What the Disjunctivist Knows

Mon, 2 Jun 2008 14:03:49 +0100

Does disjunctivism about perceptual experience provide a satisfactory response to the sceptic?
I. Introduction
Disjunctive accounts of perceptual experience have been advanced by Hinton (1973), Snowdon (1990) and others (e.g. Martin 2004) as an alternative to traditional accounts of perception that conceive of such experience on the model of an externally caused ‘inner object’ or event. Whilst generally regarded as a thesis concerning the nature and individuation of experience, some philosophers — chiefly John McDowell (1982; 2008) — have emphasised the theory’s epistemological benefits, claiming that it is capable of explaining how we can have knowledge of the external world as opposed to knowledge of mere appearances — an issue that dates back to the work of Descartes (1641), Hume (1739; 1748), Locke (1690), and others. This essay evaluates whether the disjunctivist conception of perceptual experience is able to yield a satisfactory response to such external world scepticism and, if so, what kind of a response it is. In particular, I will focus upon McDowell’s claim that disjunctivism removes a crucial ‘prop’ upon which such scepticism depends, thus placing the disjunctivist on a firmer dialectical footing than his opponent — a claim that is vigourously denied by Wright (1982; 2008). I begin by describing the disjunctivist conception of perceptual experience in Section II, followed by McDowell’s ‘epistemological disjunctivism’ in Section III. Section IV deals with the issue of higher-order scepticism, and I conclude the final section with some remarks concerning the effectiveness of the disjunctivist response.
II. Perceptual Disjunctivism
The central claim of disjunctivism is that the veridical perception of an external object X and a phenomenally indistinguishable hallucination of X do not, as a matter of conceptual necessity, share a common psychological or experiential element. Rather, in the genuinely perceptual or ‘good’ case, the experience is essentially relational, since it relates the subject to an external object; e.g. a zebra (to borrow Dretske’s [2005] example). In the non-perceptual or ‘bad’ case, the experience is non-relational since it only involves there seeming to be a zebra in front of me, and thus has no external object. By application of Leibniz’s Law, a relational and non-relational experience cannot be numerically identical, since they have different properties, thus giving rise to the so-called disjunctive conception of experience. My experience of it looking to me as if there is a zebra in front of me is either a case of my seeing that there is a zebra or of my imagining, hallucinating, etc. that there is a zebra, where the two disjuncts are externally, rather than internally, individuated. Whilst the disjunctivist is not committed to maintaining that the two cases have literally nothing in common, such as the subject’s brain state or how the experience represents the world as being, the claim is that they constitute two different types of experience — or at least that this cannot be ruled out a priori (Snowdon 1990: 129). This may be contrasted with the traditional ‘Lockean’ conception of experience as an inner process or state that is common to both veridical and non-veridical cases, and which in a materialist theory of mind might be identified with or supervene upon a subject’s brain state, for example.1
Perhaps the greatest advantage of such ‘perceptual disjunctivism’ is its ability to explain how perception can make external objects available for demonstrative thought (Snowdon 1990: 143). On the Lockean conception of experience, it is unclear what makes it possible for me to think of that particular zebra, even when it is right in front of me, since the psychological experience that I enjoy is non-relational, and therefore logically and metaphysically independent of the object itself. In order to bridge this gap, some further (e.g. causal) condition must be satisfied since the very same experience would be compatible with there being no such external object. The disjunctive conception of perceptual experience, on the other hand, conceives of the subject as standing in some particular relation (e.g. that of seeing) to an actual object, from which the appearance cannot, so to speak, become ‘detached’, thus making the object available for demonstrative thought. The relationality of perceptual experience makes it essentially object- or world-involving, as opposed to hallucination, which is a purely internal phenomenon.2
Before moving on to consider the epistemological significance of disjunctivism, it is worth noting its connection with some broader philosophical themes. The disjunctivist thesis essentially amounts to a claim about the scope of experience. The traditional conception of experience is that it has narrow scope, with experiences being individuated phenomenologically by virtue of their representational content or phenomenal character. The disjunctive conception, on the other hand, claims that experience has broad scope with experiences being individuated epistemologically on the basis of factors external to the subject. Just as externalism about meaning (e.g. Putnam 1975; Burge 1979) or representational content (Tye 1993) is intended to overcome problems concerning the individuation of thoughts or sensations by taking external contextual factors into account, perceptual disjunctivism is intended to explain how the nature of experience can differ even where the content of those experiences is phenomenologically indistinguishable. Corresponding to these notions of broad and narrow experience are two different notions of justification. Let us say that an individual is subjectively justified, or S-justified, if and only if they have good reason to believe X and are ‘epistemically blameless’ in the sense that they have done nothing wrong in their method of acquiring the relevant belief. Alternatively, a subject is all-things-considered justified, or A-justified, if and only if, were they in possession of all the facts, they would be justified in believing X.3 External world scepticism can be described as attempting to drive a wedge between S- and A-justification, claiming that we are only ever entitled to claim the former, whilst only the latter is capable of yielding knowledge. McDowell’s response to this challenge is both subtle and radical since it attempts to undermine the plausibility of the sceptic’s position by reversing the direction of explanation for what is required for knowledge, as described below.
