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PHIS phis_136 Dispatch: 7-22-2008 CE: N/A Journal MSP No. No. of pages: 23 PE: Kristen 1 Philosophical Issues, 18, Interdisciplinary Core Philosophy, 2008 2 3 4 5 6 7 8 9 KNOWLEDGE AND CERTAINTY 10 11 12 13 Jason Stanley 14 Rutgers University 15 16 17 18 What is the connection between knowledge and certainty? The question 19 is vexed, in part because there are at least two distinct senses of “certainty”. 20 According to the first sense, subjective certainty, one is certain of a propo- 21 sition if and only if one has the highest degree of confidence in its truth. 22 According to the second sense of “certainty”, which we may call epistemic 23 certainty, one is certain of a proposition p if and only if one knows that 24 p (or is in a position to know that p) on the basis of evidence that gives 25 one the highest degree of justification for one’s belief that p. The thesis that 26 knowledge requires certainty in either of these two senses has been the basis 27 for skeptical arguments. For example, according to one kind of skeptical 28 argument, knowledge requires epistemic certainty, and being epistemically 29 certain of a proposition requires having independent evidence that logically 30 entails that proposition. Since we do not have such evidence for external 31 world propositions, we do not know external world propositions. According 32 to another kind of skeptical argument, due to Peter Unger (1975), knowledge 33 requires subjective certainty, and we are never subjectively certain of any 34 proposition. So, we never know any proposition. 35 Some authors have responded to these skeptical arguments by adopting 36 fallibilism about certainty, the doctrine that having the highest degree of 37 justification for a belief does not involve the possession of logically entailing, 38 non-question begging grounds for that belief (Miller (1978), Klein (1981, 39 Chapter 3)). But my interest in this paper does not lie in rebutting skeptical 40 arguments based upon the assumption that knowledge entails certainty. 41 Rather, my purpose is to establish that knowledge does not require certainty 42 in either of these two senses. Even if we are certain of many things, knowing 43 that p does not entail subjective or epistemic certainty. 44 Since the claim that knowledge requires certainty (in either sense) is 45 closely associated with detrimental conclusions, the central case for the phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 connection has typically been made on intuitive rather than normative 3 grounds. For example, it seems that someone is speaking falsely when they 4 assert “I know that Bush is president, but I’m uncertain of it.” The kinds of 5 arguments I will focus on in this paper involve such appeals to our intuitions 6 about various claims about the relation between knowledge and certainty. So 7 I will not be giving a normative argument about the nature of knowledge or 8 the nature of the various kinds of certainty. My goal is rather to contrast the 9 intuitive grounds for the claim that knowledge requires certainty (in either 10 sense) with the intuitive grounds for the claim that knowledge requires truth, 11 belief, or justification. I will argue that the evidence that has been marshaled 12 in support of the thesis that knowledge requires certainty is instead far better 13 explained by the hypothesis that we adhere to norms that connect subjective 14 and epistemic certainty with the speech act of assertion. 15 In the hands of the contextualist in epistemology, the arguments for the 16 thesis that knowledge requires certainty become arguments for the thesis 17 that “knowledge” requires “certainty”. My own view is that contextualism 18 about knowledge attributions is false, but that “certain” is a context- 19 sensitive adjective. So I am a contextualist about “certain”, but not about 20 instances of “know that p”. Be that as it may, my arguments that knowledge 21 requires certainty are also arguments that “knowledge” does not require 22 “certainty”. 23 24 25 1. 26 27 Peter Unger’s argument for his novel form of skepticism involves two 28 premises, only the first of which will be of interest to me in this paper. The 29 first premise is that “If one knows, then it is all right for one to be certain” 30 (1975, p. 98). We do not need to be concerned here with what Unger means 31 by the somewhat normative notion of being “all right for one to be certain”. 32 My concern is rather with Unger’s claim that knowledge in fact requires 33 certainty. As Unger writes (Ibid.): 34 35 The very particular idea that knowing entails its being all right to be certain is 36 suggested, further, by the fact that knowing entails, at least, that one is certain. 37 As we saw in section 9 of the preceding chapter, that this is a fact is made quite 38 plain by the inconsistency expressed by sentences like ‘He really knew that it was 39 raining, but he wasn’t absolutely certain it was.’ Such a sentence can express no 40 truth: if he wasn’t certain, then he didn’t know. 41 42 Unger’s focus is on the notion of subjective certainty, rather than epis- 43 temic certainty. Though the term “certain” is ambiguous between subjective 44 and epistemic certainty, there are constructions in which it only can be read as 45 the former than the latter, and vice-versa. When one speaks of a person being phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 certain of a proposition, it is subjective certainty that is at issue. In contrast, 3 when one speaks of a proposition being certain, it is epistemic certainty that 4 is at issue. So, in a sentence such as “John is certain that Bush is president”, 5 it is subjective certainty that is at issue, whereas when one says “It is certain 6 that Bush is president”, what is at issue is the epistemic certainty of the 7 proposition that Bush is president, relative to one’s own body of evidence. 8 Unger’s arguments concern subjective certainty, as do his examples. 9 How do we convince our undergraduates that knowledge requires truth, 10 belief, and justification? One way is via consideration of the oddity of 11 sentences such as “He knew that snow is purple, even though snow isn’t 12 purple”, or “He knew that snow is white, but he didn’t believe that snow is 13 white”, or “He knew that snow is white, but he had no reason to believe it”. 14 That is, the intuitive basis for the thesis that knowledge requires truth, belief, 15 and justification is the oddity of instances of the schemas in (1)-(3): 16 17 (1) X knows that p, but p is false. 18 (2) X knows that p, but X doesn’t believe that p. 19 (3) X knows that p, but X has no reason to believe that p. 20 21 Unger’s argument that knowledge requires subjective certainty is of the same 22 sort. Just as instances of (1)-(3) sound odd, so instances of (4) sound odd: 23 24 (4) I know that p, but I’m not certain that p. 25 26 Unger is right that instances of (4) sound odd. Given that the oddity of 27 instances of (1)-(3) is good evidence that knowledge requires truth, belief, 28 and justification, the oddity of (4) provides good evidence that knowledge 29 requires subjective certainty. 30 Unger’s focus is on the notion of subjective certainty. But there are 31 analogous arguments to Unger’s for the conclusion that knowledge requires 32 epistemic certainty. Instances of (5) are just as odd as instances of (1)-(4): 33 34 (5) I know that p, though it isn’t certain that p. 35 36 In fact, an utterance of a sentence such as (6) is also quite odd: 37 38 (6) He knows that Bush is president, though it isn’t certain that Bush is 39 president. 40 41 Together, these facts provide an argument of the very same form for 42 the conclusion that knowledge requires epistemic certainty, in addition to 43 subjective certainty. 