For Skepticism: From Antiquity to the Present, (eds.) D. Machuca & B. Reed, (London: Bloomsbury, forthcoming). DISJUNCTIVISM AND SKEPTICISM DUNCAN PRITCHARD & CHRIS RANALLI University of Edinburgh 1. THE NATURE OF PERCEPTUAL EXPERIENCE I see a particular book on the shelf. How should I characterize the nature of this visual perception? According to naïve realism, what explains what it is like for me to see this book is the book itself and its manifest properties⎯the properties that I can see, like its color, shape, size, texture, and so on. In particular, naïve realism maintains that the objects in the world around us⎯objects like trees, books, tablecloths, and so on⎯enter into our experiences of them as constituents. On this view, it is the external objects and their manifest properties which explain the "phenomenal character" of our perceptual experiences⎯what Thomas Nagel (1974) called those features of experience such that there is something that it is like to undergo them. Most philosophers reject naïve realism in favor of some form of intentionalism about the nature of experience.1 According to intentionalism, sense experience is an intentional state, like belief or thought. Consider a now famous expression of the view from Christopher Peacocke: A visual perceptual experience enjoyed by someone sitting at a desk may represent various writing implements and items of furniture as having particular spatial relations to one another and to the experiencer, and as themselves having various qualities [...] The representational content of a perceptual experience has to be given by a proposition, or set of propositions, which specifies the way the experience represents the world to be. (Peacocke 1983: 5) 2 Intentionalism thus holds that perceptual experiences have representational content⎯contents which are about something, or represent the world as being some way⎯which permits an assessment of them as successful or unsuccessful, veridical or unveridical, or true or false. When framed in the terms of the old debate between direct realism and indirect realism, both naïve realism and intentionalism are versions of direct realism because neither view maintains that there are surrogate objects or properties that we experience which mediate our perceptual experiences of mind-independent external objects and their properties. For the naïve realist, objects and properties in the world around us can enter into our experiences as constituents. Our perceptions of those objects are "direct" in the sense that those objects in part constitute our perceptual experiences when perceived. However, while the intentionalist does not characterize perceptual experience as a relation to mind-independent objects and properties, she doesn't thereby commit herself to characterizing it as a relation to other kinds of objects and properties. Instead, perceptual experience is a representational state, and just as we can believe that snow is white without the belief first being about something else distinct from snow and its whiteness, so too we can have a perceptual experience in which we represent that snow is white without the experience first being about something else distinct from snow and its whiteness. If we describe the nature of perceptual experience like this, it's not clear what could make the mental state "indirect" in any philosophically significant sense. In this way, while the naïve realist and the sense-datum theorist agree that the nature of sense experience is relational⎯experience is a relation to objects and properties⎯they disagree on the nature of what it's a relation to. And this distinction helps sharpen the difference between naïve realism and intentionalism. For the intentionalist, sense experience is not a relation to mind-independent external objects and properties, but not because it is a relation to mind-dependent objects and properties. Instead, sense experience is not a bona fide relation, in which both relata exist. So, while the naïve realist and the sense-datum theorist agree about the relational character of sensory experience, the naïve realist and the intentionalist, contra the sense-datum theorist, agree that sense experience is "direct," in the sense that we can perceive external material objects without first perceiving something else ontologically distinct from them, like sense-data. The central reason for rejecting naïve realism is some form of the argument from hallucination. As a general template, the argument can be framed as a paradox. Naïve realism appears to best articulate how perceptual experience strikes us as being on reflection. That is, it just strikes us that during visual perception, say, those objects and properties around us that we see and attend to are themselves part of the very visual perception. As P. F. Strawson (1974) once put the point, it seems like if we try to attend to the objects and properties of our experiences, we thereby 3 attend to the objects and properties in the world around us. But naïve realism is apparently shown by the argument from hallucination to be inconsistent with two other plausible theses: experiential naturalism (EN) and the common kind assumption (CKA).2 According to experiential naturalism, our sense experiences are subject to what Mike Martin (2004: 39) calls the natural "causal order" ⎯that is, are subject to causal stimulation, just like other material objects, properties, or states-of-affairs. In particular, a suitable stimulation to the brain can cause an experience in the subject which⎯at least in principle⎯is indistinguishable from a perception. Moreover, the common kind assumption claims that the kind of mental event that occurs when I perceive an external material object is a kind of event I can undergo even in the absence of the objects or properties that I perceived. Naturally, one might think that this thesis gives credence to the idea that it's possible to undergo hallucinations which are indistinguishable from veridical perceptions because such mental events are simply events of the same kind being instantiated in two different kinds of cases: one in a case where what causes