III. Epistemological Disjunctivism
McDowell’s response to external world scepticism has two distinct phases, or parts, each of which I shall consider in turn. Firstly, the disjunctive conception of experience is used to explain how we can have direct, non-inferential knowledge of the external world. This is intended to secure the possibility of first-order knowledge in the face of sceptical doubt. Secondly, a form of transcendental argument is employed to undermine the plausibility of the sceptic’s own account of knowledge. This is intended to shift the burden of proof away from the common-sense notion of knowledge that we ordinarily employ, and which McDowell’s account supports, and onto the sceptic, who must then give good reason why we should call our everyday knowledge claims into doubt. The issue of second-order knowledge, i.e. our knowing that we know, is not directly addressed by McDowell, but I will argue that a similar strategy may be employed as for first-order knowledge using the disjunctive conception of experience to justify our second- and higher-order knowledge claims.4 It is important to note that at no point does McDowell profess to have refuted the sceptic, but rather his intention is ‘diagnostic’ (McDowell 1992: 378). Indeed, he agrees with Stroud that ‘the worst thing one can do with the traditional question about our knowledge of the world is to try to answer it’ (Stroud 1980: 56, in McDowell 2008: 384). His strategy does not therefore aim to convince the sceptic of the falsity of his argument on some mutually acceptable grounds, but rather to gain dialectical advantage by undermining the coherence and apparent attractiveness of the sceptical position. This will become relevant when evaluating the success (or otherwise) of McDowell’s epistemological disjunctivism.
McDowell (2008: 378–9) maintains that the initial plausibility of external world scepticism (hereafter simply referred to as ‘scepticism’) stems from the fact that the traditional Cartesian view of perceptual knowledge does not adequately secure the possibility of epistemic access to worldly facts. On the narrow conception of experience described above, perceptual experience warrants belief — and thereby knowledge — only when it stands in the appropriate (typically causal) relation to the relevant state of affairs in the external world. However, since precisely the same experience could be enjoyed in the absence of this state of affairs — in the case of a hallucination, for example — such experience can at best give defeasible warrant for belief, since it cannot yield knowledge unless the relevant external condition is satisfied; e.g. when there really is a zebra in front of me. For McDowell, this places perceptual knowledge on dubious foundations since the ‘gap’ between what experience warrants and knowledge makes it easy for the sceptic to claim that the necessary conditions may not have been satisfied due to some as-yet-unconsidered factor, such as our being deceived by a malicious demon (Descartes 1641: 15), by being a ‘brain in a vat’ (Putnam 1981), or through the presence of some cleverly disguised mules (Dretske 2005). This amounts to the claim that, since perceptual experience only involves its seeming to us that p, such experience can only warrant disjunctive beliefs of the form: either we are perceiving that p or we are imagining (hallucinating, etc.) that p. This places the sceptical scenario on precisely the same footing as that of veridical perception. Expressed in the terms defined above, when conceived as having narrow scope, perceptual experience can only yield S-justification, and never A-justification, since no possible evidence is sufficient to rule out the possibility that we are being systematically deceived.
By rejecting the Lockean view in favour of a disjunctivist account of perceptual experience as individuated in terms of its epistemological — rather than phenomenological — properties, McDowell aims to prevent the first-order sceptical argument from gaining a foothold. On this view, veridical perceptual experience is relational by definition and so involves a subject standing in a particular relation to some external world object.5 The presence of the object is intrinsic to the nature of the experience, since on the disjunctivist view without it the subject could no longer be said to have had the same experience. In the ‘good’ case, perceptual experience warrants the belief that there is, for example, a zebra in front of me, since the experience itself entails that the object is present. In the corresponding ‘bad’ case — e.g. in the presence of a cleverly disguised mule — it merely seems that such an object is present, and so any resulting belief that there is a zebra would be unwarranted. In contrast to the Lockean picture where non-disjunctive experience only warrants disjunctive (i.e. sceptical) belief, we now have two disjuncts, one of which warrants belief (or knowledge) and the other which does not, but both of which are phenomenologically indistinguishable to the subject. On McDowell’s picture, however, the fact that the subject may not know which disjunct their experience falls under does not undermine their epistemic standing in the ‘good’ case. At worst, they may form an erroneous (i.e. unwarranted) belief by mistaking a hallucination or fake for the real thing, but this is different to saying that their warrant is defeasible. Indeed, it is arguably the notion of defeasibility, which arises from the narrow conception of perceptual experience, that enables the sceptic to claim that we only ever have S-justification, since we cannot know whether the relevant external conditions have been satisfied. For McDowell, on the other hand, we can have both S- and A-justification in virtue of our direct epistemic access to the facts through our faculties of perception and higher-order cognitive abilities.
