teorema Vol. XXIX/1, 2010, pp. 00-00 [BIBLID 0210-1602 (2010) 29:1 ; pp. 00-00] 1 The Non-Conjunctive Nature of Disjunctivism Alessandra Tanesini Disjunctivism: contemporary readings, ALEX BYRNE & HEATHER LOGUE (EDS.), CAMBRIDGE, MA, & LONDON, MIT PRESS, 2009, pp. 368, $36.00 / £23.95 (paper), $70.00 / £45.95 (cloth). Disjunctivism: perception, action and knowledge, ADRIAN HADDOCK & FIONA MACPHERSON (EDS.),OXFORD, OXFORD UNIVERSITY PRESS, 2008, pp. 432, £63.00. The family of views known as disjunctivism first emerged in the philosophy of perception as an alternative to the causal theory. These views are the subject of intense contemporary debate, and the essays collected in these two volumes offer some of their best articulations and criticisms . As Alex Byrne and Heather Logue suggest in their introduction to the collection they have edited, the two volumes are best thought as complementing each other. The collection by Byrne and Logue, Disjunctivism: Contemporary Readings (hereafter DCR) aims to bring together some of the most important essays, and book selections, previously published elsewhere. The volume edited by Adrian Haddock and Fiona Macpherson, Disjunctivism: Perception, Action, Knowledge (hereafter PAK) includes almost exclusively new material by both prominent defenders and critics of disjunctivism (only the contribution by John McDowell had been previously published, in this very journal). The standard of all contributions is generally very high, and there is no doubt that these books are essential reading for anybody interested in the philosophy of perception. So what is disjunctivism? It is not easily characterised as one thing, and here may lie one reason why the introductions to both volumes are dedicated to the taxonomy and clarification of the numerous and different views that are referred to by the label. One of the factors which explains the difficulty with providing a crisp definition of disjunctivism is that this approach can be found in three different areas of philosophy, whilst indicating something different in each. A further source of difficulty is the fact that within one of these areas – the philosophy of perception – disjunctivism has taken numerous non equivalent forms. Given these complexities and since it is impossible 2 Alessandra Tanesini in a short critical notice to give the necessary space and attention to every contribution in these volumes, in this piece I propose to consider the main disjunctivist positions in the philosophy of perception, epistemology and the philosophy of action. These are the three areas in which disjunctivism has emerged and work by exponents and critics of these positions is well represented in these volumes. As a result of the survey I present here, I hope that it will become obvious that disjunctivism is not one thing, and that its prospects differ in different areas. A. THE PHILOSOPHY OF PERCEPTION When disjunctivism first emerged it was thought as an alternative to the causal theory in the philosophy of perception. Its early exponents were J. M. Hinton and Paul Snowdon. Selections from their pioneering work are wellrepresented in DCR, whilst PAK includes a useful piece by Snowdon on Hinton's views. The causal theory of perception offers, what seemed in the 1970s, an overwhelmingly convincing account of the necessary conditions for perceiving an object. The theory states that the object of a perception must be the cause of the ensuing perceptual experience. It is thus able to explain why, for example, I cannot be said to see a rose, which is in front of me, when I have the experience of seeming to see a rose but there is a hologram of the rose between me and the flower. Both Hinton and Snowdon treat the causal theory as offering a conceptual analysis of perceiving, seeing, hearing and so forth. They also both attack the account of the nature of experience which they think is presupposed by the causal theory. In their view the causal theory presupposes that the perceiver has experiences of the same mental kind when she is seeing an object and when she is undergoing an hallucination which she cannot by reflective introspection alone tell apart from the case of genuine perception. The causal theory explains the difference between the two cases by way of reference to the presence in the veridical case of an extra -mental factor involving the existence of an appropriate causal chain from the object of perception to the experience. Both Hinton and Snowdon point out that the assumption that the perceiver can have experiences of the same kind, when perceiving and when hallucinating, is unwarranted. Just because the perceiver cannot tell them apart it does not follow that the experiences are not different. Snowdon deploys this argument to show that the causal theory of perception if correct is an empirical, rather than conceptual, truth about perception. Hinton goes further. He commits himself to the view that perceptions and hallucinations always involve experiences of different kinds. More specifically, Hinton argues that statements such as 'It looks as if there is a rose in front of me', where 'looks' is understood phenomenologically rather than epistemically, are not reports of a single mental state (an inner experience) 3 The Non-Conjunctive Nature of Disjunctivism common between perceptions and matching hallucination. Instead, these statements are shorthand for disjunctions such as 'Either I see that there is a rose in front of me (which looks like a rose) or I am having a perfect illusion of seeing a rose'. Obviously, the equivalence of look-statements to these disjunctions can be accepted by everybody. What would distinguish the disjunctivist is the claim that perceptions and hallucinations involve experiences of different kinds. This, however, is not quite right. Because this claim