the experience is a mind-independent object, the other a suitable brain-stimulation. The argument from hallucination against naïve realism then moves as follows. (CKA) implies that whatever the nature of the sense experience during perception, that kind of mental event can occur during hallucination. According to naïve realism, however, perceptual experience is a kind of mental event which is constitutively a relation, and in particular, a relation to mindindependent, external objects. From (CKA) and naïve realism alone, there is no inconsistency. But once we add the plausible (EN), (CKA) and naïve realism are rendered inconsistent. After all, naïve realism tells us that perceptual experience is constitutively relational. So by (CKA), that kind of mental event can occur in cases of hallucination. But then there must exist both relata of the sensory relation. However, (EN), together with (CKA), tells us that brain-stimulation alone is sufficient to cause a sensory experience of the kind that is instantiated during perception. But the conditions necessary to cause a hallucinatory experience are not sufficient to cause the existence of the relata, namely, the subject and the object of the subject's awareness. And, ex hypothesi, hallucinations aren't relations to anything. So, from (CKA) and (EN), naïve realism is false. Disjunctivism about the nature of sense experience can be seen as a tool for blocking the negative conclusion of this argument⎯viz., that naïve realism is false (Martin 2006: 354). According to disjunctivism, the nature of the experiences we have while veridically perceiving some object differs in kind from the nature of the experiences we have when undergoing indistinguishable hallucinations. Instead of thinking of the nature of sense experience as what is metaphysically in common between cases of veridical perception and cases which fall short of it, we can instead think 4 of the metaphysical nature of sense experience as divergent across "good" cases like veridical perception, and "bad" cases like hallucination. According to this line, there are no metaphysical commonalities between the disjoint cases of perception and hallucination from which a general theory of the nature of sensory experience can be given.3 With disjunctivism in hand, the proponent of naïve realism can respond to the argument from hallucination as follows. It is true that brain-stimulation alone can cause us to have experiences which are indistinguishable from veridical perceptions. But it does not follow from this that that kind of mental event, the indistinguishable hallucination, has the same nature as the kind we have when we veridically perceive external material objects and properties. Instead, we can characterize the visual experience as of a coffee cup, say, as either a state in which we perceive the coffee cup or as one in which it seems to us just as if we do, as when we suffer from an indistinguishable hallucination.4 In this fashion, disjunctivism allows one to maintain that the explanans of the relevant features of experiences in cases of veridical perception, such as its phenomenal character, can be external mind-independent objects and properties, even if it fails to be that in cases which fall short of veridical perception, such as hallucination and illusion. However, disjunctivism need not be understood as a view committed to naïve realism. One can be an intentionalist and accept disjunctivism. For example, one might want to characterize perceptual experience as a distinctive kind of representational state that cannot be instantiated in cases which fall short of veridical perception, such as hallucination.5 Following a view like Bertrand Russell's (1912; 1917) about the nature of our grasp of propositions, we might think that we grasp some types of propositions in virtue of being acquainted with some of the constituents of those propositions. If we add that external mind-independent objects and properties can be constituents of those kinds of propositions, and we also add that those kinds of propositions can be the content of a perceptual experience, this allows one to formulate a distinctive kind of disjunctivism about the nature of sense experience in virtue of appealing to the different kinds of representational content an experience can instantiate in cases of veridical perception, but not in cases of hallucination.6 This argument highlights how, even if naïve realism entails disjunctivism, the converse need not be true. Disjunctivism is compatible with intentionalism, at least if we take the central component of intentionalism to be the thesis that sensory experience has representational content, and it is its representational content which bears the burden of explaining the nature of sensory experience. Indeed, this helps us to further sharpen the distinction between naïve realism and intentionalism. What is central to naïve realism is the thesis that external material objects and properties, and our sensory relation to them, bear the burden of explaining the nature of sensory experience. But what is central to intentionalism is that it's the representational content of 5 experience which bears that burden, and ipso facto not that sensory experience is a relation to external material objects and properties, even if it were. Of course, one can be an intentionalist who believes that the representational content of veridical perception is a kind of content where we are acquainted with⎯and so related to⎯some of the components of the content, where some of the components of the content are external material objects and properties. But note that this kind of intentionalism obscures the distinction between naïve realism and intentionalism, and it's not clear that it doesn't simply collapse the distinction. So, whether a significant distinction between the two would remain at that point is still quite controversial and difficult to answer.7,8 2. SKEPTICISM AND DISJUNCTIVISM The epistemological problem of the external world is the problem of explaining how knowledge of the external world is possible given certain obstacles which make it look