It is crucial to McDowell’s account that the reason or justification which warrants perceptual knowledge is not something over and above or presupposed by experience, but perceptual experience itself. Thus, instead of perceptual justification (e.g. seeing a zebra-looking object) being distinct from the beliefs that it warrants (i.e. that there is a zebra), my seeing that there is a zebra directly warrants my belief, since the experience already ‘takes in’ the relevant fact (McDowell 1982: 472). This closely matches ordinary linguistic practice, since when prompted to justify a given piece of perceptual knowledge we typically respond by saying that we just see that it is so, rather than offering any independent justification in support of this fact or the reliability of our perceptual faculties.6 Wright (1982: 345), however, rejects this proposal, claiming that it presupposes precisely what the sceptic denies, i.e. that there is an external world, making it unsuitable for use in an argument that purports to grant knowledge of the external world since it is effectively question-begging. McDowell (2008: 384–5) responds by noting that ‘the point of the disjunctive conception is not to improve our resources for such arguments’, but rather to ‘remove a prop’ (Wright’s own phrase) upon which such scepticism depends; i.e. the assumption that perceptual experience cannot by itself ‘reveal how things are’ (ibid.), but instead stands in need of independent justification. By rejecting this assumption, the disjunctivist effectively blocks the possibility of first-order doubt as to whether such justification is available, since it is no longer separable from the experience itself, instead forcing the sceptic to concentrate upon the second-order issue of whether the experience is in fact perceptual or not, as discussed below. Consequently, Wright’s (2008: 398) insistence that a disjunctive conception of experience fails to warrant knowledge or belief is beside the point, since it is not the disjunction as a whole to which warrant is attached, but to each of the disjuncts (McDowell 2008: 386). This insistence demonstrates the pull of the precisely the narrow conception of experience that the disjunctivist denies, effectively conflating the issue of whether a subject has warrant with the separate question of whether the warranting status of an experience is accessible to the subject, where the latter is a matter of second-order knowledge.
The model of knowledge that McDowell presents is one in which the subject is genuinely ‘open to the world’ and the facts within it without requiring the satisfaction of further (e.g. causal) conditions. Due to its relational nature, the broad conception of perceptual experience is essentially world-involving, and so there is nothing to come between the subject and their knowledge of the world in the ‘good’ case from which the sceptic can construct his counter-argument. Although this may show how perceptual knowledge of the world is possible, it falls short of banishing sceptical doubt altogether since there is as yet no way for the subject to tell whether her experience is in fact perceptual or not, since (by stipulation) the ‘good’ case is subjectively indistinguishable from the ‘bad’.7 At this point in the dialectic, the sceptic would seem to have two options. He can either accept McDowell’s account of perceptual experience and redeploy his argument against the possibility of second-order knowledge, or else reject the disjunctivist conception of experience upon which it is based. However, since it cannot be assumed a priori that disjunctivism is false (Snowdon 1990: 129), it is not clear that the latter option is available, and so the sceptic must directly confront the legitimacy of second-order knowledge claims.8
IV. Second-Order Scepticism
Having secured the possibility that we have perceptual knowledge of the external world, we now turn to the second part of McDowell’s argument, which concerns the issue of whether we can know (or claim) that we have such knowledge. Rather than attempting to argue for this from a neutral starting point that is acceptable to the sceptic — a task that he acknowledges to be futile (McDowell 2008: 386) — McDowell instead employs a transcendental argument aimed at undermining the apparent coherence and plausibility of the sceptic’s own position (ibid. 382). The argument proceeds from the premise that, given the importance and centrality of the concept of knowledge in our everyday experience as a bearer of objective significance, we are rationally bound to adopt a model of knowledge that can make sense of this fact. After all, if our concept of knowledge were completely without foundation then we would be unable to make sense of many of our everyday practices, including perception, learning, scientific investigation, and so on. McDowell claims that the sceptic both grants that our knowledge aims to have ‘objective purport’ whilst simultaneously denying that it can do so in practice (ibid. 380). This position is unstable since it undermines the very idea of knowledge that the sceptic is presupposing, as well as failing to make any of the above practices intelligible. The disjunctivist, on the other hand, can plausibly claim that in the ‘good’ case, experience does indeed have objective purport, and so the distinction between knowing and not knowing is well-founded, thereby rendering our practices intelligible. All other things being equal, we should prefer a model of knowledge that is able to do this, thus making the disjunctivist’s account of knowledge more plausible than the sceptic’s.