44 There are reasons philosophers have given to reject connections between 45 knowledge and justification, or even knowledge and belief. So, the fact that phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 instances of (2) and (3) sound odd might be part of a folk theory of knowledge 3 that we may reject on philosophical grounds. Nevertheless, these facts provide 4 evidence that, according to our folk theory of knowledge, knowledge does 5 require belief and justification. Many philosophers have a similar attitude 6 towards the connection between knowledge and certainty. They grant that 7 the oddity of instances of (4) and (5) provide evidence that our folk theory of 8 knowledge connects knowledge and subjective and epistemic certainty. They 9 argue that we should instead adopt a fallibilist conception of knowledge that 10 severs these connections. 11 But the case that knowledge requires certainty in either sense was 12 never meant to establish that knowledge ought to require certainty. Rather, 13 the argument is that the oddity of instances of (4) and (5) shows that 14 we intuitively think that knowledge does in fact require certainty. Most 15 epistemologists who have emphasized such connections have used it to argue 16 for distressing conclusions. Their attitude towards attempts to explicate a 17 fallibilist notion of knowledge that lacks this connection to certainty has 18 been to emphasize that the connection between knowledge and certainty is 19 so deeply ingrained, that any attempt to eliminate it will not preserve central 20 features of the knowledge relation (e.g. the discussion of fallibilism in Lewis 21 (1996)). 22 23 24 2. 25 26 There are a number of normative considerations in favor of the thesis that 27 knowledge requires truth, belief, and justification. But it also has an intuitive 28 basis. It clearly is odd to speak of someone knowing something clearly false, 29 or knowing something without believing it. The case for the alleged relation 30 between knowledge and certainty does not rest upon some desirable feature 31 of the knowledge relation. Typically, it is a premise in arguments for skeptical 32 conclusions. Because of this, we should expect that the descriptive case for 33 the link between our actual concept of knowledge and the notion of certainty 34 is at least as strong as the descriptive case for the constitutive link between 35 knowledge and truth. 36 If knowing a proposition requires that proposition to be true, we would 37 expect (7) to sound like an assertion of a trivial conceptual truth and (8) to 38 sound like an assertion of an obvious falsity: 39 40 (7) Everything anyone knows is true. 41 (8) There is something someone knows that isn’t true. 42 43 (7) is obviously true, and (8) obviously false. Similarly, if knowing a 44 proposition requires believing that proposition, then we should expect (9) 45 to be a trivial truth and (10) to be obviously false: phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 (9) Everything someone knows she believes. 3 (10) There is something someone knows that she doesn’t believe. 4 5 Finally, if knowing a proposition requires having evidence for that proposi- 6 tion, we would expect (11) to sound like a trivial truth and (12) to sound 7 obviously false: 8 9 (11) If someone knows something, she has a reason to believe it. 10 (12) There is something someone knows that she doesn’t have any reason 11 to believe. 12 13 An assertion of (11) certainly seems true, and (12) seems false. 14 If it is intuitively obvious that knowledge requires subjective certainty, 15 we should expect (13) and (14) to seem like banal truths and (15) to seem 16 obviously false: 17 18 (13) I’m certain of everything I know. 19 (14) Everyone is certain of everything she knows. 20 (15) There are some things I know, of which I’m only fairly certain. 21 22 However, (13) and (14), unlike (7), (9), and (11), do not sound like banal 23 truths. An utterance of (15) also does not share the obvious sense of falsity 24 of (8), (10), and (12). Similarly, if knowledge requires epistemic certainty, we 25 should expect (16) to be a banal truth, on a par with (7) and (9), and we 26 should expect (17) to seem clearly false, on a par with (8), (10), and (12): 27 28 (16) Everything I know is certain to be true. 29 (17) There are some things I know, which are only fairly certain to be 30 true. 31 32 But (16) does not seem like a banal truth, and (17) seems perfectly in order. 33 A further dissimilarity between the case for the factivity of knowledge 34 (the entailment from knowledge to truth) and the case for the entailment from 35 knowledge to subjective certainty involves the existence of an asymmetry in 36 our intuitions between first person and third person reports. Unger is right 37 that an instance of (4) sounds odd: 38 39 (4) I know that p, though I’m not completely certain that p. 40 41 But third-person reports of the form of (4) are not as odd as utterances of 42 (4). For example, compare (18) with (19): 43 44 (18) John knows that Bush is a Democrat, though Bush isn’t a Demo- 45 crat. phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 (19) John knows that Bush is a Republican, though, being a cautious 3 fellow, he is only somewhat certain of it. 4 5 (18) is obviously false. By contrast, (19) is not at all obviously false. So there 6 is an asymmetry between first-person and third-person ascriptions in the 7 case of the alleged relation between knowledge and certainty, an asymmetry 8 that is lacking in the case of the relation between knowledge and truth (or 9 knowledge and belief). 10 There is an asymmetry between first and third person reports of 11 knowledge without subjective certainty. But this asymmetry is not present 12 where “certain” has an epistemic use. For example, (21) is just as odd as (20): 13 14 (20) I know that Bush is president, though it’s not certain that he is. 15 (21) John knows that Bush is president, though it’s not certain that he 16 is. 17 18 So, while there is an asymmetry between first and third person reports 19 of subjective certainty. But this asymmetry disappears in the case of epistemic 20 certainty. 21 If one proposition obviously entails another, it will feel redundant to 22 follow an assertion of one with an assertion of the other. So, redundant 23 conjunctions provide evidence of entailments. In the case of the relation 24 between knowledge and truth, we clearly see such evidence of entailment, as 25 is witnessed by the oddity of (22): 26 27 (22) I know that Bill came to the party. In fact, he did. 28 29 We also see similar evidence in the case of the relation between knowledge 30 and belief, as (23) is just as odd as (22): 31 32 (23) I know that Bill came to the party. In fact, I believe he did. 33 34 The reason (22) and (23) are odd is that knowing entails truth and belief. No 35 new information is conveyed by assertions of the second sentences in (22) 36 and (23). So, the utterances seem pointless, and the discourses odd. 37 In contrast, we see no such evidence of entailments in the case of 38 subjective and epistemic certainty. In both cases, there is no similar sense 39 of redundancy: 40 41 (24) I know that Bill came to the party. In fact, I’m certain that he did. 42 (25) I know that Bill came to the party. In fact, it’s certain that he did. 43 44 The discourses in (24) and (25), in contrast to those in (22) and (23), do 45 not seem odd at all. The assertions of the second sentences seem to add phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 new information to the information expressed by “I know that Bill came to 3 the party”. If knowledge entailed subjective and epistemic certainty, this fact 4 would be a mystery. The discourses in (24) and (25) would be just as odd as 5 the discourses in (22) and (23). If knowledge does not entail subjective and 6 epistemic certainty, this fact is explicable.1 7 Another way we convince our undergraduates that knowledge requires 8 truth is we ask them to consider claims such as: 9 10 (26) John knows that snow is purple. 