certain', which he doesn't use to express a subjective judgment. 11 It is very important that truisms concern everyday objects, properties and relations. They are not only perceptual, though, including knowledge of the Earth and its age, etc. Their ordinariness makes them more stable. The list is a philosophical reconstruction of a framework we learn when kids. The case of learning our mother tongue's sounds is more complicated to tell, but starts from the first day of life, and its basic semantics is acquired in the first 1–2 years. Learning takes place in between biological endowment and raising in a culture. As Moore suggests, he has learnt these thing very early on and does not remember when or where from. 12 Against Berkeley, Moore 1903 argues that we cannot speak of sensations but as sensations of, with an objective genitive. The argument can perhaps be used also against the much more phenomenic rendering of sensation by Hume 1739 (see Book I, Part IV, II), which is a proximal rendering of ingenuous sensation. 56 Philosophia (2013) 41:51–61 impossible without linguistic competence; (d) Moore's truisms are contingent truths.13 Three Last Remarks First, internally to the knowledge enterprise, scepticism plays a significant role. In order to yield knowledge, we continuously watch out, and are ready to revise, articulate, substitute, add or take out something. Second, our knowledge of truisms is ascriptive. In each single case, finding defective aspects, opting for some other truisms, we can revise the ascription.14 Third, even if some grounds of a 1939 common sense truth, i.e., some judgment, such as 'This is an F', turned out false, if our senses are mostly right, some other judgments would ground the common sense truth. Wittgenstein on Certainty Here are a few remarks on Wittgenstein on certainty, and on Coliva's interpretation of Wittgenstein. The book dedicates three chapters, about 3/4 of its length, toWittgenstein, discussing in sequence his analysis of (Moorean) 'I know', Wittgenstein's view of scepticism as nonsensical, and his reply to a Cartesian and a to Humean sceptical argument,Wittgenstein on (propositional) hinges, in which Coliva discusses the groundlessness of his foundationalism. The leit-motiv of the analysis is that Moore's truisms in Wittgenstein hands become grammatical norms. Hence, they are something to which we do not have an epistemic relation and which is neither true nor false. The sentences expressing such norms do not play a double role, being (at the same time) a norm and an empirical statement. I think Wittgenstein was more hesitant than Coliva makes him on viewing truisms as norms. The term 'norm' occurs four times in On Certainty (1967), in one case with a different sense. Here are the three relevant occurrences (the fourth is in the footnote at the end of the quotes): 167. It is clear that our empirical propositions do not all have the same status, since one can lay down such a proposition and turn it from an empirical proposition into a norm of description. Think of chemical investigations. Lavoisier makes experiments with substances in his laboratory and now he concludes that this and that takes place when there is burning. He does not say that it might happen otherwise another time. He has got hold of a definite world – picture – not of course one that he invented: he learned it as a child. I say world-picture and not hypothesis, because it is the matter-of-course foundation for his research and as such also goes unmentioned. [Italics mine.] 321. Isn't what I am saying: any empirical proposition can be transformed into a postulate-and then becomes a norm of description. But I am suspicious even 13 The whole first part of Moore 1941 is explicitly and exclusively devoted to this aspect. This is what fascinated Wittgenstein about Moore 1925. 14 Pryor (2004) speaks of perception as offering Moore immediate justification. My sketch of Moore's case is different. Moore offers, I think, a reflective justification. In the years Moore was developing his common sense philosophy, Otto Neurath introduced the metaphor of the boat rebuilt at sea for the search for knowledge. (1932/33 [1983]: 92) Philosophia (2013) 41:51–61 57 of this. The sentence is too general. One almost wants to say "any empirical proposition can, theoretically, be transformed ... ", but what does "theoretically" mean here? It sounds all too reminiscent of the Tractatus. [Italics mine.] 634. "I can't be making a mistake; and if the worst comes to the worst I shall make my proposition into a norm." [Italics mine.] 15 The third quote is almost ironic. The first two quotes mention a norm of description. Already the name, 'norm of description' is peculiar, but not less special is, in § 167, the example involving Lavoisier who runs one experiment and takes it that things might