This argument is all well and good, but even if the sceptic were to grant McDowell his conclusion, it is still possible (although perhaps unlikely) that all of our experience falls under the ‘bad’ case. After all, this is precisely what the machinations of the Cartesian demon or vat-scientist were supposed to illustrate: that it is entirely consistent with the content of our experience (narrowly construed) that all of our beliefs could turn out to be false for a reason that it is beyond our powers of discrimination to discount. Whilst McDowell appears reluctant to engage with this possibility, a suitable McDowellian response may perhaps be given along the following lines. Just as our first-order perceptual abilities place us in a direct relation to worldly objects and facts, we also have second-order cognitive abilities that enable us to tell from the surrounding context and situation whether these first-order experiences are in fact veridical.9 Indeed, most if not all perceptual experiences contains some indication of their own veridicality, which is why we are inclined to take some experiences at face value and to doubt others; e.g. a fleeting glimpse, unconvincing facsimile, or dream-like visual impressions. This is not to say that such second-order abilities are infallible any more than our perceptual abilities are infallible since we do not know in all cases whether we are being deceived. However, the McDowellian conception of knowledge is perfectly able to explain how it is that we have direct epistemic access to the fact that we can and do perceive veridically in a wide variety of cases. Just as having a particular (broadly constituted) perceptual experience can itself warrant first-order belief or knowledge, the very same experience, along with the appropriate contextual and cognitive factors, can warrant the corresponding second-order knowledge claim. As with first-order knowledge, such claims do not require the existence of any independent justification or warrant over and above the initial perceptual experience along with our previous training and experience in recognising instances of ‘good’ and ‘bad’ cases. Thus, the claim is not that we always — or even most of the time — know whether or not we perceive veridically, but that in the ‘good’ case, we can know that we know since our higher-order cognitive abilities are able to ‘take in’ this higher-order fact. Of course, there is still the possibility that in the ‘bad’ case we may be mistaken, but the possibility of such false knowledge claims does not justify the sceptical conclusion that none of our knowledge claims are warranted, since the disjunctivist’s conception of experience has already shown how we can have direct epistemic access to the facts in the ‘good’ case.
The structure of the above argument exactly parallels that of McDowell’s argument for first-order knowledge. Once again, the sceptic cannot rule out the possibility that the acquisition of such higher-order knowledge is possible, but will seek to cast doubt upon its reliability, shifting the argument to an even high-order form of scepticism. Surely, he will claim, any malicious demon or evil scientist worth their salt would set things up so that it would seem to us as if we had knowledge even where we have none? Here it may seem as if the disjunctivist response does little more than to set up an infinite regress in which both sides perpetually claim victory by invoking ever higher-order cognitive abilities and higher-order sceptical doubts. However, at this stage the McDowellian disjunctivist can justifiably claim that their model of knowledge offers a more plausible basis for our everyday use of the term than that of the sceptic, which seeks to render the very possibility of knowledge unobtainable, thereby rendering the concept meaningless.10 The disjunctivist account of first-order perceptual and higher-order cognitive abilities is therefore better placed to make sense of our everyday talk and practices surrounding knowledge whilst acknowledging that we may be more or less fallible in individual cases. What it denies is that such fallibility requires us to engage with the sceptical argument on its own terms, since both first- and higher-order knowledge are, so to speak, already within our grasp.
V. Conclusion
Whether disjunctivism is capable of supporting a satisfactory response to external world scepticism largely depends upon the issue of who such a response is required to satisfy. McDowell’s epistemological disjunctivism will certainly be unsatisfactory to any committed sceptic, who will accuse him of rejecting the Lockean conception of experience out of hand, or to those who will settle for nothing less than a full-blown refutation of the sceptic’s argument. On these views, perhaps the best that could be said about McDowell’s account is that it re-describes the facts to show how knowledge might be possible, but falls short of giving any decisive response to the sceptic, and ultimately fails to engage with the argument. Such a conclusion would, however, be unwarranted since it both underestimates the resources available to the disjunctivist about perceptual experience as well as misreading the whole tenor of McDowell’s approach which was to avoid the need to engage with scepticism on its own terms — a task that arguably never had any prospect of success in the first place.