impossible. One obstacle to this kind of knowledge can be derived from a certain intuitive requirement on knowledge. For example, we might think that in order to know that p, we have to know that all of those propositions which we know to be incompatible with p are false. For example, consider the proposition that I'm a bodiless brain-in-vat, stimulated to have experiences which are indistinguishable from the corresponding veridical perceptions that I think I've had. Call this proposition (BIV). Now consider the following argument: (P1) If I know that I have hands, then I know that ~(BIV). (P2) I don't know that ~(BIV). Therefore, (C) I don't know that I have hands. The following principle can be proffered in favour of (P1): Competent Deduction Closure If S knows that p, and S competently deduces from p that q, thereby forming a belief that q on this basis while retaining her knowledge that p, then S knows that q.9 We might think that this principle⎯"closure" for short⎯just gives expression to our intuition that competent deduction from known propositions can be a means of extending our knowledge to the known consequences of those propositions. Since we know that having hands implies that we are not bodiless, and so not bodiless brains-in-vats, the closure principle implies that if we do know that we have hands, then we can know that ~(BIV). But ~(BIV) seems to be just the sort of proposition 6 we cannot know to be true. After all, how could I know that I'm not a bodiless brain-in-a-vat if being the victim of that kind of scenario would produce in me just the sorts of experiences I would have were I an embodied human being, active in the familiar world around us? This makes it look like I don't know that ~(BIV). But this together with (P1) entails that I don't know that I have hands, which is counterintuitive. How disjunctivism fares against this problem depends on how we understand the skeptical challenge. For example, if we frame the problem of the external world as arising out of the supposed fact that sense-experience underdetermines the choice between various propositions about the world around us and (known to be incompatible) competitor propositions, then disjunctivism about the nature of sense experience might be able to provide a response to this challenge. If we conceive of the nature of sense experience in general as disjunctive⎯as dividing into states in which either we perceive external material objects, or states in which we seem to do so but fail (as with indistinguishable hallucinations)⎯then why couldn't some sense experiences put us in a position to know propositions about the world around us, and so put us in a position to infer that ~(BIV) from our knowledge that those propositions are true, even if our capacity to do so is fallible? Call this the simple disjunctivist response. An immediate problem for the simple disjunctivist response is that it's not at all clear that a core component of the problem of the external world depends on a view about the relation between sense experience and the external world.10 Moreover, even if it is a core component of the problem, it's not clear that mounting a competing thesis is sufficient to remove the challenge. After all, certain arguments make it look plausible that sense experience underdetermines the choice between propositions about the world and their corresponding skeptical competitors. The disjunctivist would have to speak to these arguments.11 Another concern is that the disjunctivist about sense experience just misses the point that the problem of the external world is an epistemological problem, arising out of core epistemological intuitions. For example, (BIV) might express a scenario where the subject is not perceiving the world around her for how it is (since she's a bodiless brain-in-a-vat, even though it doesn't seem to her that she is). But what is at issue with (BIV) is not the fact that she cannot perceive the world around her for how it is, but that whether or not (BIV) is true, it's not clear that we could come to know that ~(BIV). The reason need not be that the kinds of experiences we have in either case are experiences of the same nature. Instead, it can be that we cannot distinguish between cases in which we do get things right from cases in which we seem to get things right, but nevertheless fail. For example, one might argue in support of the following principle, which we will call perceptual discrimination: Perceptual Discrimination (PD) 7 If S knows that p on the basis of perceptual experience, then S can discriminate cases in which p from cases in which ~p. For example, if I know that a goldfinch is in the garden on the basis of visual experience, then I must be able to discriminate the case where it's a goldfinch in the garden from other kinds of birds being in the garden. If not, what makes it the case that the visual experience supplies me with the knowledge that it's a goldfinch rather than some other bird, or something less specific like that a bird is in the garden? With (PD), there is a quick move available to (P2) (i.e., ~K~(BIV)). After all, I cannot discriminate cases in which I see hands from cases in which I am a bodiless brain-in-a-vat who seems to see hands.12 Moreover, we can leave (PD) to one side and just consider the closure principle. This latter principle seems to reflect a general epistemological intuition, and it implies that if we know propositions about the world around us, such as that we have hands, then we can know ~(BIV), at least provided we make the competent deduction. But we might just take it as primitive that we don't know that ~(BIV). It might just reflect a basic epistemological intuition: an intuition as basic as that not all propositions can be known. If this is right, then the proponent of the simple disjunctivist response will need to explain why it isn't primitive, even if initially it strikes us as being primitive. How might the proponent of the simple disjunctivist response overcome this challenge? One thought is that she should speak directly to epistemological concerns. For example, she could say that our perceptual relation