11 12 (26) is clearly false. Similarly, if it is quite clear that John doesn’t at all believe 13 that snow is white, then one cannot ascribe to him the knowledge that snow 14 is white. But correspondingly lucid intuitions are lacking in the case of the 15 alleged connection between knowledge and certainty. It does no violence at 16 all to our use “know” to ascribe knowledge of a proposition to someone who 17 is somewhat uncertain of it. As Unger points out (Unger, 1975, p. 83-4): 18 19 Thus typical in the contemporary literature is this sort of exchange: An examiner 20 asks a student when a certain battle was fought. The student fumbles about and, 21 eventually, unconfidently says what is true: The Battle of Hastings was fought 22 in 1066. It is supposed, quite properly, that this correct answer is a result of the student’s reading. The examiner, being an ordinary mortal, and so unconfident 23 of many things himself, allows that the student knows the answer; he judges 24 that the student knows that the Battle of Hastings was fought in 1066. Surely, it 25 is suggested, the examiner is correct in his judgment, even though this student 26 clearly isn’t certain of the thing... 27 28 Unger’s example shows that we easily accept attributions of knowledge to 29 people who are not subjectively certain. 30 The intuitions linking knowledge and subjective and epistemic certainty 31 seem to provide a case for an entailment between knowledge and certainty 32 parallel to the entailment between knowledge and truth, or knowledge and 33 belief. But once we canvass a broader range of cases, the parallel between 34 knowledge and certainty, on the one hand, and knowledge and truth, or 35 knowledge and belief, on the other, becomes considerably less compelling. 36 There is nothing odd about ascribing knowledge of a proposition to someone 37 who has less than the highest degree of confidence in her belief in it. In 38 contrast, it is clearly incorrect to ascribe knowledge of a false proposition 39 to someone. In so doing, one has asserted something false. There are many 40 asymmetries between the relation that holds between knowledge and truth, 41 on the one hand, and the alleged relation between knowledge and certainty, 42 on the other. Though there are a series of complicated facts that Unger has 43 drawn to our attention that require an explanation, it is now evident that the 44 hypothesis of a constitutive connection between knowledge and subjective or 45 epistemic certainty is ill-suited to be part of it. phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 Unger is aware of some of these points. As we have seen, he readily 3 concedes that many of his “paradoxical” sounding sentences are in fact 4 quite clearly intuitively acceptable. But Unger maintains that this is due to 5 the fact that we normally allow language to be used loosely. According to 6 Unger, in order to focus upon the actual meaning of a term, we need to place 7 focal stress on that term. Whereas (19) is acceptable, a sentence such as (27) 8 is not: 9 10 (27) He actually knows it’s a Cadillac, but he’s not absolutely certain. 11 12 Unger argues that focal stress is a way of drawing attention to literal 13 meaning, and when we place focal stress on “know” and “certain”, the 14 oddity of knowledge without subjective certainty emerges. Unger thereby 15 inadvertently draws attention to a further disanalogy between the relation 16 between knowledge and truth (or belief), on the one hand, and knowledge 17 and subjective certainty, on the other. We do not need the device of focal 18 stress at all to detect the falsity of ascriptions of knowledge of clearly false 19 propositions. 20 21 22 3. 23 24 Unger’s reaction to the fact that we do not flinch when someone is 25 described as knowing something of which she is not certain is to argue that 26 in such cases, we are not “focused on actual meaning”. As Unger writes 27 (Ibid., p. 74), in response to a hypothetical objector dubious of Unger’s 28 “flatness” skepticism (according to which hardly any surface is actually flat): 29 30 According to your account, he notes, ‘flat’ means the same as ‘absolutely flat’. 31 Thus, the simplest hypothesis for you is that sentences of the form ‘x is flat’ always 32 are equivalent in meaning to ones of the corresponding form ‘x is absolutely 33 flat’, at least when ‘x’ is not meant to pick out some old beer, etc. This creates something of a problem for you: When people say things like ‘That is flat; 34 the other is flatter’, your account would have them saying something which is 35 inconsistent, something which must always be false. But, the sentence doesn’t 36 sound inconsistent. And, indeed, it really does seem that sentences of this sort 37 are often used to say things which are true. How are to you account for such 38 blatant discrepancy? 39 40 Unger’s response to the hypothetical objector is to argue that in cases in 41 which we accept assertions such as ‘That is flat, the other is flatter’, it is 42 because we allow terms to be used in loose and distorted ways, ways that are 43 not reflective of “actual meaning”. Similarly, when we allow someone who is 44 uncertain of p to be described as knowing that p, we are allowing the term 45 “know” to be used loosely. phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 Unger’s own meaning hypotheses are principally motivated by appeal to 3 our intuitions about various cases. It is therefore incumbent upon Unger to 4 provide tests to distinguish intuitions that reflect “actual” meaning from 5 intuitions that are corrupted by our tendency to allow speakers to use 6 language loosely. Unger does so by providing methods of improving what 7 he calls our “Focus on Actual Meaning”. These tests centrally involve focal 8 stress. As Unger writes (1975, p. 76): 9 10 Emphasis does not change the meaning of words or sentences to which it is 11 applied. Thus the sentence ‘He killed her’ means the same as the sentence ‘He 12 killed her’. The first will express what is true if and only if the second does...In 13 any case, the importance of emphasis does not derive from any effect on meaning 14 or truth. Quite the contrary, its importance in our language derives from its 15 having no such effect. Shouldn’t we have some device(s) to attract attention to 16 a term which work in a way that does not effect (sic) the term’s meaning, or the 17 meanings of sentences of which that term is a part? 18 19 For Unger, the function of focal stress in our language is to “focus on actual 20 meaning”. 21 Unger acknowledges that it is a fact that we do not flinch when 22 attributing knowledge that p to those who are clearly not certain that p. 23 His response is to argue that we are speaking loosely (not in accord with 24 the literal meanings of the terms), and the fact that we are speaking loosely 25 emerges when we place focal stress on the relevant expressions, as in examples 26 like: 27 28 (28) He actually knows it’s a Cadillac, but he’s not absolutely certain. 29 30 The fact that (28) sounds contradictory is explained by the fact that the 31 function of focal stress in natural language is to focus on actual meaning, 32 and the actual meaning of “know” involves absolute certainty. 33 As Unger recognized, his claim that stress “does not effect (sic) the term’s 34 meaning, or the meanings of sentences of which that term is a part” had been 35 seriously threatened in work done by Fred Dretske (1972), who argued that 36 stressing a term does affect the meaning of sentences of which that term is 37 a part. Dretske emphasized the intuitive difference in meaning between (29) 38 and (30): 39 40 (29) The reason Clyde married Bertha was to qualify for the inheritance. 41 (30) The reason Clyde married Bertha was to qualify for the inheritance. 42 43 Suppose that Clyde must marry within a year to qualify for his inheritance. 