Perhaps a better way of understanding McDowell’s anti-scepticism is as a form of Wittgensteinian ‘philosophical therapy’ (McGinn 1997: 23), designed not to refute the sceptic, but to relieve us of an anxiety concerning the demands that knowledge places upon perceptual experience. As such, we need only be satisfied that first- and higher-order knowledge is available to us in the ‘good’ case, and that the sceptic’s argument, whilst acknowledging its initial appeal, need not prove compelling provided that we are willing to accept that justification for both types of knowledge can arise from having a particular kind of externally individuated perceptual experience. By conceiving of knowledge in terms of direct epistemic access to the world, or facts, rather than attempting to build it up from subjective justification plus the satisfaction of some further external condition, McDowell rejects the sceptical premise that we require independent justification over and above perceptual experience — our primary means of knowing about the world. This in turn underpins an attack on the sceptic’s model of knowledge, which fails to account for our everyday ‘forms of life’, thereby shifting the burden of proof back onto the sceptic. In this way, McDowell seeks to reassure us that we should not be seduced into letting the logic of the sceptic’s position undermine our confidence in our everyday practices and knowledge claims. When expressed in these terms, disjunctivism supports a powerful and effective remedy against what tempted us towards scepticism in the first place, thus putting our sceptical doubts back into perspective, rather than placing them at the forefront of our epistemological concerns.
——————
1 Disjunctivism does not entail that experiential states do not supervene upon brain states, only that they do not merely do so.
2 Martin (2004: 42–3) argues that disjunctivism also has the benefit of presenting the least revisionary account of perceptual experience, since both sense-datum theory and traditional empiricism require that we are mistaken as to the nature of the objects of experience.
3 Neither kind of justification entails the other, since it is possible for a subject who is A-justified to have good evidence for the falsity of their belief, thus undermining S-justification, and vice versa.
4 For brevity, I will treat knowledge claims as a form of second-order knowledge. Nothing in the argument turns on this distinction.
5 Here, I will talk only of objects, but the argument applies equally to facts.
6 Compare, for example, the absurdity of responding with the disjunctive justification of ‘either I see that it is so or I am hallucinating it, and I have good reason to believe that my perception is reliable’.
7 Indeed, Wright (2008: 401) argues that Cartesian scepticism was always an issue of second-order not first-order knowledge, and that McDowell’s argument simply misses the point.
8 Whether it would be sufficient for the sceptic to remain agnostic about which model of perception is correct is discussed below.
9 Millar (2007, 2008, forthcoming) calls such capacities ‘recognitional abilities’.
10 An alternative strategy would be to ‘relativise’ the concept of knowledge to whatever epistemic situation it turns out we are in, as per Putnam (1981), but this would concede too much to the sceptic.

Bibliography
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Haddock, Adrian and Fiona Macpherson (eds.) 2008: Disjunctivism: Perception, Action, Knowledge. Oxford: Oxford University Press.
————— 2008: ‘The Disjunctive Conception of Experience as Material for a Transcendental Argument’. In Haddock & Macpherson (eds.), pp. 376–89.
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————— 1748: An Enqury Concerning Human Understanding. Reprinted in T. L. Beauchamp (ed.), Oxford: Oxford University Press, 1999.
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————— 2008: ‘Perceptual-Recognitional Abilities and Perceptual Knowledge’. In Haddock & Macpherson (eds.), pp. 330–47.
————— forthcoming: ‘Disjunctivism and Scepticism’. In The Oxford Handbook to Scepticism, J. Greco (ed.), Oxford: Oxford University Press.
McDowell, John 1982: ‘Criteria, Defeasibility, and Knowledge’. Proceedings of the British Academy, 68, pp. 455–79.
————— 2008: ‘The Disjunctive Conception of Experience as Material for a Transcendental Argument’. In Haddock & Macpherson (eds.), pp. 376–89.
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Neutral Monism as a Response to the Conceivability Argument

Sat, 31 May 2008 19:04:37 +0100

I. Introduction
The conceivability argument (hereafter abbreviated as CA) is an argument against any kind of materialism that takes mental and physical events1 to be numerically identical, but only contingently so. Such arguments have been given by Descartes (1641: §4), Kripke (1980) and Chalmers (1996) and concern the conceivability, and thereby the possibility, of disembodied minds and mindless bodies, the latter of which are often referred to as philosophical ‘zombies’ (ibid. 94) — beings that look and behave exactly like us and yet have no ‘inner life’ or conscious experience. Standard responses to these arguments include a priori materialism (Stoljar 2000), substance or property dualism (Chalmers 1996), and contingent identities between ‘non-rigid designators’ (Jacquette 1987), as described in Section II. Perhaps a less well-known response, however, is based upon the metaphysical doctrine of neutral monism — the view that the universe is neither fundamentally physical nor mental, but composed of ‘neutral’ elements from which all other substances and properties are comprised. This view was famously held by Russell (1921; 1927), Mach (1886) and James (1904), amongst others, although here I shall concentrate less upon the details of neutral monism itself and more upon the structure and plausibility of the response to CA that it facilitates. In particular, I will draw upon recent work by Maxwell (1978) and Stoljar (2001a; 2001b) who, despite describing their accounts as physicalist, could be equally described as holding a form of neutral monism, since the structure (although not their interpretations) of these accounts matches that given by neutral monism.