also can be accepted by many who would not think of themselves as disjunctivists. One way of fleshing out this idea that the good veridical and the bad hallucinatory or perhaps illusory cases involve mental states of different kinds is to think of mental kinds as typed by their representational content, and claim that the representational content of the good case is objectdependent. However, when the idea that the good and the bad cases involve different experiences is developed in this way, it becomes apparent that this commitment is shared by those externalists who think that the representational contents of perceptual experiences are object-dependent. In other words, it becomes apparent that the claim about different kinds of experience is not sufficient to distinguish disjunctivists from their opponents. The disjunctivist claim, therefore needs to be stronger, its supporter will have to say that there is no common ele ment whatsoever between the veridical and the hallucinatory experience. Hence, as Byrne and Logue make abundantly clear in 'Either/Or' (in PAK) a moderate view of experience is available. Its supporters deny that experiences are purely inner, but unlike disjunctivists , they claim that experiences of perceptions and hallucinations have common mental features. These common features, which are likely to be representational features of the state, explain why perceptions and hallucinations can share the same phenomenology. The possibility of a moderate view severely weakens the motivation for disjunctivism. The supporter of disjunctivism thought she could make a case for the claim that her position must be thought of as the default view. This is a train of thought first broached by Hinton but subsequently developed in great detail by M. G. F. Martin (whose 'The Reality of Appearances' and 'The Limits of Self-Awareness' are reprinted in DCR). Hinton's insight was that his opponent simply assumed that if a subject cannot discriminate between some of her experiences these must be the same, the disjunctivist points out that this conclusion does not follow. Thus, the burden of proof would be clearly on the shoulder of the Cartesian opponent. Furthermore, the opponent appears to have extra difficulties since he is trying to define the identity of experiences (a transitive notion) in terms of their indiscriminability (a notion which is notoriously intransitive). The emergence of a moderate position shifts the burden of proof on the shoulders of the disjunctivist who now needs to show why one must claim that these experiences have nothing 4 Alessandra Tanesini in common. The moderate position that they do not belong to the same type, but have common features now appears as the default position. Be that as it may, disjunctivism about experience faces numerous challenges. Perhaps, one of the best known arguments against the view is the socalled causal argument elaborated by Howard Robinson in his book Perception (a selection is reprinted in DCR). The argument is based on two premises: 1. It must be possible that in some instances the brain of a perceiver when genuinely perceiving is in the kind of neural state her brain is in when she hallucinates and 2. If two experiences have the same neural proximate cause then they must be given the same account. Hence, disjunctivism about experience must be false. The disjunctivist would typically reject the principle underlying the second claim, and in doing so they will not be alone since many externalists would also do the same. There is, however, a different variant of the causal argument, which raises more problems for disjunctivism. This version has been developed by Mark Johnson in his 'The Obscure Object of Hallucination" also collected in DCR. Johnston formulates the argument in terms of the possibility of a subjectively seamless transition from hallucination to veridical perception, and claims that disjunctivists cannot account for it. But what is of interest here is a different argument which is also deployed by Johnson. We have seen that the disjunctivist can simply reject the original version of the causal argument by saying that veridical perceptions have object-dependent contents. Since the external object is absent in the case of hallucinations, they must have different contents and so must belong to different kinds. However, consider now the case of an hallucination; its content does not depend on the existence of an external object. Thus, we must consider the possibility that the content of the hallucination is common with the veridical perception (which, however, would also have some extra object-dependent content). The advantage of positing the existence of a common core is that it facilitates an explanation of the possibility of seamless transitions from hallucinations to perceptions. Thus, Johnston's view can be seen as an example of the moderate position which, with disjunctivism rejects the view of experience as inner together with the claim that in experience we are not in direct contact with reality, but unlike disjunctivism postulates the existence of some common mental features between the good and bad cases. A similar moderate position about experience is also defended by Alan Millar in a paper reprinted in DCR. So far I have fleshed out disjunctivism about experience as a view about the representational content of experience, since I have taken mental states to be typed on the basis of their content. However, many – if not most – supporters of the approach do not follow this path. One who does is Sonia Sedivy who, in her contribution to PAK, defends the view that perceptual content is both object and property involving. Most disjunctivists, however, subscribe to relational accounts of perception and thus resist attributing any representational 5 The Non-Conjunctive Nature of