to mind-independent external objects is sufficient for knowledgelevel justification: justification which, if we have it, would put us in a position to know. After all, what else could be better reason for believing that I have hands than just my hands themselves being part of the very sensory episode that I enjoy? But why is disjunctivism in any better off than, say, its intentionalist rival in arguing that perceptions provide us with knowledge-level justification? More generally, there is a strong intuition in favor of the idea that there's nothing about the "directness" of a sensory perception that makes it any better a candidate for knowledge-level justification than a matching hallucination. The thought here finds a clear expression in these remarks by Earl Conee: It remains strongly intuitive that perception does not provide any better reason for an external world belief than would be provided by a matching hallucination. There is no a priori limit on the potential verisimilitude of hallucination. Whether S1 is in perceptual state P1 or the matching hallucination H1, it appears to S1 exactly as though T1 is true. Intuitively, that is as good a basis for reasonable belief in T1 as is the veridical perception. Thus, since the strength of epistemic justification is equal to the strength of reasonableness, a perception does not justify more strongly than does a matching hallucination. (Conee 2007: 18) 8 Like the previous criticism, this criticism challenges the epistemological benefits of the disjunctive conception of sensory experience. It says that even if the sensory experiences implicated in perception and hallucination are metaphysically different kinds of states, what remains epistemologically problematic is the fact that we cannot introspectively distinguish them. Notice that this challenge appeals to the following intuitive principle, which we will christen same epistemic status: Same Epistemic Status (SES) If a perceptual state E provides S with an epistemic standing for her belief that p, then any perceptual state R which is (for S) introspectively indistinguishable from E provides at least as much of an epistemic standing for S to believe that p. If we accept (SES), then the epistemological benefits of the disjunctive conception of sensory experience dissipate. 3. EPISTEMOLOGICAL DISJUNCTIVISM Let us now consider a distinctively epistemological form of disjunctivism, which we will refer to as epistemological disjunctivism. Like its metaphysical counterpart, epistemological disjunctivism is composed of a negative thesis about the fundamental difference in epistemic significance between successful and unsuccessful cases of sensory experience and a positive thesis about the nature of the epistemic significance of the sensory experience in the successful case. Epistemological disjunctivism's negative thesis consists of its rejection of (SES), which we just encountered. In particular, epistemological disjunctivists will contend that in pairings of introspectively indistinguishable good and bad cases, the subject concerned has a much stronger epistemic standing for her belief in the good case than in the bad case. (SES) can look appealing because, given that good and bad cases are indistinguishable, it is hard to fathom how the epistemic standing of one's belief in the good case could be better than the epistemic standing of one's belief in the corresponding bad case.13 Nonetheless, epistemological disjunctivism rejects this thesis. In particular, it argues that we should not limit the epistemic support available for our beliefs to the low level of epistemic support which is available in the bad case. Instead, we should regard the epistemic standing of one's belief in the corresponding good case as being far superior.14 In specifying that the epistemic support is different in the two cases, however, this still leaves open a number of options in terms of what constitutes this difference. For example, is the difference between the subject's epistemic standing in the good case and the bad case one of kind or 9 only of degree? Either way, what is crucial to epistemological disjunctivism is the idea that there is epistemic support available to one in the good case that's unavailable in the bad case. Call this the core epistemological disjunctivist thesis. It is an interesting question how metaphysical and epistemological disjunctivism relate to one another. They are certainly dialectically affiliated in the sense that, if one endorses metaphysical disjunctivism, then one will be naturally inclined to also endorse epistemological disjunctivism, and vice versa. But whether they actually entail one another is a different matter. In particular, it seems at least possible to hold the one thesis while rejecting the other, even though such a combination of views may well be philosophically quite uncomfortable.15 It should be clear that epistemological disjunctivism's prospects for dealing with the problem of radical skepticism are more promising than metaphysical disjunctivism. Recall that one core issue facing the latter proposal was that it was attempting to confront an epistemological problem and yet its own epistemological ramifications were moot. For epistemological disjunctivism, there is no such difficulty. In particular, by rejecting (SES) epistemological disjunctivism directly challenges a claim which seems to be presupposed in the radical skeptical problem. Radical skeptical scenarios, after all, are extreme examples of bad cases. And yet part of what is motivating the skeptical thought that we are unable to rule out such scenarios is that our epistemic standing in the good case is no better than it would be in a corresponding radical skeptical scenario (on account of the latter being indistinguishable from the former). Once we have rejected (SES), however, then what would prompt us to concede this point to the skeptic? Why not instead insist that so long as one is in the good case, then one's epistemic support is substantially greater than it is in the skeptical bad case, and hence that one has an epistemic basis on which one can reject this