Mentalism and Epistemic Transparency
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Defeat: If one is in an epistemic position to know that one is not in an epistemic position to know that p, then one is not in an epistemic position to justifiably believe that p (K~Kp → ~Jp) Collapse: If one is not in an epistemic position to know that p, then one is not in an epistemic position to justifiably believe that p (~Kp → ~Jp) The conclusion of the argument is that one is in an epistemic position to justifiably believe a proposition only if one is in an epistemic position to know it. Since one is in an epistemic position to know a proposition only if it is true, it follows that one is an epistemic position to justifiably believe only true propositions. Moreover, justifiably believing a proposition is a matter of taking advantage of one’s epistemic position to justifiably believe it. So, if one is in an epistemic position to justifiably believe only true propositions, then it follows that there are no justified false beliefs. A proponent of Transparency has two options: either to accept Collapse or to deny Defeat. In what follows, I will explain why neither option is available to a proponent of Williamson’s brand of knowledge-first epistemology. Moreover, I will suggest that neither option is plausible on its own terms. I begin by noting that Williamson is committed to accepting a close relative of Defeat by his claim that knowledge is the norm of assertion and belief, which he articulates in the form of the knowledge rule:
According to the knowledge rule, it is permissible to believe a proposition only if one knows it. However, it does not follow that it is reasonable, rational or justified to believe a proposition only if one knows it.16 Instead, Williamson claims that we can explain when it is reasonable to believe a proposition by appealing to the knowledge rule together with the following bridge principle:
The knowledge rule plus the bridge principle yields the following derived rule:
Thus, if it is permissible to believe a proposition only if one knows it, then it is reasonable to believe a proposition only if one has evidence that justifies believing that one knows it. As Williamson writes, “the knowledge rule for assertion corresponds to the norm that one should believe p only if one knows p. Given that norm, it is not reasonable to believe p when one knows that one does not know p.” (2000: 255-6) Williamson’s claim is further supported by examples.17 In Goldman’s (1976) example, Henry is in fake barn country, so he does not know that there is a barn ahead. But he does not know that he is in fake barn country, so it is reasonable for him to believe that there is a barn ahead. However, if Henry learns that he is in fake barn country, then it is no longer reasonable for him to believe that there is a barn ahead, since he now knows that he does not know it. Moreover, the epistemic claim of Defeat applies regardless of whatever Henry believes. If he is in an epistemic position to know that he is not in an epistemic position to know that there is a barn ahead, then he is not in an epistemic position to justifiably believe it. If Defeat is accepted, then the only remaining option is to accept Collapse. However, this is highly counterintuitive. Indeed, I will suggest below that it is worse than counterintuitive. In philosophy, of course, no position is without its defenders. For instance, Jonathan Sutton (2005) has argued that a belief is justified if and only it is knowledge. He therefore denies that there are any justified false beliefs or even Gettier cases in which justified true beliefs are not knowledge. By contrast, Williamson does not accept Collapse. For instance, Gettier cases play an important role in his argument that knowledge is a factive mental state.18 Moreover, he explicitly allows that one has justification to believe false propositions, which are made epistemically probable by true propositions that one knows.19 Williamson’s equation of evidence and knowledge does not imply that one has justification to believe only true propositions, since evidence is what justifies, rather than what is justified.20 However, it does imply that one’s evidence in the good case is different from one’s evidence in the bad case. In each case, one’s evidence includes the proposition that it seems that one has hands, but in the good case one’s evidence also includes the proposition that one has hands. One’s evidence in the good case entails that one has hands and so justifies believing that one has hands to the highest degree. By contrast, one’s evidence in the bad case does not entail, but only makes it probable that one has hands and so justifies believing that one has hands to less than the highest degree. On Williamson’s view, a belief is justified to the highest degree only if it is knowledge, but it does not follow that a belief is justified only if it is knowledge, since some beliefs are justified to less than the highest degree.21 As we have seen, Williamson does not accept Collapse. But since others do, we should consider what there is to be said against this view. It goes without saying that it is deeply counterintuitive to deny that justified beliefs can be false. But is there anything at stake here besides brute intuition? I suggest that what is at stake is the nature of an epistemic ideal. What is lost on the factive conception of epistemic transparency is the idea that there is an epistemic ideal – and a corresponding dimension of epistemic evaluation – that is distinct from both omniscience and infallibility. On the non-factive conception of epistemic transparency, the ideal epistemic subject is omniscient and infallible about only very a limited domain of facts. This includes epistemic facts about which propositions comprise her evidence and which propositions she has justification to believe. It also includes non-epistemic facts about her non-factive mental states, which determine those epistemic facts. However, the ideal epistemic agent is not omniscient or infallible about facts which extend beyond her subjective point of view on the world. This is essential for making sense of an important epistemic ideal, which captures what one ought to believe given the limitations of one’s subjective point of view on an objective world.