Disjunctivism content to veridical perceptual experiences. Supporters of the relational theory do not always make a commitment to this kind of disjunctivism explicit, even though they must be so committed. It is for this reason, I presume, that the work of Charles Travis or John Campbell is not collected in either of these two volumes. The supporters of the relational theory of perception also owe us an account of the phenomenal character of perception. They need to account for the what it is like of experience. This position, which following Haddock and Macpherson, is best dubbed 'phenomenal disjunctivism' has in Martin its best known defender. It is perhaps the view with which the largest number of contributions in these two books are engaged. As Haddock and Macpherson observe disjunctivism about experience does not entail phenomenal disjunctivism, and my discussion above should make it clear that this is the case. On the other hand, as is also observed by Haddock and Macpherson, phenomenal disjunctivism entails disjunctivism about experience. Martin presents his brand of disjunctivism as a defence of Naïve Realism and as an opponent of both sense-datum theories and intentionalism with regard to their answers to the phenomenological argument from illusion. Martin intends to defend the naïve realist view that experience is phenomenally transparent because the objects themselves and their properties constitute the phenomenology of veridical experiences. Quite obviously, a different account needs to be provided for both illusions and hallucinations. There are several different ways the supporter of naïve realism can defend her position against the argument from illusions. Martin's account is framed in negative terms. In his view it is a mistake to assume that if two mental states cannot be told apart by reflective introspection alike, they must have the same phenomenal character. If we do not make this assumption, all we can say about veridical perceptions and matching hallucinations is that they share the epistemic feature of being indistinguishable from the veridical case. The sense of indiscriminability deployed by Martin is impersonal, rather than relative to the different discriminatory abilities of subjects. The disjunctivist, in Martin's view, should resist any demand to present a positive account of hallucination (such a demand is made by Jonathan Dancy, for example, in a paper reprinted in DCR). The disjunctivist can refuse to present a positive view of the phenomenal character of hallucinations, Martin holds, because his position is the default view since it is his opponent who is making an unargued assumption. However, the existence of moderate views which extend to accounts of phenomenal character undercuts this claim. It also weakens Martin's claim on behalf of disjunctivism to be the only view that accounts fully for the transparency of experience (understood here so strongly as to require that objects and their manifest properties are among its constituents). In 'The Reality of Appearances' Martin is agnostic as to whether there are common features between perceptions and hallucinations which might 6 Alessandra Tanesini explain why they cannot be told apart despite the fact that they do not have phenomenal characters of the same kind. Hence, in this paper Martin takes what I have called 'the moderate view' to be a form of disjunctivism. What mattered to him in that paper is that perceptions and hallucinations do not belong to the same 'fundamental kind' which is the only one which actually explains the character of perceptions. Under pressure from the modified version of the causal argument discussed above, Martin's position has changed with regard to matching hallucinations. In 'The Limits of Self-Awareness' he argues that if in these instances one could explain the character of hallucinations by reference to their shared features with veridical perception, these features –rather than its relation to reality – would also explain the character of the corresponding matching perceptions. Hence, he holds that no positive account for hallucinations of this sort is possible. Yet this enforced silence has not found much support among other disjunctivists. It has also been subject to intense criticism, the papers by Susanna Siegel and by A.D. Smith (both in PAK) offer sustained criticisms of Martin's epistemological account of illusions and hallucinations. The negativity of Martin's position is also rejected by some fellow disjunctivists, in particular William Fish who in 'Disjunctivism, Indistinguishability, and the Nature of Hallucination' (in PAK) offers a positive account of hallucinations which grounds their indiscriminability from veridical perception in the similarity of their effects (a similar view is also presented by Scott Sturgeon in his essay also in PAK). As it should be clear from the discussion above, in my view the jury is still out about the viability of disjunctivism in the philosophy of perception. At least in the case of phenomenal disjunctivism it might be the case that non-conjunctive moderate views have the upper hand. B. PERCEPTUAL KNOWLEDGE The most prominent exponent of disjunctivism in epistemology is John McDowell and selections from his paper 'Criteria Defeasibility, and Knowledge' are included in DCR. This paper contains one of McDowell's earliest formulation of his views which have been extremely influential. McDowell asks us to compare cases where I can tell how things are in my immediate environment by looking with deceptive cases where one is mislead by appearances. It is tempting to say that because from a subjective point of view it is impossible to discriminate between the two cases, the evidence provided by experience must be the same in both cases. That is to say, it is tempting to believe that in both kind of