error-possibility? Whether such a line of argument is tenable will to a large extent depend on the positive thesis that the epistemological disjunctivist offers about the nature of the epistemic support in the good case. In particular, the problem facing epistemological disjunctivism on this score is that if the positive account is cast along epistemic externalist lines then the view becomes pedestrian, while if it is cast along epistemic internalist lines the view will strike many as absurd. Consider first an epistemic externalist rendering of epistemological disjunctivism, whereby the different epistemic standing of the subject's belief in the pairs of good and bad cases are not reflectively accessible to the subject.16 Such a view would be pedestrian because it is entirely normal for epistemic externalists to hold that a subject's epistemic standing differs across good and bad cases in this way. After all, on epistemic externalist views the epistemic standing of one's beliefs is dependent on non-reflectively accessible factors, such as the reliability of the belief-forming process through which one acquired one's belief. Hence it is unsurprising that in the bad cases, where those 10 externalist factors do not obtain, the subject's epistemic standing will tend to be much worse than it is in the corresponding good case. A further upshot of the foregoing is that an epistemological disjunctivism which is wedded to epistemic externalism will offer a response to the problem of radical skepticism which is no more plausible than the standard epistemic externalist responses which many find unpersuasive.17 In particular, the normal epistemic externalist line on radical skepticism is to treat our knowing as being in a sense contingent on factors beyond our ken. That is, while the skeptic insists that knowledge is (for the most part anyway) impossible, the epistemic externalist anti-skeptic argues that knowledge is possible, just so long as we are in the right kind of conditions which would sustain it. Whether we are in such conditions, however, is not held to be something that we can determine by reflecting on the nature of our epistemic position, since these conditions concern facts about the world such as whether we are indeed reliably forming our beliefs (as opposed to being a brain-in-a-vat who merely thinks that she is). The combination of epistemological disjunctivism and epistemic externalism is no different on this score. If we are indeed in the good case rather than the bad, then we are in the market for knowledge, contra the skeptic. But whether we are in the good case depends on factors outwith our reflective ken.18 Hence, if epistemological disjunctivism is to offer anything distinctive to the contemporary debate about radical skepticism, then it will need to be cast along epistemic internalist lines. Such a view would hold that the superior epistemic standing available to the subject's belief in the good case is reflectively accessible to the subject. One can straight away see a difficulty looming for this approach, which is why it is thought unattractive (indeed, simply unavailable). For given that pairs of good and bad cases are by definition introspectively indistinguishable to the agent, then how can it be that in the good case one's superior epistemic standing is reflectively accessible? We will examine this issue by looking at a particular version of epistemological disjunctivism which is cast along epistemic internalist lines. This is the approach offered by John McDowell (e.g., 1995) and, following him, Duncan Pritchard (e.g., 2012a).19 On this view, one's perceptual knowledge can consist, in paradigmatic cases at least, in one's possession of rational support that is both reflectively accessible and factive. More specifically, in such cases one perceptually knows that p in virtue of seeing that p, where that one sees that p is one's reflectively accessible rational support for believing that p. On this form of epistemological disjunctivism we thus get a particularly strong rendering of the epistemic standing of the subject's belief in the good case, in that it is an epistemic standing which actually entails the truth of the believed proposition. Clearly this is an epistemic standing 11 which is unavailable to the subject in the bad case, since as bad cases are usually described the target belief is false.20 This form of epistemological disjunctivism is distinctive in another respect too, in that the very idea that there can be factive yet reflectively accessible reasons of this kind is thought highly controversial. The claim that knowledge consists of the possession of reflectively accessible rational support marks the view out as a kind of epistemic internalism.21 But, on standard forms of epistemic internalism, the facts to which one has such special epistemic access are by their nature not such that they entail specific claims about the subject's environment (but rather concern, for example, the subject's mental states, narrowly understood). In contrast, whereas epistemic externalism does allow that knowledge can be in virtue of an epistemic standing which entails specific facts about the subject's environment, these facts (such as facts about the reliability of the process through which the subject acquired her belief) are not held to be reflectively accessible to the subject. By allowing that one's epistemic standing can be both reflectively accessible and also entail specific facts about one's environment, this form of epistemological disjunctivism is thus a highly non-standard version of epistemic internalism. Is this view tenable? We noted above that there is at least a strong prima facie reason for thinking not. For how is one to square this form of epistemological disjunctivism with the claim that pairs of good and bad cases are introspectively indistinguishable to the subject? On this view, in the good case one's rational support for believing that p can be that one sees that p, where it is reflectively accessible to one that one has this rational support. But if there are facts reflectively accessible to the subject which