not «go otherwise another time». If Lavoisier has discovered a natural regularity, has he discovered a norm of description in a strictly normative sense or in the sense that normally things go that way? Is it a norm of description or a description of a normal course of events or state of affairs? What has he been learnt as a child? In § 321 Wittgenstein looks even more uncertain to be facing a norm of description rather than an empirical proposition. The term 'rule' occurs less rarely than the term 'norm', and clearly often as a variant on it. There is a telling passage: 87. Can't an assertoric sentence, which was capable of functioning as an hypothesis, also be used as a foundation for research and action? I.e., can't it simply be isolated from doubt, though not according to any explicit rule? It simply gets assumed as a truism, never called in question, perhaps not even ever formulated. An assertion, wonders Wittgenstein, might be turned into a standard for research and action, not explicitly, i.e., as an unformulated truism never called in question. The issue is not about the implicit assumption but about the status of what one assumes- is it something to which neither truth nor falsity apply? Is it a series of matters of fact, or a few principles, a few norms? Wittgenstein hesitates, I believe. Sometimes he insists in attributing a double role and status to sentences expressing these matters of fact or those principles. 98. But if someone were to say "So logic too is an empirical science" he would be wrong. Yet this is right: the same proposition may get treated at one time as something to test by experience, at another as a rule of testing. Some other passages are harder to straight up. For instance: 140. We do not learn the practice of making empirical judgments by learning rules: we are taught judgments and their connection with other judgments. A totality of judgments is made plausible to us. To which category do judgments belong? There are passages closer to Coliva's reading: 15 Indeed there is a seemingly different use of 'norm' too: 473. Just as in writing we learn a particular basic form of letters and then vary it later, so we learn first the stability of things as the norm, which is then subject to alterations. 58 Philosophia (2013) 41:51–61 494* "I cannot doubt this proposition without giving up all judgment." But what sort of proposition is that? (It is reminiscent of what Frege said about the law of identity.) It is certainly no empirical proposition. It does not belong to psychology. It has rather the character of a rule. In 494, Wittgenstein still wonders, but his proclivity is clearer. In general, however, Wittgenstein seems uncertain about subscribing to that reading. Here are some other quotes: 308. [...] What interests us now is not being sure but knowledge. That is, we are interested in the fact that about certain empirical propositions no doubt can exist if making judgments is to be possible at all. Or again: I am inclined to believe that not everything that has the form of an empirical proposition is one. 309. Is it that rule and empirical proposition merge into one another? 319. But wouldn't one have to say then, that there is no sharp boundary between propositions of logic and empirical propositions? The lack of sharpness is that of the boundary between rule and empirical proposition. 452. It would not be reasonable to doubt if that was a real tree or only. ...My finding it beyond doubt is not what counts. If a doubt would be unreasonable, that cannot be seen from what I hold. There would therefore have to be a rule that declares doubt to be unreasonable here. But there isn't such a rule, either. 519. [...] But since a language-game is something that consists in the recurrent procedures of the game in time, it seems impossible to say in any individual case that such-and-such must be beyond doubt if there is to be a language-game- though it is right enough to say that as a rule some empirical judgment or other must be beyond doubt. Sections 308, 309, 319 show how difficult it is for Wittgenstein to distinguish hinges from empirical propositions-notwithstanding his inclination («I am inclined», 308). Section 452 denies that there can be a rule making unreasonable a doubt about being a tree there; but that one such doubt is unreasonable cannot be seen either in what I hold or in a rule. The sense of 'rule' in the last quote is different from the one 'rule' seems to have in the previous quotes, and I understand it as if 'rule' here amounted to default value, in most cases, a matter of fact regularity, or the like. Is what said to be beyond doubt an empirical judgment? Moore and Wittgenstein can be made closer, giving what is due to Coliva defense of truisms as norms.16 I have already reverted to Moore's claim that he knows the meaning of common