44 He has no wish to give up his bachelor lifestyle, so he decides to marry Bertha, 45 his lesbian friend, in order to meet this requirement. Intuitively, (29) is true phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 relative to this situation, and (30) is false. Conversely, suppose that Clyde is 3 dating Bertha and Hannah. Clyde decides he wants to marry one of them, 4 and has a preference for Hannah. But he will not qualify for his inheritance 5 if he marries a Jew, and so he decides to marry the Christian Bertha instead. 6 Relative to this situation, (30) is true and (29) is false. Dretske’s work suggests 7 that the purpose of focal stress is not to “focus on actual meaning”, but rather 8 to interact with salient sets of contrasts to the focal element in the sentence. 9 Operators such as “the reason” are sensitive to this interaction. 10 Unger (Ibid., pp. 78ff.) provides a pragmatic account of the intuitions 11 concerning (29) and (30). By stressing “married” in (29), the speaker 12 is drawing our attention to one aspect of the event being explained— 13 namely, the marrying part of the event (similarly, by stressing “Bertha” in 14 (30), the speaker is drawing our attention to another aspect of the event 15 being explained—namely that its patient was Bertha). Qualifying for the 16 inheritance is the sole explanation for why the event of Clyde marrying Bertha 17 was a marrying event. But it is not the sole reason for the event of Clyde 18 marrying Bertha. Therefore, according to Unger’s pragmatic account of (29), 19 though the speaker’s utterance is felicitous, what she asserts is nevertheless 20 false, since qualifying for the inheritance was not the reason Clyde married 21 Bertha. 22 Unger’s pragmatic account of Dretske’s data does not do justice to the 23 generality of the phenomenon. Consider the well-known contrast between 24 (31) and (32): 25 26 (31) Bill only introduced John to Frank. 27 (32) Bill only introduced John to Frank. 28 29 An utterance of (31) is true if and only if Bill introduced John to Frank, 30 and Bill did not introduce anyone other than John to Frank. In contrast, an 31 utterance of (32) is true if and only if Bill introduced John to Frank, and 32 Bill did not introduce John to anyone other than Frank. It is unclear how to 33 generalize Unger’s pragmatic explanation of the felicity of (29) and (30) to 34 (31) and (32). Just as “the reason that” interacts with the focused expression 35 in (29) and (30), “only” interacts with the focused expression in (31) and 36 (32), and the interaction results in a difference in truth conditions.2 37 Unger’s claim that placing focal stress on a term does not affect the truth- 38 conditions of larger sentences containing it is false.3 But more germane to 39 our concerns is Unger’s contention that placing focal stress on a term does 40 not alter its actual meaning.4 According to Unger, pronouncing sentences 41 with flat intonation results in a content communicated that is thoroughly 42 affected by pragmatic processes, and the way to eliminate the effects of 43 these pragmatic processes is to appeal to focal stress. This is a strange view, 44 from a contemporary perspective. We certainly do not yet understand all the 45 ways in which focus interacts with context. But one thing all linguists agree phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 upon is that focusing an expression introduces a myriad variety of pragmatic 3 effects, depending upon the type of intonation, effects which are eliminated 4 if one pronounces the relevant sentence with flat intonation. Though matters 5 are never straightforward where focus is concerned, if anything it is flat 6 intonation which allows us to “focus on actual meaning”. 7 Unger’s general view of focus is incorrect. But he is right that it is odd 8 to say, of someone who has a good deal of evidence that Bush is president 9 in 2006, but is somewhat unconfident: 10 11 (33) He just knows that Bush is president. 12 13 Similarly, sentences such as (34) also seem quite odd: 14 15 (34) He really knows that Bush is president, though he’s not completely 16 certain. 17 18 19 It is one thing to dismiss Unger’s theoretical justification for taking such 20 utterances at face-value; it is quite another to explain their oddity without 21 impugning the doctrine that knowledge does not require certainty. 22 I do not have an explanation for what is going on with stressed uses 23 of “know”. But consideration of a wider range of cases might make us 24 suspicious of allowing such uses to guide our hypotheses about literal 25 meaning. For example, suppose, reading a newspaper on the day after the 26 election, I discover that Bush in fact won the election. It would be quite 27 ordinary for me to respond: 28 29 (35) How could this have happened? I knew that Kerry was going to 30 win. 31 32 Or suppose, having found out that my friend did not after all cheat me: 33 34 (36) Boy, I just knew you had cheated me. I’m so relieved to find out I 35 was wrong. 36 37 One would surely not want to take these uses of “know” as showing that 38 the actual meaning of “know” did not require truth. But even if we did 39 take stressed uses of “know” to be indicative of actual meaning, Unger’s 40 thesis that knowledge is incompatible with uncertainty would be no more 41 plausible. There are more direct arguments against his dual contentions that 42 focal stress brings out actual meaning, and that this undermines the thesis 43 that knowledge is consistent with subjective uncertainty. Here is an example 44 from a different context.5 Suppose that I am watching my favorite college 45 basketball team on what I know to be tape-delay on television, and they are phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 down by 15 points with 10 minutes to go. No one has told me the final result. 3 But, knowing my team, I felicitously say: 4 5 (37) I know they are going to lose. But I guess there is a chance they’ll 6 pull it out in the end, so I’ll continue watching. 7 8 Unger thinks that focal stress is a way to focus on actual meaning. So he 9 is committed to taking the stressed use of “know” at face-value. Surely, 10 the epistemic possibility of ∼p is incompatible with knowing that p. So 11 Unger needs to take the stressed use of “chance” to be a way of talking of 12 subjective credence. So, by Unger’s lights the apparent truth of (37) shows 13 that knowledge does not require certainty after all. 14 15 16 4. 17 18 Though the case for the thesis that knowledge requires certainty is 19 extraordinarily weak, Unger is correct that instances of (38) are invariably 20 odd, as are instances of (39): 21 22 (38) I know that p, but I’m not certain that p. 23 (39) I know that p, but it’s not certain that p. 24 25 This is the last vestige of the argument that knowledge requires subjective 26 and epistemic certainty. We have seen that it cannot support the conclusion 27 that knowledge requires certainty. So there must be some other explanation 28 of the oddity of utterances of instances of (38) and (39). 29 In the case of the relation between knowledge and truth, there is no 30 asymmetry between first person claims and third person claims. In other 31 words, instances of (40) and (41) are clearly odd: 32 33 (40) I know that p, though p is false. 34 (41) She knows that p, though p is false. 35 36 The oddity of instances of both (40) and (41) seems to emerge from the same 37 source, namely obvious falsity. In contrast, as we have seen, instances of (42) 38 are not anywhere nearly as odd as instances of (38) (imagine an instance 39 of (42) used to describe a cautious yet eminently renowned expert on the 40 subject matter in question): 41 (42) She knows that p, though she’s only somewhat certain of it. 42 43 If knowledge entailed subjective certainty, as knowledge entails truth, then 44 the existence of the asymmetry between first person and third person cases 45 would be utterly mysterious. So there is some other explanation of the phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 oddity of instances of (38). We have also seen that there is a clear contrast 3 between quantified versions of (40) and (41), and quantified cases involving 4 knowledge and subjective and epistemic certainty, such as (13) and (16). 