are only available in the good case (and the subject is in a position to know that this is so on purely a priori grounds), then surely the subject can through an entirely reflective process come to know that she is in the good case as opposed to the bad case. Isn't that in direct conflict with the stipulation that pairs of good and bad cases are introspectively indistinguishable?22 There is a further, but related, problem in play here. For consider our subject's perceptual knowledge that there is a table before her in virtue of her possession of the relevant factive reason. Given that this rational support is reflectively accessible, and given that the subject is also presumably in a position to know on a purely a priori basis that this rational support is factive, then what is to stop the subject acquiring a completely non-empirical route to the knowledge that there is a table before her? But that seems absurd. How can it be possible to come to know specific facts about one's environment through purely reflective processes?23 Let us grant for the sake of argument that these problems can be satisfactorily resolved and consider how the distinctive approach epistemological disjunctivism, so understood, offers us for 12 the problem of radical skepticism.24 On this view it is not just that one's belief has a better epistemic standing in the good case than it does in the (skeptical) bad case. Rather, one's belief in the good case has an epistemic standing which is factive (i.e., which entails the truth of the proposition believed) and which is also reflectively accessible to the subject. It follows that the subject has excellent⎯indeed, decisive⎯rational grounds available to her to prefer her everyday beliefs to radical skeptical alternatives. Hence, this version of epistemological disjunctivism can take a broadly "Moorean" line with radical skepticism and insist that we can know the denials of radical skeptical hypotheses after all. Moreover, this view can diagnose the enduring attraction of radical skepticism as being due to our having implicit philosophical commitments to such theses as (SES), theses which the epistemological disjunctivist argues we should jettison.25 One concern with this way of dealing with the problem of radical skepticism is that it can strike one as too strong. On this view, for example, it seems somewhat mysterious that the problem of radical skepticism has had such a hold on the philosophical imagination for so long. Doesn't the radical skeptic succeed in highlighting anything important about the human epistemic condition? Moreover, given the difficulties which plague epistemological disjunctivism on this construal⎯problems which we have set to one side for now⎯this response to radical skepticism has an essentially contingent status. This inevitably diminishes somewhat the intellectual comfort that might be offered by this way of responding to radical skepticism.26,27 13 REFERENCES Brewer, B. 2007. "Perception and its Objects," Philosophical Studies 132: 87-97. ⎯⎯ 2011. Perception and its Objects. Oxford: Oxford University Press. Brogaard, B. 2010. "Disjunctivism," Oxford Bibliographies: Philosophy, DOI: 10.1093/OBO/9780195396577-0033. Brueckner, A. 2010. "¬K¬SK," in his Essays on Skepticism, 367-81, Oxford: Oxford University Press. Byrne, A., & Logue, H. 2008. "Either/Or," Disjunctivism: Perception, Action, Knowledge, (eds.) A. Haddock & F. Macpherson, 57–94, Oxford: Oxford University Press. -- 2009. "Introduction," Disjunctivism: Contemporary Readings, (eds.) A. Byrne & H. Logue, vii-xxix, Cambridge, MA: MIT Press. Campbell, J. 2002. Reference and Consciousness. Oxford: Oxford University Press. ⎯⎯ 2011. "Relational versus Kantian Responses to Berkeley's Puzzle," Perception, Causation, and Objectivity, (eds.) J. Roessler, H. Lerman & N. Eilan, 35-50, Oxford: Oxford University Press. Conee, E. 2007. "Disjunctivism and Anti-Skepticism," Philosophical Issues 17: 16-36. Dorsch, F. 2011. "The Diversity of Disjunctivism," European Journal of Philosophy 19: 304-14. Fish, W. 2009a. "Disjunctivism," Internet Encyclopaedia of Philosophy, (eds.) B. Dowden & J. Fieser, http://www.iep.utm.edu/d/disjunct.htm. ⎯⎯ 2009b. Perception, Hallucination, and Illusion, Oxford: Oxford University Press. Grice, H. P. 1961. "The Causal Theory of Perception," Proceedings of the Aristotelian Society (suppl. vol.) 35: 121–52. Haddock, A., & Macpherson, F. 2008. "Introduction: Varieties of Disjunctivism," Disjunctivism: Perception, Action, Knowledge, (eds.) A. Haddock & F. Macpherson, 1-24, Oxford: Oxford University Press. Hawthorne 2005. "The Case for Closure," Contemporary Debates in Epistemology, (eds.) E. Sosa & M. Steup, 26-43, Oxford: Blackwell. Lehrer, K., & Cohen, S. 1983. "Justification, Truth, and Coherence," Synthese 55: 191-207. Littlejohn, C. 2009. "The New Evil Demon Problem," Internet Encyclopaedia of Philosophy, (eds.) B. Dowden & J. Fieser, www.iep.utm.edu/evil-new/. Martin, M. G. F. 1997. "The Reality of Appearances," Thought and Ontology, (ed.) M. Sainsbury, 77-96, Milan: Franco Angeli. ____ 2002. "Transparency of Experience," Mind & Language 17, 376–425. ⎯⎯ 2004. "The Limits of Self-Awareness," Philosophical Studies 120: 37–89. ⎯⎯ 2006. "On Being Alienated," Perceptual Experience, (eds.) T. S. Gendler & J. Hawthorne, 354-410, Oxford: Oxford University Press. McDowell, J. 1982. "Criteria, Defeasibility and Knowledge," Proceedings of the British Academy 68: 455–79. ⎯⎯ 1986. "Singular Thought and the Extent of Inner Space", Subject, Thought and Context, (eds.) P. Pettit & J. McDowell, 137-68, Oxford: Clarendon Press. -- 1994a. "Knowledge by Hearsay," Knowing from Words: Western and Indian Philosophical Analysis of Understanding and Testimony, (eds.) B. K. Matilal & A. Chakrabarti, 195-224, Dordrecht, Holland: Kluwer. ⎯⎯ 1994b. Mind and World. Cambridge, MA: Harvard University Press. ⎯⎯ 1995. "Knowledge and the Internal," Philosophy and Phenomenological Research 55: 87793. ⎯⎯ 2002a. "Knowledge and the Internal Revisited," Philosophy and Phenomenological Research 64: 97-105. 