Epistemic transparency is central to the debate between factive and non-factive versions of mentalism about evidence. If evidence is transparent, then factive mentalism is false, since factive mental states are not transparent. Williamson defends factive mentalism by arguing that epistemic transparency is a myth, since there are no transparent conditions except trivial ones. This paper responds by drawing a distinction between epistemic and doxastic notions of transparency. Williamson’s argument succeeds in showing that no conditions are doxastically transparent, but it fails to show that no conditions are epistemically transparent. Moreover, this is sufficient to reinstate the original form of argument against factive mentalism. At this stage, one might attempt to defend factive mentalism by arguing that factive mental states are epistemically transparent, but not doxastically transparent. However, my objection is that this strategy collapses the distinction between epistemic ideals associated with knowing and justifiably believing. We should therefore deny that factive mental states are epistemically transparent. In conclusion, epistemic transparency may provide the basis of a compelling argument against factive mentalism. However, it is beyond the scope of this paper to settle the debate between factive and non-factive versions of mentalism. My aim here is to defend epistemic transparency against Williamson’s counterarguments. It is a further task to give positive arguments that evidence is epistemically transparent and that evidence is determined by non-factive mental states, which are also epistemically transparent. This is a task that I leave for another occasion.22
Alston, William (1989) Epistemic Justification: Essays in the Theory of Knowledge, Ithaca, NY: Cornell University Press. Berker, Selim (2008) “Luminosity Regained” Philosophers’ Imprint 8 (2): 1-22. Brueckner, Anthony and M. Oreste Fiocco (2002) “Williamson’s Anti-Luminosity Argument” Philosophical Studies 110: 285-93. Christensen, David (2004) Putting Logic in its Place: Formal Constraints on Rational Belief, Oxford University Press. Conee, Earl (2005) “The Comforts of Home” Philosophy and Phenomenological Research 70 (2): 444-451. Conee, Earl and Richard Feldman (2001) “Internalism Defended” American Philosophical Quarterly 38: 1-18. Feldman, Richard (2000) “The Ethics of Belief” Philosophy and Phenomenological Research 60 (3): 667-695. Goldman, Alvin (1976) “Discrimination and Perceptual Knowledge” Journal of Philosophy 73: 771-91. Goldman, Alvin (1979) “What is Justified Belief?” in (ed.) G. Pappas, Justification and Knowledge, Dordrecht: Reidel. Greenough, Patrick (ms) “Our Cognitive Homes” Hawthorne, John (2005) “Knowledge and Evidence” Philosophy and Phenomenological Research 70 (2): 452-8. McDowell, John (1995) “Knowledge and the Internal” Philosophy and Phenomenological Research 55 (4): 877-93. Neta, Ram and Guy Rohrbaugh (2004) “Luminosity and the Safety of Knowledge” Pacific Philosophical Quarterly 85: 396-406. Neta, Ram and Duncan Pritchard (2007) “McDowell and the New Evil Genius” Philosophy and Phenomenological Research 74: 381-96. Pollock, John and Joseph Cruz (1999) Contemporary Theories of Knowledge, Rowman and Littlefield. Raffman, Diana (1995) “On the Persistence of Phenomenology” in (ed.) T, Metzinger, Conscious Experience, Schoningh. Ramachandran, Murali (2009) “Anti-Luminosity: Four Unsuccessful Strategies” Australasian Journal of Philosophy 87 (4): 659-73. Reed, Baron (2006) “Shelter for the Cognitively Homeless” Synthese 148: 303-8. Smithies, Declan (forthcoming) “The Normative Role of Knowledge” Nous. Sosa, Ernest (2003) “Privileged Access” in (eds.) Q. Smith and A. Jokic, Consciousness: New Philosophical Perspectives, Oxford University Press. Sosa, Ernest (2009) “Timothy Williamson’s Knowledge and Its Limits” in (eds.) P. Greenough and D. Pritchard, Williamson on Knowledge, Oxford University Press. Sutton, Jonathan (2005) “Stick To What You Know” Nous 39 (3): 359-96. Steup, Matthias (2009) “Are Mental States Luminous?” in (eds.) P. Greenough and D. Pritchard, Williamson on Knowledge, Oxford University Press. Weatherson, Brian (2004) “Luminous Margins” Australasian Journal of Philosophy 83: 373-83. Wedgwood, Ralph (2002) “Internalism Explained” Philosophy and Phenomenological Research 65 (2): 349-69. Williamson, Timothy (1994) Vagueness, London: Routledge. Williamson, Timothy (2000) Knowledge and Its Limits, Oxford University Press. Williamson, Timothy (2005) “Replies to Commentators” Philosophy and Phenomenological Research 70 (2): 468-91. Williamson, Timothy (2008) “Why Epistemology Can’t Be Operationalized” in (ed.) Q. Smith, Epistemology: New Philosophical Essays, Oxford University Press. Williamson, Timothy (2009) “Replies to Critics” in (eds.) P. Greenough and D. Pritchard, Williamson on Knowledge, Oxford University Press. 1 Evidentialism is the thesis that one’s evidence determines which propositions one has justification to believe. If evidentialism is true, then mentalism about evidence entails mentalism about justification, the thesis that one’s mental states determine which propositions one has justification to believe. 2 The rationale for this assumption is that knowledge of epistemic truths depends on knowledge of non-epistemic truths, which determine those epistemic truths. 3 My own view is that epistemic transparency is indispensable for motivating non-factive versions of mentalism. However, Pollock and Cruz (1999), Conee and Feldman (2001) and Wedgwood (2002) argue for non-factive versions of mentalism without appealing to epistemic transparency. 