sense truths but is unable to analyze them. Now, I surmise that that knowledge of Moore's amounts to this. Truisms make explicit the reference of our terms, taking notice of distinct things, of particulars by a proper name, or 16 To my knowledge Wright was the first to suggest understanding truism as rules of evidence (Wright 1985). Coliva's own view is more complex and is well illustrated at pp. 156–9. Philosophia (2013) 41:51–61 59 locally by a demonstrative, and of their qualities by predicative or relational names.17 Moore's truisms can then be reduced, I think, to cases of name placing (proper, predicative, relational -name placing), and hence to empirical sentences with grammatical consequences. The idea can be reformulated in two ways at least. One way is to claim that truisms are coordinative definitions à la Reichenbach. One such definition coordinates concepts with objects in (physical) science. Relevant is the case of units of measurement: In principle, a unit of length can be defined in terms of an observation that does not include any metrical relations, such as "that wave-length which occurs when light has a certain redness." In this case a sample of this red color would have to be kept in Paris in place of the standard meter. The characteristic feature of this method is the coordination of a concept to a physical object. (1928: 15) A coordinative definition transforms an instance in a standard, linking the objectual plane with the linguistic-conceptual one. It does not give any information on the world, but allows to start collecting it. As it is well known, metric standards are never definitive: we reflect on the ones we have chosen and try to find better standards, which can afford us a more precise measure. The same happens with language, whose semantic fields are in a dynamic state, possibly changing, and hopefully refined, on any occasion of use. A second way to look at the idea is the contingent a priori. Speaking of the same case Reichenbach was examining in the section on coordinative definitions, i.e., the standard meter, Saul Kripke describes fixing the standard meter by the bar in Sévres as an instance of contingent a priori, i.e., as a definition which fixes a reference. (1972 [1980]: 56–57) Common sense truisms fix the reference of basic terms of any investigation. As Wittgenstein writes: 139. Not only rules, but also examples are needed for establishing a practice. Our rules leave loop-holes open, and the practice has to speak for itself. In an example, a name and the thing named come together.18 Truisms make explicit our reference frame. As such, they play the role of a standard, which has a normative aspect to it. Moore has it as the acknowledgement of a matter of fact, of a contingent truth. Wittgenstein stresses the role of a standard. Coliva is closer to Wittgenstein's understanding, I am closer to Moore's. Wittgenstein's reading almost misses something which is philosophically relevant, I believe, that is, that at the start there are some contingent truths. Since the Tractatus (1921), Wittgenstein sees the contingency of the world and the necessity of language 18 Section 139, like many sections among the first fifty of On Certainty, discusses rules along the same lines of the Philosophical Investigations. Going along those lines would make it difficult to identify a rule with its formulation, as it would have to be if we speak of normative propositions, as Coliva argues in Ch. 4. 17 Even George Berkeley writes: I do not argue against the existence of any one thing that we can apprehend either by sense or reflexion. That the things I see with my eyes and touch with my hands do exist, really exist, I make not the least question. (1710, §35) Much harder is Hume's position. 60 Philosophia (2013) 41:51–61 and logic, and faces many a problem on how to relate language and state of affairs. Reichenbach and Moore have a way out, and Wittgenstein looks at it with bewilderment, somehow uncertain. References Berkeley, G. (1710). A Treatise Concerning the Principles of Human Knowledge. Kripke, S. 1972 [1980]. "Naming and Necessity" (in Semantics of Natural Language. D., Davidson, G., Harman, eds. 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(2004). What's Wrong with Moore's Argument? Philosophical Issues, 14, 349–78. Reichenbach, H. (1928) [1958] Philosophie der Raum-Zeit-Lehre (English tr. The Philosophy of Space and Time New York Dover). Wittgenstein, L. (1921). "Logisch-Philosophische Abhandlung" (Annalen der Naturphilosophie 14: 185– 262; Eng. tr. by C.K. Ogden with an introduction by B. Russell Tractatus Logico-Philosophicus London Routledge & Kegan Paul 1922). Wittgenstein, L. (1967). On Certainty (Oxford Blackwell). Wright, C. (1985). "Facts and Certainty" (Proceedings of the British Academy 71: 429.72). Philosophia (2013) 41:51–61