14 ⎯⎯ 2002b. "Responses," Reading McDowell: On Mind and World, (ed.) N. H. Smith, Routledge, London. ⎯⎯ 2008. "The Disjunctive Conception of Experience as Material for a Transcendental Argument," Disjunctivism: Perception, Action, Knowledge, (eds.) A. Haddock & F. Macpherson, 376-89, Oxford: Oxford University Press. ⎯⎯ 2011. Perception as a Capacity for Knowledge. Milwaukee WI: Marquette University Press. McKinsey, M. 1991. "Anti-Individualism and Privileged Access," Analysis 51: 9-16. Millar, A. 2007. "What the Disjunctivist is Right About", Philosophy and Phenomenological Research 74: 176–98. ⎯⎯ 2008. "Perceptual-Recognitional Abilities and Perceptual Knowledge," Disjunctivism: Perception, Action, Knowledge, (eds.) A. Haddock & F. Macpherson, 330-47, Oxford: Oxford University Press. Nagel, T. 1974. "What is it Like to be a Bat?," Philosophical Review 83: 435-50. Neta, R., & Pritchard, D. H. 2007. "McDowell and the New Evil Genius," Philosophy and Phenomenological Research 74: 381-96. Peacocke, C. 1983. Sense and Content: Experience, Thought and Their Relations. Oxford: Oxford University Press. Pritchard, D. H. 2007. "How to be a Neo-Moorean," Internalism and Externalism in Semantics and Epistemology, (ed.) S. Goldberg, 68-99, Oxford: Oxford University Press. ⎯⎯ 2008. "McDowellian Neo-Mooreanism," Disjunctivism: Perception, Action, Knowledge, (eds.) A. Haddock & F. Macpherson, 283-310, Oxford: Oxford University Press. ⎯⎯ 2009. "Wright Contra McDowell on Perceptual Knowledge and Scepticism," Synthese 171: 467-79. ⎯⎯ 2010. "Relevant Alternatives, Perceptual Knowledge and Discrimination," Noûs 44: 245-68. ⎯⎯ 2011a. "Epistemological Disjunctivism and the Basis Problem," Philosophical Issues 21: 434-55. ⎯⎯ 2011b. "Evidentialism, Internalism, Disjunctivism," Evidentialism and its Discontents, (ed.) T. Dougherty, 362-92, Oxford: Oxford University Press. ⎯⎯ 2012. Epistemological Disjunctivism. Oxford: Oxford University Press. ⎯⎯ Forthcoming. Epistemic Angst: Radical Scepticism and the Groundlessness of Our Believing. Princeton, NJ: Princeton University Press. Ranalli, C. Forthcoming. "Luck, Propositional Perception, and the Entailment Thesis," Synthese. Robinson, H. 2012. "Relationalism versus Representationalism: How Deep is the Divide?," Philosophical Quarterly 62, 614-19. Russell, B. 1910. "Knowledge by Acquaintance and Knowledge by Description," Proceedings of the Aristotelian Society 11: 108-28. ⎯⎯ 1912. The Problems of Philosophy. London: Home University Library. Schönbaumsfeld, G. 2013. "McDowellian Neo-Mooreanism?," International Journal for the Study of Skepticism 3: 202-17. Snowdon, P. 1990. "The Objects of Perceptual Experience," Proceedings of the Aristotelian Society (suppl. vol.) 64: 121–50. ⎯⎯ 2005. "The Formulation of Disjunctivism: A Response to Fish," Proceedings of the Aristotelian Society 105, 129–41. Soteriou, M. 2009. "The Disjunctive Theory of Perception," Stanford Encyclopaedia of Philosophy, (ed.) E. Zalta, http://plato.stanford.edu/entries/perception-disjunctive/. Strawson, P. F. 1974. "Causation in Perception," in his Freedom and Resentment, 73-93, London: Methuen. Stroud. B. 1989. "Understanding Human Knowledge in General," Knowledge and Skepticism, (eds.) M. Clay & K. Lehrer, 31-50, Boulder, CO: Westview Press. 15 ⎯⎯ 1994. "Scepticism, 'Externalism', and the Goal of Epistemology," Proceedings of the Aristotelian Society (suppl. vol.) 68: 291-307. Vahid, H. 2011. "Externalism/Internalism," Routledge Companion to Epistemology, (eds.) S. Bernecker & D. H. Pritchard, 144-55, London: Routledge. Williamson, T. 2000. "Scepticism and Evidence," Philosophy and Phenomenological Research 60: 613-28. Wright, C. 2008. "Comments on McDowell's 'The Disjunctive Conception of Experience as Material for a Transcendental Argument,'" Disjunctivism: Perception, Action, Knowledge, (eds.) A. Haddock & F. Macpherson, 390-404, Oxford: Oxford University Press. 16 NOTES 1 Although support for naïve realism has grown. See Snowdon (1990), Campbell (2002; 2011), Martin (2004; 2006), Brewer (2007; 2011), and Fish (2009b). 2 This is how Martin (2004; 2006) formulates the argument from hallucination. 3 Note that the disjunctivist is not claiming that no theory of the nature of sensory experience can be given. Instead, she is claiming that no theory of the nature of sensory experience can be given which appeals to what is metaphysically common between perception and hallucination. Instead, she might recommend that the nature of sensory experience in general should be explained epistemologically: as our inability to know introspectively a perception from a metaphysically different kind of state. See Martin (2004) for an expression of this kind of theory. 4 Put another way, we might say that cases of hallucination that are indistinguishable from veridical perception are states in which we are not only mislead about how the world is, but about how we are experientially: introspectively, we are apt to judge that we enjoy a veridical perception of some object, when in fact we suffer a mere appearance of a veridical perception of some object. See McDowell (2008) for this way of characterizing the relationship between hallucination and introspective knowledge. 5 See Martin (2002, 395n). 6 Cf. Martin (1997). 7 For recent work on whether the distinction is as deep as some philosophers of perception seem to suggest, see Brewer (2011) and Robinson (2012). 8 For some useful recent overviews of the literature on disjunctivism, see Haddock & Macpherson (2009), Byrne & Logue (2009), Fish (2009a), Soteriou (2009), Brogaard (2010), and Dorsch (2011). 9 This is essentially the formulation of the closure principle put forward by Williamson (2000a, 117) and Hawthorne (2005, 29). 10 See Wright (2008) in particular for this view. 11 One might feel that this objection turns on the debate between the disjunctivist response to the argument from hallucination and illusion, and its rivals. After all, the disjunctivist will say that what makes it look like sense experience in general underdetermines the truth-value of propositions about the external world is an argument from hallucination/illusion, blocking the support for the thesis that compelling arguments establish that sense experiences underdetermines the truth-value of those kinds of propositions. 