4 Williamson (2000: Ch.4). My presentation draws on Weatherson (2004) and Berker (2008). 5 “One can believe that C obtains and be safe from error in doing so even if C does not safely obtain, if whether one believes is sufficiently sensitive to whether C obtains. For example, one may be safe from error in believing that the child is not falling even though she is not safe from falling, if one is in a good position to see her but not to help her.” (Williamson 2000: 127) 6 Offensive strategies are pursued by Brueckner and Fiocco (2002), Neta and Rohrbaugh (2004), Weatherson (2004), Berker (2008), Ramachandran (2009) and Steup (2009). I am not persuaded by these strategies, although I do not have the space to survey them here. 7 Defensive strategies are pursued by Hawthorne (2005), Conee (2005), Reed (2006) and Sosa (2009); see Williamson (2005) and (2009) for criticisms. These authors argue that there are some conditions C such that one is always in a position to know that C obtains if C obtains determinately, intensely, or in some other specific way. My own strategy is rather different from all of these. 8 “Margin for error principles…seem specific to knowledge. If one Фs a proposition in a situation s, one leaves a margin for error only if that proposition is true in all cases similar enough to s. Since s is certainly similar enough to itself, the proposition must be true in s. Thus if Фing requires a margin for error, one Фs only true propositions. Knowledge is such an attitude; reasonable belief is not.” (Williamson 1994: 224-5) 9 This would be accepted by some proponents of factive mentalism, if not by Williamson himself. For instance, see McDowell (1995) and the discussion in Neta and Pritchard (2007). 10 This was my own view in Smithies (2006: 84, fn.9). 11 Compare Raffman’s (1995) memory constraint: given the limitations on perceptual memory, one’s ability to perceptually recognize or reidentify a colour shade over time is less accurate than one’s ability to perceptually discriminate it from other shades at the same time. 12 “How then would one distinguish (1) an unjustified ‘introspective’ judgement, say that one’s image has 48 speckles, when it is a true judgement, and one issued in full view of the image with that specific character, from (2) a justified ‘introspective’ judgement, say that one’s image has 3 speckles? The relevant distinction is that the latter judgement is both (a) safe and (b) virtuous, or so I wish to suggest. It is ‘safe’ because in the circumstances not easily would one believe as one does without being right. It is ‘virtuous’ because one’s belief derives from a way of forming beliefs that is an intellectual virtue, one that in our normal situation for forming such beliefs would tend strongly enough to give us beliefs that are safe.” (Sosa 2003: 290) 13 Here I assume that cases in which one justifiably believes that C obtains on the basis of different evidence are not relevantly close cases. 14 Compare Goldman’s definition of ex ante justification in terms of ex post justification: “Person S is ex ante justified in believing p at t if and only if there is a reliable belief-forming operation available to S which is such that if S applied that operation to his total cognitive state at t, S would believe p at t-plus-delta (for a suitably small delta) and that belief would be ex post justified.” (1979: 21) 15 See Smithies, “Why Care About Justification?” for a more detailed discussion of epistemic idealization and its importance in the theory of justification. 16 “On this analogy between assertion and belief, the knowledge rule for assertion does not correspond to an identification of reasonable belief with knowledge. The rule makes knowledge the condition for permissible assertion, not reasonable assertion. One may reasonably do something impermissible because one reasonably but falsely believes it to be permissible.” (Williamson 2000: 256) 17 Smithies (forthcoming) uses examples like this one to motivate the JK rule, according to which one has justification to believe a proposition if and only if one has justification to believe that one is in an epistemic position to know it. For present purposes, however, we need only the ~K~K rule, according to which one has justification to believe a proposition if and only if one is not in an epistemic position to know that one is not in an epistemic position to know it. 18 See Williamson (2000: 2, 8, 30). 19 “True propositions can make a false proposition probable, as when someone is skilfully framed for a crime of which she is innocent. If perceptual evidence in the case of illusions consists of true propositions, what are they? The obvious answer is: the proposition that things appear to be that way.” (Williamson 2000: 198) 20 “Although it has been shown that what is justified need not be knowledge, even when it is true, it has not been shown that what justifies need not be knowledge.” (Williamson 2000: 185) 21 “On this view, the difference is that in the non-sceptical scenario the subject’s total evidence entails that the child is playing, whereas in the sceptical scenario the subject’s total evidence does not entail that the child is playing, although it does (misleadingly) make it probable that the child is playing. Consequently, the belief that the child is playing is more justified in the non-sceptical scenario than it is in the sceptical scenario, even though in both scenarios it has considerable justification.” (Williamson 2005: xxx) 22 Many thanks for excellent and stimulating discussions with David Chalmers, Patrick Greenough, John Maier, Nicholas Silins, Daniel Stoljar and Ralph Wedgwood. |