5 This pattern of intuitions completely vitiates an explanation that appeals to 6 entailments between knowledge and subjective or epistemic certainty. 7 A clue to the correct explanation of Unger’s evidence comes from the 8 fact that sentences such as (43) and (44) are just as odd as instances of (38) 9 and (39): 10 11 (43) Dogs bark, but I’m not certain that they do. 12 (44) Dogs bark, but it’s not certain that they do. 13 14 (43) and (44) are instances of “Moore’s Paradoxical” utterances, such as: 15 (45) Dogs bark, but I don’t know that they do. 16 (46) Dogs bark, but I don’t believe that they do. 17 18 Assertions of (43)-(46) are odd, and their oddity presumably is due to some 19 fact about conversational norms. The fact that (38) and (39) are just as odd 20 as cases of Moore’s paradox with “certain” suggests the desirability of a 21 uniform explanation. 22 Unger (1975, p. 259) quite clearly recognizes the fact that the oddity of 23 an assertion of (38) is due to the same source as the oddity of an assertion 24 of (43): 25 26 We may explain the apparent inconsistency of ‘It’s raining, but I’m not absolutely 27 sure that it is’ by making an assumption about knowing and being absolutely 28 sure. We need only suppose that one’s knowing something to be so entails one’s 29 being absolutely sure of it. 30 Unger (Ibid., p. 260) proposes the following account of the fact that an 31 utterance of (43) is odd: 32 33 We may think, for example, that the person just represented himself as knowing 34 that p, and not as being absolutely certain that p. Understanding this repre- 35 sentation, we in turn quickly realize that what he represented entails that he is 36 absolutelycertainthatp,whichhethengoesontodeny. 37 38 This account proposed by Unger appeals to the knowledge account of 39 assertion, which is: 40 41 The Knowledge Norm for Assertion: Assert that p only if you know 42 that p. 43 44 According to the account, the knowledge norm for assertion, together with 45 the principle that knowledge entails subjective certainty, explains the fact that phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 utterances of (43) are odd; an analogous entailment in the case of epistemic 3 certainty would explain the oddity of utterances of (44). But the principle 4 that knowledge entails certainty (in either sense) is false. So this account is 5 unhelpful in explaining the oddity of (43) and (44). 6 The fact that knowledge does not entail certainty shows that we cannot 7 derive an explanation of the oddity of (43) by appeal to the Knowledge 8 Norm for Assertion. But perhaps we can reverse the strategy, and account 9 for the lure of the Knowledge Norm by appeal to The Certainty Norm for 10 Assertion:6 11 12 The Certainty Norm for Assertion: Assert that p only if you are certain 13 that p. 14 15 The Certainty Norm for Assertion explains the oddity of (43). If there were 16 a certainty norm for assertion, one could both explain away the intuitions 17 behind the claim that knowledge entails certainty, as well as the existence 18 of Moore’s paradoxical utterances involving “certain”. However, since there 19 is good reason to reject an entailment from knowledge to certainty, one 20 cannot derive this norm, as Unger suggests, from the knowledge account of 21 assertion. 22 Utterances of both (43) and (44) are odd. This suggests that accounting 23 for all of the evidence requires two certainty norms of assertion: 24 25 The Subjective Certainty Norm for Assertion: Assert that p only if you 26 are subjectively certain that p. 27 28 The Epistemic Certainty Norm for Assertion: Assert that p only if you 29 are epistemically certain that p. 30 31 The existence of these norms for assertion straightforwardly explains the 32 oddity of (43) and (44), in the same way in which the knowledge account of 33 assertion explains the oddity of (45). It remains to be seen how these norms 34 of assertion can be brought to bear to explain the oddity of all versions of 35 Moore’s paradox. 36 Subjective certainty is a context-sensitive matter, and its relation to full 37 belief is vexed. Nevertheless, I take it that whatever the level of subjective 38 certainty is in a context, it is at least as strong as the level of confidence 39 required for full belief. Since subjective certainty entails full belief, the 40 subjective certainty norm for assertion can explain the oddity of instances of 41 Moore’s Paradox involving “believes”, such as (46), in exactly the same way 42 as the proponent of the knowledge account of assertion explains them (e.g. 43 Williamson (2000, p. 254)). 44 The issue is slightly more complex in the case of instances of Moore’s 45 Paradox involving “know”, such as (45). Consider the proposition that there phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 are no large Jewish elephants in my bedroom. This may have been an 3 epistemic certainty for me five minutes ago, even though I did not know 4 that there were no large Jewish elephants in my bedroom. I did not know 5 that there were no large Jewish elephants in my bedroom, because I did not 6 believe it, and I did not believe it simply because it didn’t occur to me ever 7 to entertain that possibility. Nevertheless, in this case, if I had entertained 8 the proposition that there are no large Jewish elephants in my bedroom, I 9 would have known it. The reason this counterfactual is true is because it is 10 an epistemic certainty for me that there are no large Jewish elephants in my 11 bedroom. So the fact that a proposition is an epistemic certainty for a person 12 does not entail that the person knows that proposition. If a proposition is an 13 epistemic certainty for a person at a time, then it does follow that the person 14 is in a position to know that proposition. Being in a position to know a 15 proposition is to be disposed to acquire the knowledge that that proposition 16 is true, when one entertains it on the right evidential basis. Since epistemic 17 certainty entails possession of this dispositional property, utterances of (45) 18 are odd.7 19 So, all versions of Moore’s paradox (with belief, knowledge, and cer- 20 tainty) would be explained by the invocation of the dual certainty norms 21 for assertion. In contrast, the knowledge account of assertion, according to 22 which assertion is governed by a norm for knowledge, can only explain the 23 belief versions of Moore’s paradox, such as (45). In order to account for the 24 certainty versions of Moore’s paradox, such as (43) and (44), the advocate of 25 the knowledge account of assertion must embrace a contextualist account 26 of knowledge ascriptions, according to which we have “a reluctance to 27 allow the contextually set standards for knowledge and certainty to diverge” 28 (Williamson, 2000, p. 254). But this is problematic. First, contextualism 29 about knowledge ascriptions is a problematic view about the semantics of 30 knowledge ascriptions. Secondly, it forces the advocate of the knowledge 31 account of assertion to adopt the position that a knowledge ascription can 32 only express a truth relative to a context of use if the corresponding certainty 33 ascription expresses a truth in that context. But, as we have seen, neither the 34 view that knowledge entails certainty, nor the view that “knowledge” entails 35 “certainty”, is plausible. 