I begin by describing Kripke’s version of CA in Section II, along with some possible responses to it. In Section III, I present a neutral monist interpretation of Maxwell and Stoljar before highlighting some potential problems for this approach in Section IV. Finally, I conclude that the neutral monist response to CA is successful, but may still be problematic due to the way that it accounts for the metaphysics of perceptual experience.
II. The Conceivability Argument
The type of materialism that CA is opposed to claims that in some, but not all, possible worlds, each mental event can be identified with some corresponding physical event such that they are one and the same thing. This ‘type-B’ materialism (Chalmers 1996: 165) does not mandate that this is the case in all possible worlds — i.e. the entities in question are not necessarily identical — but merely that such identities hold in the actual world, along with a suitable selection of close possible worlds. Moreover, CA applies to both type-type and token-token identity theories, the first of which posits identities between mental and physical event types, e.g. ‘pain = C-fibre firings’, and the latter between particular mental and physical events, or tokens, e.g. ‘my headache at 2pm = these activations of nerve endings within my brain at that time’. For the purposes of this essay I will concentrate mainly upon the latter, but similar considerations apply to both. It is important to note that the relationship that materialism posits is one of identity, and not mere correlation. Consequently, certain pains just are C-fibre firings (to borrow Kripke’s example) and so must possess precisely the same properties — something that is a potential problem for any identity theorist (see Section IV: the grain objection).
Kripke’s version of CA proceeds from what he takes to be a basic intuition about the connection between mental and physical phenomena. Kripke claims that we can imagine a particular pain (e.g. my headache at 2pm) existing without the particular pattern of nerve activations that the materialist claims it is identical with. Had the relevant portions of my brain been replaced with identically functioning pieces of silicon, for example, then it seems that I could have had the same pain in the absence of these particular nerve activations. More generally, we can conceive of minds that exist independently of any body, in which case their ‘pains’ and other mental phenomena would be independent of all physical activity. Of course, the existence and status of such intuitions is highly contentious, and many philosophers (e.g. Stich 2004) question their significance. Even if such do intuitions exist, they may be inaccurate or misleading due to our lacking knowledge of the relevant mental and physical domains (e.g. the laws of physics). Alternatively, they may be the result of exposure — direct or otherwise — to the works of such philosophical luminaries as Descartes and Kripke, or traditional religious beliefs, rather than indicating an innate proclivity to countenance the possibility of immaterial spirits or ‘zombies’. For the sake of argument, however, I will accept that such intuitions are widespread and that we can and do have knowledge of modal facts on the basis of them since, in the absence of this link between conceivability and possibility, it is difficult to see what else could underpin genuine modal knowledge.2
Kripke’s argument also draws upon the modal semantics that he himself created (Kripke 1963). He defines a rigid designator as any linguistic term that identifies the same individual in every ‘possible world’ in which they exist. This category includes most proper names as well as some demonstratives, such as ‘that pain’. Conversely, a non-rigid designator picks out different individuals in different possible worlds, as is generally (although not always) the case with definite descriptions, such as ‘the author of Naming and Necessity’. This picks out different objects in other possible worlds, since it is not an essential property of Saul Kripke that he wrote this particular work.3 Due to the indiscernibility of identicals (i.e. Leibniz’s Law) and the way in which objects in possible worlds are ‘stipulated’ rather than ‘discovered’ (Kripke 1980: 44), all identity statements between rigid designators turn out to be a posteriori necessities. Whilst the detailed arguments for this thesis lie beyond the scope of this essay, the necessity of identity is central to both Kripke’s modal semantics and to CA, as well as being widely accepted by contemporary philosophers and logicians.
Putting all this together with the above intuition concerning the apparent contingency of mind–brain identity statements, and assuming that the relevant terms are in fact rigid designators, Kripke presents the materialist with the following dilemma. Either:
The equivalence between mental and physical events is only contingently true, i.e. true in just some possible worlds, in which case such correlations are not identity statements, since this would contravene the necessity of identity, and so type-B materialism is false, or
Such identities are necessarily true, i.e. true in all possible worlds, in which case the materialist must provide some explanation for their apparent contingency, as established by the above intuitions.