cases our experience provides us with at most defeasible evidence for our perceptual knowledge. In this paper, and elsewhere, McDowell urges us to resist this temptation, and reject what he calls 'the highest common factor' view according to which the evidence for our per7 The Non-Conjunctive Nature of Disjunctivism ceptual knowledge must be something wh ich is available in both the deceptive and the non-deceptive cases. Instead, McDowell claims that in the nondeceptive cases, our evidence does not fall short of the facts. The facts themselves are our experiential intake on which our non-inferential knowledge is based. In the deceptive cases, on the other hand, our experiential intake is a mere appearance. Hence, McDowell's view is a form of disjunctivism about the evidence for perceptual knowledge and belief: whilst knowledge is based on facts, in the deceptive cases belief is based on mere appearances. It would be easy to conclude that McDowell's position amounts to a form of externalism. One might think that in his view the reason why the epistemic standing of the subject differs in the deceptive and non-deceptive cases is due to factors external to the subject. This conclusion must also be resisted. Instead, in McDowell's view the facts themselves are not bluntly external to subjectivity and that is why McDowell's view is in reality a form of internalism. This aspect of McDowell's position is brought out in sharp relief in Duncan Pritchard's contribution in PAK. The paper entitled 'McDowell's Neo-Mooreanism' offers an interpretation of McDowell's disjunctivism as a form of Neo-Moorean response to scepticism about the external world. Pritchard's careful analysis of McDowell position shows how McDowell can consistently hold that epistemic support for one's claims is provided by one's reasons, and accept the internalist constraint that one's reasons must be reflectively accessible to the subject, without denying that in the non-deceptive case one's reasons are factive and thus fundamentally different from the reasons one has in the deceptive cases. These views can be held consistently because, as Pritchard als o shows, the reflective accessibility of one's factual reason does not entail that one should be able to know by reflection alone the (seemingly empirical) fact that one is in the good non-deceptive case, rather than the bad deceptive one. It is now widely accepted that McDowell's position does not entail disjunctivism about experience, and that McDowell himself probably does not subscribe to this view. Considerations for these claims are convincingly highlighted by Byrne and Logue both in 'Either/Or' and in the introduction to DCR. But it is the introduction by Haddock and Macpherson to PAK that offers the best and most patient discussion of the complex relations of McDowell's epistemological disjunctivism to its experiential cousin. Unfortunately, this matter was quite unclear for sometime. The confusion was in part due to McDowell's mention of the argument from illusion in his initial presentation of disjunctivism about perceptual knowledge. It should be noted, however, that the converse entailment holds. Hence, disjunctivists about experience must also subscribe to disjunctivism about perceptual knowledge. The section about epistemology in PAK also includes two contributions one by McDowell and one by Crispin Wright about the relation between disjunctivism and scepticism about the external world. In his paper Wright ar8 Alessandra Tanesini gues that disjunctivism is dialectically ineffectual in silencing the sceptic; McDowell, instead, defends the view that this position might not refute the sceptic, but nevertheless it undermines its attractiveness. Be that as it may, the value of disjunctivism in epistemology does not lie exclusively in its ability to answer scepticism as many of the papers in the epistemology section of PAK successfully demonstrate. C. ACTION Disjunctivist accounts in the philosophy of action are a recent development but these views are well represented in PAK. Although there are different forms that disjunctivism can take in this area perhaps the most interesting concerns acting for reasons. A defence of such a disjunctivist account is offered in Jennifer Hornsby's contribution in PAK. The position is an analogue of McDowell's disjunctivism about perceptual knowledge. In the same manner in which McDowell urges us to deny that veridical and non-veridical experiences offer the same sort of evidence for our perceptual judgments, Hornsby urges us to resist the temptation to think that the only reasons for acting are beliefs, which of course could be either true or false. Instead, she argues that our reasons for acting can be factive, they can be given by what we know. In her view one of the advantages of this position is that it preserves the connection between normative reasons (considerations in favour of the action) and motivating reasons (considerations that explain why we acted as we did). This section of PAK also include an essay by Jonathan Dancy which sets out why and where he disagrees with Hornsby. In particular he denies that we must attribute a specific role to knowledge, as opposed to degrees of confidence in belief, in the theory of acting for reasons. He also suggests, for related reasons, that normative and motivating reasons must be thought as roughly equivalent. Whether or not Dancy is right on these points, there is no doubt that disjunctivism offers the promise of a novel approach to the philosophy of action. In general, these volumes are the best place in which to look to appreciate the significance of disjunctivism in re-shaping old debates. Philosophy School of English, Communication and Philosophy Cardiff University Humanities Building, Colum Drive Cardiff CF10 3EU, UK E-Mail: Tanesini@cardiff.ac.uk