36 The certainty norms for assertion also explain the patterns of symmetry 37 and asymmetry between first and third person reports. As Unger realized, 38 a third-person report of knowledge despite lack of subjective certainty is 39 perfectly in order: 40 41 (19) John knows that Bush is a Republican, though, being a cautious 42 fellow, he’s somewhat uncertain of it. 43 44 The fact that (19) is fine, but instances of (38) are not, is straightforwardly 45 explained by the fact that we adhere to a norm of subjective certainty for phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 assertion. These norms also explain why there is no such asymmetry in the 3 case of epistemic certainty: 4 5 (20) I know that Bush is president, though it’s not certain that he is. 6 (21) John knows that Bush is president, though it’s not certain that he 7 is. 8 9 An utterance of (21) is just as odd as an utterance of (20), because the use of 10 “certain” is linked to the knowledge base of the person making the assertion; 11 an utterance of (21) expresses the proposition that John knows that Bush 12 is president, though, given the knowledge base of the person making the 13 assertion, it’s not certain that Bush is president. The oddity of this assertion 14 is explained by the epistemic certainty norm for assertion, together with the 15 fact that knowledge is factive. In order for Hannah to assert that John knows 16 that Bush is president, she must be epistemically certain of it; but then, by 17 the factivity of knowledge, she must also be epistemically certain that Bush 18 is president. So the oddity of Hannah’s utterance of (21) shows that Hannah 19 must be epistemically certain that John is president in order to assert it. But it 20 does not show that John must be epistemically certain that Bush is president 21 in order to know that Bush is president. So there is no route from the oddity 22 of utterances of (21) to a constitutive connection between knowledge and 23 epistemic certainty. 24 Finally, there are non-Moorean considerations in favor of the certainty 25 norms for assertion. One natural way to challenge an assertion is, as 26 advocates of the knowledge norm of assertion have emphasized (Williamson 27 (2000, pp. 252-3)), to utter “How do you know?” But it is equally natural, 28 when confronted by someone making an assertion on inadequate grounds, 29 to respond with “Are you sure?” Without appeal to contextualism about 30 knowledge ascriptions, the knowledge norm of assertion can only explain 31 the former sort of challenge, but not the latter. If however the norms for 32 assertion involve in the first instance certainty, rather than knowledge, the 33 naturalness of both of these kinds of challenges is explicable. 34 The certainty account of assertion can explain all the data that motivates 35 the knowledge account of assertion, but not vice-versa. Furthermore, at- 36 tempts to explain the data that motivate the knowledge account of assertion 37 with weaker norms of assertion, such as the truth norm (Weiner, 2005) 38 or the reasonable-to-believe norm of assertion (Lackey, forthcoming) do 39 not generalize to account for the kind of data that motivates the certainty 40 norms for assertion. For example, according to Weiner (2005), the truth 41 norm of assertion can account for Moore’s paradoxical utterances involving 42 “know”. According to him, this is because someone who asserts that p 43 while disclaiming knowledge that p is construed as not possessing warrant 44 to follow the truth rule. However this explanation may fare in explaining 45 Moore’s paradoxical utterances involving “know”, it does not generalize to phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 explain Moore’s paradoxical utterances involving “certain”, such as (43) and 3 (44), nor does it explain why we often demand certainty, and not merely 4 knowledge, of our interlocutors.8 5 6 7 5. 8 9 Perhaps, like the knowledge account of assertion, there is only one 10 certainty norm for assertion, and the other is derivative. For example, perhaps 11 assertion primarily requires subjective certainty. One could explain the work 12 done by the norm of epistemic certainty by appealing to norms governing 13 subjective certainty. One such norm is: 14 15 16 The Epistemic Certainty Norm for Subjective Certainty: Be subjec- 17 tively certain that p only if you are epistemically certain that p. 18 19 On the assumption that epistemic certainty is a norm for subjective certainty, 20 it may be possible to reduce the twin norms of assertion to a single norm of 21 subjective certainty. Here is how the defender of the single subjective certainty 22 norm for assertion would explain the oddity of Moorean utterances such as 23 (45). First, an utterance of “Dogs bark” would implicate that the speaker is 24 subjectively certain that dogs bark. If the speaker is adhering to the norms 25 of subjective certainty, then she is also epistemically certain that dogs bark, 26 and hence knows that dogs bark. The oddity of (45) is due to the fact that 27 asserting “dogs bark” implicates that the speaker knows that dogs bark, 28 via the subjective certainty norm for assertion, together with the epistemic 29 certainty norm for subjective certainty. 30 One worry for this approach is that the fact that epistemic certainty is a 31 norm for subjective certainty might not ‘transfer’ to explaining the Moorean 32 oddity of utterances of (45). For example, it is plausible that knowledge is 33 the norm of belief. Nevertheless, utterances of (47) are perfectly in order: 34 35 (47) I believe that dogs bark, but I don’t know it. 36 37 The fact that utterances of (47) are in order suggests that the fact that 38 knowledge is a norm of belief does not mean that an utterance of an instance 39 of “I believe that p” implicates that the subject knows that p. Similarly, even 40 if epistemic certainty is a norm for subjective certainty, it would not follow 41 that presumed adherence to a norm of subjective certainty would implicate 42 that the agent is epistemically certain of the relevant proposition. However, 43 the function of using “I believe” in (47) is to qualify support for the truth 44 of a proposition, rather than endorse it. In short, such uses of “believe” are 45 not cases in which one reports a belief that p at all; they are rather cases in phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 which one reports that one has weak reasons in support of the truth of a 3 proposition.9 4 An alternative way to pursue the thought that there is just one certainty 5 norm for assertion is to defend the view that assertion primarily requires 6 epistemic certainty. The requirement of subjective certainty would be a 7 derivative norm. Subjective certainty, unlike epistemic certainty, is under 8 the rational control of an agent. Rational agents who seek to adhere to the 9 norm of epistemic certainty would manifest their adherence by only asserting 10 propositions of which they were subjectively certain. Instead of governing the 11 act of assertion, the norm of subjective certainty would emerge from rational 12 requirements on an agent’s adherence to the norm of epistemic certainty.10 13 In what follows, I will assume for the sake of discussion that the 14 fundamental constitutive norm governing the act of assertion is the epistemic 15 certainty norm for assertion, and that the subjective certainty norm has a 16 derivative status. 17 The familiar rivals to the knowledge account of assertion are less 18 demanding norms for assertion, such as the truth norm, the belief norm, 19 and the warranted belief norm. In contrast, the epistemic certainty norm for 20 assertion is an even more demanding norm than the knowledge norm. But 21 the argument for the more demanding norm for assertion is of the same form 22 as the argument for the knowledge norm for assertion. The certainty norm 23 for assertion explains all versions of Moore’s Paradox, and does so without 24 commitment to contextualism. Furthermore, there are additional reasons for 25 the more demanding norm, which stem from the nature of testimony. 26 It is an intuitive thought about testimony that someone who acquires 27 a belief via testimony has less justification for it than the person who 28 transmitted the belief. But this thought is in tension with the thesis that 29 communication is a reliable means for transmitting knowledge. If A knows 30 that p, and informs B, and neither A nor B has any defeating reasons for their 31 belief that p, then B thereby comes to know that p, even if A is her only source. 