Kripke takes it that proponents of materialism must take the latter route if they are to vindicate their theory, although this is by no means the only option. One could, for example, accept the necessity of identity and question the validity of the relevant modal intuitions (although neither Kripke nor Chalmers finds this option plausible). Alternatively, one could reject the semantic framework that gives rise to the problem, claiming that necessary of identity is merely an artefact of the way in which Kripkean possible worlds are specified. In the absence of an alternative modal semantics, however, this option is unattractive as it calls much recent philosophy into doubt; e.g. Chalmers (2004) and Stalnaker’s (2001) two-dimensional semantics. A more promising strategy might be to deny that the relevant mental and/or physical terms are in fact rigid designators. On this view, ‘that pain’ or ‘those C-fibre firings’ might be definite descriptions that only contingently pick out the relevant events, rather than doing so necessarily. In this case, however, Kripke (1980: 331) argues that the relevant non-rigid terms may simply be replaced with suitable rigid designators, and the argument run again to show that these are not identical. A determined materialist might resist this move on the basis that it is question-begging, but this would seem to undermine the materialist’s own claim that pains, nerve activations etc. are natural kind terms, since we do normally think of terms such as ‘water’ and ‘H2O’ as picking out the same thing in all possible worlds. This response does, however, highlight a major assumption in Kripke’s argument, thus creating a point of departure for the kind of ‘non-materialist physicalism’ that is discussed in Section III.
In response to the above dilemma, Kripke considers the attempt to explain the apparent contingency of mind–brain identity statements by analogy with other comparable scientific identities, such as those between heat and molecular motion, or water and H2O. In these cases, Kripke argues that the apparent contingency arises from the presence of a suitable phenomenological counterpart, namely the sensation of heat or the observable properties of water, by which the left-hand term is normally picked out. He then argues that we are liable to mistake the contingency of the causal relationship between this counterpart and the right-hand term for the contingency of the original identity. For example, although it is conceivable that in some possible world the sensation of heat is caused by something other than molecular motion — such as green light, for example — this does not show that heat is not identical to molecular motion, but merely that the sensation by which we detect heat is contingently caused by it. The resulting ‘illusion of contingency’ leads us to falsely conclude that such identities are contingent, when in fact they are necessary, as Kripke’s modal semantics predicts. In the case of pain and other phenomenal states, however, no such phenomenal counterpart is available, since pain (what it’s like to see red, thinking, etc.) is already a phenomenal state. Consequently there is no possible world in which ‘pain’ is distinct from the sensation of pain, since pain simply is the sensation of pain, or else such a world would fail to explain the apparent contingency of ‘pain = C-fibres firing’, since there is no reason why we should identify the non-phenomenal counterpart with the sensation pain. In the absence of any other explanation for the apparent contingency of mind–brain statements, Kripke concludes that such identities must be false and that, by implication, materialism is false.
Some philosophers (e.g. Hill 1997) have responded to this argument by attempting to provide an alternative explanation for the apparent contingency of mind–brain identity statements. Others (e.g Jacquette 1987) have sought to redefine the relevant mental and physical terms in a way that makes the contingency (apparent or otherwise) explicable. Throughout the remainder of this essay, I shall concentrate on one such approach that arises from the theory of neutral monism (Stubenberg 2005), a metaphysical doctrine which posits that the fundamental constituents of the universe are neither physical nor mental, but rather ‘neutral’ elements from which both the mental and the physical are comprised, or whose properties they supervene upon. My account is largely based upon Maxwell (1978) and Stoljar (2001a), but whilst they class their theories as physicalist, I claim that they are characteristically neutral — although since the structure of both theories is substantially equivalent, the difference turns out to be largely terminological.
III. Neutral Monism
The neutral monist response to CA is based upon two key assumptions. The first is that physical science does not tell us everything there is to know about the nature of the universe (Stoljar 2001a: 313; Maxwell 1978: 395). This is not simply due to the incompleteness of current physical theories, but that they can only provide us with a certain type of information about the world, namely its ‘causal structure’ (ibid. 346). Nevertheless, physics does (according to Maxwell) posit the existence of some underlying substance or elements that instantiate the structural properties that we can investigate empirically, such as the observable properties of matter and energy.4 These purely formal properties may be contrasted with the intrinsic properties of the underlying ‘causal network’ (ibid.), which are distinct from, but nevertheless give rise to, all of the causal properties described by physics. It is a logical consequence of this view that it would be possible for a given causal (i.e. physical) structure to be instantiated by a number of different causal networks. This makes the causal properties of any given part of the network (e.g. a C-fibre firing) a contingent, rather than necessary, property of the underlying network, since it does not possess this property in all possible worlds. The second assumption is that both physical and mental events are comprised of, or supervene upon, a single kind of entity which I shall refer to as a neutral element. Whilst the structural properties of these elements give rise to everything we observe in the physical world, as described above, their intrinsic properties correspond to the nature of ‘inner’ mental phenomena, such as sensations, thoughts, consciousness, and so on.5 Neutral monism is thus able to account for the intimate connection between the mental and physical domains by explaining both types of phenomena as being comprised of a single common or ‘neutral’ element.