12 See Pritchard (2010; 2012, part two) for further discussion of discrimination-style principles like (PD) and their role in an account of perceptual knowledge. 13 We are in effect here motivating (SES) by appeal to the so-called "new evil genius" thesis⎯roughly, that one has the same extent of epistemic support for one's beliefs that one's envatted counterpart enjoys for her beliefs. This is meant to be a core epistemological intuition that all epistemological theories must either accommodate or explain away. Epistemological disjunctivists opt for the latter horn⎯see, for example, Neta & Pritchard (2007) and Pritchard (2012, passim). The locus classicus for discussions of the new evil genius thesis is Lehrer & Cohen (1983). For an excellent survey of recent work on this topic, see Littlejohn (2009). 14 As McDowell (e.g., 1995) famously tends to put the point: we should reject a "highest common factor" conception of epistemic standing such that the epistemic standing enjoyed by one's beliefs in the good case is no better than that available for one's beliefs in the corresponding bad case. See Pritchard (2012, part one) for an elaboration of McDowell's argument. 15 Various commentators have argued that epistemological disjunctivism does not in itself entail metaphysical disjunctivism. See, for example, Snowdon (2005), Millar (2007; 2008), Byrne & Logue (2008), McDowell (2008, 382n), and Pritchard (2008). In particular, the claim in this regard is often that epistemological disjunctivism is compatible with a causal theory of perceptual experience, as defended, for example, by Grice (1961) and Strawson (1974). For further discussion of the logical connections between metaphysical and epistemological disjunctivism, see Haddock & Macpherson (2008), Byrne & Logue (2009), Fish (2009a), Soteriou (2009, esp. §2.4), and Pritchard (2012, part one). 16 Note that we are here casting the epistemic externalism/internalism distinction along broadly accessibilist lines. That is, roughly, we are understanding an internalist epistemic condition such that its obtaining should be reflectively accessible to the subject, and hence treating an externalist epistemic condition such that it is not reflectively accessible to the subject. Although this is a fairly standard way of understanding the epistemic externalism/internalism distinction, it is far from being uncontroversial. This way of construing the distinction should suffice for our purposes, however. For a useful recent overview of the epistemic externalism/internalism distinction, see Vahid (2011). 17 See Stroud (1989; 1994) for a subtle articulation of this kind of concern regarding standard epistemic externalist responses to radical skepticism. 18 For a variety of epistemological disjunctivism of an epistemic externalist stripe which is not pedestrian, see Williamson (2000), though note that he does not himself describe his view as being a variety of epistemological disjunctivism. What distinguishes this view from standard epistemic externalist proposals in this regard is that it is wedded to some further distinctive philosophical claims, such as that knowledge is a mental state. See Pritchard (2011b) for more on this point. Interestingly, some commentators, such as Brueckner (2010), explicitly run together the 17 McDowellian-style epistemological disjunctivism put forward by Pritchard (e.g., 2012) and the kind of position defended by Williamson. 19 See also McDowell (1982; 1986; 1994a; 1994b; 1995; 2002a; 2008; 2011) and Pritchard (2007; 2008; 2009; 2011a; 2011b). 20 Note that we are glossing over some of the nuances regarding the good/bad case distinction which are relevant to at least Pritchard's rendering of this form of epistemological disjunctivism. See Pritchard (2012, part one) for more details. We are also side-stepping the issue of what the subject's epistemic standing is in the bad case on this view. What is salient for our purposes is just that it falls well short of the factive rational support available to the subject in the good case. 21 Of an accessibilist variety at least (see note 17). See Neta & Pritchard (2007) and Pritchard (2011a; 2012, part one) for further discussion of how this form of epistemological disjunctivism should be understood in relation to the epistemic externalism/internalism distinction. 22 For a more extensive discussion of this difficulty, which he refers to as the "distinguishability problem," see Pritchard (2012, part one). 23 For a more extensive discussion of this difficulty, which he refers to as the "access problem," see Pritchard (2012, part one). The problem in play here is structurally akin to the so-called McKinsey problem which is held to afflict the combination of (some forms of) content externalism and first-person authority. See McKinsey (1991). 24 Pritchard (2011a; 2012, passim) claims that these problems⎯along with a third problem, which he refers to as the "basis problem"⎯can be resolved. Note that the basis problem turns on an issue which we haven't explored here⎯viz., whether seeing that p is a way of knowing that p. See Ranalli (forthcoming) for a discussion of the issues in this regard. 25 See Pritchard (2008; 2009; 2012, part three) for a development of this way of exploiting epistemological disjunctivism to deal with the problem of radical skepticism. For a critical appraisal of this proposal, see Schönbaumsfeld (2013). 26 In more recent work, Pritchard (forthcoming) has argued that epistemological disjunctivism of this variety should only be thought of as applying to that variety of radical skepticism which trades on the claim that the rational support we have for our beliefs is underdetermined with respect to radical skeptical scenarios. 27 This paper was written as part of the AHRC-funded "Extended Knowledge" project which is hosted by the University of Edinburgh's Eidyn Philosophical Research Centre, and we are grateful to the AHRC for their support of this research. Thanks also to Baron Reed for detailed comments on an earlier version of this paper.