32 But then if the person who asserts that p only just satisfies the conditions 33 for knowing that p, then the belief formed on the basis of her assertion will 34 not amount to knowledge. For communication to be a guaranteed method 35 of transmitting knowledge between agents with no defeating reasons, the 36 assertor must be in a better epistemic position with regard to p than just 37 knowing that p. In short, the epistemic certainty norm for assertion is one 38 way to explain the consistency between the thesis that assertion is a method 39 of transmitting knowledge, and the thought that testimony does not preserve 40 strength of evidential position towards a belief. 41 If knowledge is the norm for full belief, then the epistemic certainty 42 norm for assertion places a greater demand upon assertion than the norms 43 governing full belief. This is problematic, if occurrent belief is thought of as a 44 kind of inner assertion. But this model of occurrent belief ignores the public 45 character of the practice of assertion. When someone asserts something, she phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 takes on the commitment of transmitting her knowledge of it to her inter- 3 locutor. On the assumption that acquiring a belief via testimony results in 4 having a weaker epistemic position towards the content of that belief than the 5 one from whom one has acquired the warrant to believe it, it makes perfect 6 sense that assertion would have a more demanding norm than full belief. 7 One might worry that the twin norms of certainty are impossibly 8 demanding. For example, if subjective certainty is construed as credence 1, 9 then being subjectively certain of a proposition requires that one would bet 10 on it, no matter what the odds. Similarly, if epistemic certainty is construed 11 as knowing a proposition on non-circular logically entailing grounds from a 12 priori premises, then epistemic certainty requires Cartesian certainty. Thus 13 construed, the claim that there are certainty norms governing assertion is 14 impossibly demanding. 15 The main point of my paper has been to argue that knowledge does not 16 entail certainty of any kind. If one holds that certainty is not achievable, then 17 if the certainty norm is what explains instances of Moore’s Paradox, it follows 18 that no one can satisfactorily meet the norms governing assertion. Skepticism 19 about certainty undermines warranted assertion, but since knowledge does 20 not entail certainty, skepticism about certainty does not entail skepticism 21 about knowledge. On the picture I have defended, skepticism about certainty 22 would suggest that we mistakenly demand overly restrictive conditions on 23 asserting, ones that we in fact never meet. 24 But skepticism about certainty should be rejected. Unger’s skeptical 25 argument that we are never certain of anything depended crucially upon 26 his “method of focusing on actual meaning”. Unger’s skeptical argument 27 has two premises: first, that knowledge requires certainty, and secondly, that 28 we are certain of almost nothing. We have already seen that the failure of this 29 method undermines Unger’s case for the first premise. But it also undermines 30 Unger’s case for the second premise. 31 According to Unger, the adjective “certain” is what he calls an absolute 32 term. An absolute term, by Unger’s lights, is one that only holds of things at 33 the end of the relevant scale. According to Unger, “flat” is an absolute term; 34 it holds only of the flattest thing in the universe. Unger’s argument that “flat” 35 is an absolute term is that by “focusing on actual meaning” we recognize that 36 if x is flatter than y, then y isn’t flat at all. Unger also argues that “certain” is 37 an absolute term. There is good reason to believe that the class of adjectives 38 Unger picks out as absolute form a linguistically distinctive class. 39 The fact that absolute adjectives form a distinctive class does not save 40 Unger’s skeptical argument that absolute adjectives are never in fact true of 41 anything. As we have seen, Unger is utterly clear that an unstressed use of 42 (48) is perfectly in order, as is an unstressed use of (49): 43 44 (48) That is flat; that other is flatter. 45 (49) Though John is certain that Bush is president, he’s even more certain that he’s not going to vote Republican anymore. phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 The way that Unger argues that (48) and (49) actually are false is by appeal 3 to his method of focusing on actual meaning. The fact that this is not a 4 way to identify actual meaning undermines Unger’s skeptical argument for 5 regarding absolute adjectives. The fact that “flat”, “straight”, and “certain” 6 are associated with endpoints in the way that they are in no way entails 7 that it is not the case that plenty of things satisfy “flat”, “straight”, and 8 “certain”. 9 Here is a brief sketch of a context-sensitive semantics for “certain”. On 10 either of its interpretations, “certain” accepts modifiers such as “absolutely” 11 or “completely”. So “certain”, in both its subjective and epistemic uses, is 12 an absolute gradable adjective. “Certain” is context-sensitive in two ways. 13 First, it is context-sensitive as regards the kind of scale relevant to its 14 interpretation (a scale of confidence or a scale consisting of degrees of 15 justification). Secondly, it is context-sensitive as regards the degree on the 16 scale that is required to satisfy the property it expresses, relative to that 17 context. A person’s belief satisfies the property expressed by a subjective use 18 of “certain” relative to a context if and only if that person holds that belief 19 at or above the contextually salient degree of confidence; mutatis mutandis 20 for epistemic certainty and degrees of justification. 21 Just as many beliefs may satisfy “certain”, many beliefs may, in context, 22 satisfy “absolutely certain”. The semantic function of “absolutely” is to raise 23 the degree on the scale above that for “certain”. So in any context, it will 24 be harder for a belief or a proposition to satisfy “absolutely certain” than it 25 will be for it to satisfy “certain”. But it still is possible for a belief to satisfy 26 “absolutely certain” in one context, while not satisfying “absolutely certain” 27 (or even “certain”) in another. 28 Assuming this contextualist semantics for “certain”, the norms governing 29 assertion are naturally to be understood meta-linguistically; assert that p in 30 a context only if your confidence in p meets the contextually salient standard 31 for “certain” at that context, as well as the contextually salient standard of 32 justification that is required for epistemic certainty. When I assert that the 33 store is open, I am adhering to the norm of subjective certainty for assertion 34 provided only that I would also be licensed to declare in that context that 35 I am sure that the store is open, i.e. that I meet the contextually salient 36 standard for “certain”. Construed this way, the notions of certainty relevant 37 for the norms of assertion are nowhere near as demanding as willingness to 38 bet on a proposition no matter what the odds, or having Cartesian grounds 39 for its truth. 40 The fact that I am sympathetic to the thesis that “certain” is context- 41 sensitive does not mean I endorse preserving the view that knowledge 42 requires certainty by appeal to semantic ascent. As Unger himself noted, 43 it is perfectly in order to describe someone whose belief that p does not meet 44 the contextually salient standard of certainty as knowing that p. Knowing 45 requires neither certainty nor “certainty”. phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 Conclusion 3 4 I have defended fallibilism via the familiar strategy of arguing that there 5 is a pragmatic explanation for the data that suggests that knowing that 6 p entails being subjectively or epistemically certain that p. The problem 7 with previous attempts is that their proponents have never provided a 8 clear description of the nature of the pragmatic explanation, or a decisive 9 refutation of the explanation in terms of an entailment between knowledge 10 and certainty. The appeal to pragmatics has therefore seemed like an ad hoc 11 attempt to explain away obvious entailments. 12 I have argued that the attraction of the entailment thesis is due to an 13 insufficient diet of examples; when we cast our nets more broadly, we see it 14 cannot be correct. Furthermore, the intuitions that have been marshaled in 15 favor of the entailment thesis uniformly have the character of instances of 16 Moore’s Paradox, which are typically used as evidence in favor of various 17 norms of assertion. Following this strategy leads directly to the adoption of 18 a certainty norm for assertion. On the supposition that there is a certainty 19 norm (or norms) for assertion, we can explain all instances of Moore’s 20 Paradox, including the evidence in favor of an entailment between knowledge 21 and certainty. So not only is the entailment thesis clearly incorrect, but we 22 have in place a compelling pragmatic explanation of the data seemingly 23 supporting it, an explanation of a character familiar from both classical and 24 recent discussions of Moore’s Paradox. 25 The view of the relation between knowledge, certainty, and assertion 26 that I have defended here has a number of consequences. For example, it 27 undermines a recent argument by Keith DeRose (2002) for contextualism 28 about knowledge attributions. According to DeRose, the standards for 29 assertion vary from context to context. If the knowledge account of assertion 30 is correct, then contextualism about knowledge attributions seems to follow. 31 As DeRose writes: 32 33 What of the advocate of the knowledge account of assertion who does not 34 accept contextualism? Such a character is in serious trouble. Given invariantism 35 about knowledge, the knowledge account of assertion is an untenable attempt 36 to rest a madly swaying distinction upon a stubbornly fixed foundation. Less 37 metaphorically, it is an attempt to identify what is obviously a context-variable 38 standard (the standard for the warranted assertion of “P”) with what one 39 claims is a context-invariable standard (the relevant truth-condition of “S knows 40 that P,” according to the invariantist). The knowledge account of assertion 41 demands a contextualist account of knowledge and is simply incredible without 42 it. 43 44 Given what I have argued, one can agree with DeRose that there are 45 varying contextual standards for assertion, while rejecting contextualism phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 about knowledge attributions. Since the norms for assertion involve certainty, 3 if certainty is also a context-dependent matter, the fact that there are varying 4 contextual standards for assertion is consistent with invariantism about 5 knowledge. 6 Fallibilism in epistemology is often formulated as the doctrine that 7 knowledge is compatible with lack of certainty. It is a widespread belief 8 among philosophers that the folk concept of knowledge has an infallibilist 9 character, and fallibilism is the doctrine to which theorists of knowledge are 10 forced to retreat when confronted with its implications. One charge against 11 fallibilism has been that it seems to entail that I can know that p, despite 12 it being possible that ∼p. The other charge is that it seems to entail that I 13 can know that p, despite being less than certain that p. In previous work 14 (XXXX), I have argued that fallibilism does not entail that I can know that 15 p, despite it being possible that ∼p. In this paper, I have argued that while 16 fallibilism does entail that I can know that p despite being less than certain 17 that p, it follows from independent facts about norms for assertion that I 18 cannot say that I know that p and am less than certain that p. Therefore, no 19 revision in our ordinary conceptual scheme is required to embrace fallibilism. 20 Our folk concept of knowledge gives no succor to the skeptic. 21 22 23 Notes 24 25 1. I argue below that asserting “I know that Bill came to the party” pragmatically 26 imparts that the utterer is certain that Bill came to the party, and that it is 27 epistemically certain for the utterer that Bill came to the party. Thus, (24) and 28 (25) are similar to cases in which an implicature is reinforced, as in the example 29 “John has two children. In fact, he has exactly two children.”, or “I ate some of the cake, but I didn’t eat all of it.” Pragmatically imparted information can be 30 reinforced; entailments cannot (Sadock, 1978). Thanks to John Bengson here. 31 2. There are of course many other cases in which focus affects truth-conditions. 32 Consider, for example, the distinction in truth-conditions between “Hurricanes 33 arise in this part of the Atlantic” and “Hurricanes arise in this part of the 34 Atlantic”. The former is true if and only if at least some hurricanes arise in the 35 demonstrated portion of the Atlantic. The latter is true if and only if it is a 36 generic property of hurricanes that they arise in the demonstrated part of the 37 Atlantic. 38 3. Unger has a second argument against Dretske, involving indirect speech reports 39 (p. 79), which is undermined once one recognizes that focus is a context-sensitive 40 semantic phenomenon. 4. There is a good deal of intuitive evidence against this. Suppose I need to cut 41 through something thick, and I ask my friend for a knife, and he brings me a 42 butter-knife. I might respond by saying “I need a knife, not this thing.” 43 5. I recall learning about an example similar to this one from Brian Weatherson’s 44 weblog (http://tar.weatherson.org). 45 6. This strategy is also one Unger (Ibid.) contemplates. phis_136 phis2007.cls (1994/07/13 v1.2u Standard LaTeX document class) 7-22-2008 :809

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2 7. Alternatively, the right reaction to these cases may be to subsume the apparent 3 counterexamples to the thesis that epistemic certainty entails knowledge to cases 4 of dispositional belief. 5 8. It bears mention that the certainty norm of assertion is in tension with other 6 commitments I have incurred in my work. For example, in XXXX, one of the 7 claims we defend is that under certain conditions, knowing that p is sufficient for 8 acting on p. 9. Thanks to John Hawthorne for discussion. In unpublished work, Michael 9 Huemer has persuasively argued for a similar conclusion with respect to examples 10 such as (50). 11 10. Thanks to Michael Martin and Ian Rumfitt for discussion here. 12 13 14 References 15 16 DeRose, Keith (2002): “Assertion, Knowledge, and Context,” Philosophical Review 111: 167– 17 203. 18 DeRose, Keith (2004): “Single Scoreboard Semantics,” Philosophical Studies 119: 1–21. 19 Dretske, Fred (1972): “Contrastive Statements”, Philosophical Review, 81.4: 411–437. 20 Klein, Peter (1981): Certainty: A Refutation of Skepticism (Minnesota: University of Minnesota Press). 21 Lackey, Jennifer (forthcoming): “Norms of Assertion”, Nous. 22 Lewis, David. 1996. “Elusive knowledge” Australasian Journal of Philosophy 74: 549–567. 23 Miller, Richard (1978): “Absolute Certainty”, Mind, 87: 46–65. 24 Pryor, James (2000): “The Skeptic and the Dogmatist”, Nousˆ 34 (2000), 517–49. 25 Sadock, Jerry (1978): “On Testing for Conversational Implicature”. In Syntax and Semantics 9: Pragmatics, edited by Peter Cole: 281–297. 26 Unger, Peter (1975): Ignorance (Oxford: Oxford University Press). 27 Weiner, Matthew (2005): “Must We Know What We Say?” Philosophical Review, April 2005(vol. 28 114 no. 2). 29 Williamson, Timothy (2000): Knowledge and Its Limits (Oxford: Oxford University Press). 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45