At this point, neutral monism parts company with Maxwell and Stoljar, who describe the underlying elements as being essentially physical, rather than neutral in character. However, since both acknowledge that physical science only studies the structural (i.e. causal), rather than intrinsic (i.e. mental), properties of these elements, this assumption seems somewhat ad hoc since there is no reason to think of the physical realm as extending beyond the domain of causal phenomena. Stoljar’s (2001a: 313) appeal to the physical properties of objects (‘o-physical’) as opposed to those of physical theory (‘t-physical’) is similarly problematic since such properties are either causal, and therefore relate to structural and not intrinsic properties, or else they are mental, in which case they cannot obviously be classed as physical. Such ‘non-materialist physicalism’ may be contrasted with Russell’s overtly neutral monist account in which the underlying entities are described as being neither mental nor physical in nature, which is the approach I have taken here.6 Terminological differences aside, however, the structure of all of these accounts is substantially equivalent since they each posit that the intrinsic properties of the underlying elements are unknown to physical science, and that these correspond — either individually or in appropriate configurations — to mental phenomena.7 Although positing the existence of an entirely novel type of ‘substance’ about which we know very little might seem to count against the theory, this is offset by the considerable philosophical advantages of the position in explaining the nature of the connection between mental and physical phenomena (although presumably we do know something about its intrinsic nature, since this constitutes the basic elements of experience).8 In support of the position, many thinkers such as Lewis (forthcoming) and Jackson (1988) have found it plausible that the intrinsic nature of the universe cannot be accounted for by the laws of physics alone, thus presenting a prima facie case for the adoption of a neutral monist position.
Expressed within the framework of neutral monism, then, Maxwell’s argument proceeds as follows. Being a particular phenomenal event — e.g. seeing a red patch or feeling a particular pain — is an intrinsic, and therefore essential, property of the relevant neutral element(s). Conversely, being a particular physical event is a structural property of the relevant neutral element(s), and is therefore contingent, since causal structures are not intrinsic to these elements, but multiply realisable through different causal networks which possess the same structural properties. Now the analogy with heat and molecular motion runs precisely in reverse to Kripke’s example, since being a particular brain event is a contingent physical property of the neutral elements which instantiate the relevant brain event in the actual world, whilst being a particular pain is an intrinsic, and therefore necessary, property of the very same neutral elements. This preserves the necessity of identity since such identities hold between two different ways of designating the same neutral elements in this, the actual world, with the physical term (e.g. ‘C-fibres firing’) picking them out by means of a contingent causal property, and the mental term (‘pain’) via a necessary property. The apparent contingency of such identities is explained by the fact that the physical property of being a brain event can come apart from the relevant neutral elements in other possible worlds that have the same causal structure — and therefore the same physical properties — but different intrinsic or phenomenal properties. Or, to paraphrase Maxwell (1978: 380), ‘a given brain event [qua neutral element] might not have been a brain event [qua causal role]’ (original emphasis). Thus there is a possible world in which the neutral element(s) that constitute each pain in the actual world play a different causal role, and so no longer constitute the same — or indeed any — brain event, although the identity between the pain and the actual causal-physical role of these elements remains a necessary one, since they are identical in all worlds where both exist.
Neutral monism therefore explains the apparent contingency of mind–brain identity statements in a manner that exactly parallels the approach that Kripke discounts. However, instead of explaining the ‘illusion of contingency’ in terms of mental events being picked out via one of their ‘accidental’ properties — something that both sides agree is impossible, or at least very implausible (ibid. 375; Kripke 1980: 330) — it is brain events that are picked out by an ‘accidental’ property; namely the property of being a brain event, which is contingent to both the mental and brain events in question (a possibility that Kripke finds ‘self-evidently absurd’ [ibid.]). The metaphysics of neutral monism explains how both of these terms can pick out precisely the same neutral element(s), making it a true mind–brain identity thesis. Physicalism, on the other hand, still turns out to be false, since the underlying entities are (pace Maxwell and Stoljar) not physical but neutral in character. This amounts to a rejection of Kripke’s assumption that physical descriptions are rigid designators since, according to neutral monism, they pick out different entities in different possible worlds by means of their contingent causal role, thereby escaping CA.9
IV. Objections
The plausibility of the above response rests largely upon the plausibility of neutral monism generally. Perhaps the most serious objection to the view, and to identity theses in general, is what Maxwell (1978: 392) calls the ‘grain objection’. If mental events are identical with brain events (or the corresponding neutral elements that comprise or subvene them) then, according to Leibniz’s Law, the properties of any brain event must be identical with the properties of the neutral elements, since they are one and the same thing. But whilst ‘the occurrence of a smooth continuous patch of red in our visual experience’ (ibid.) exhibits both unity and smoothness, it is difficult to imagine how the relevant neutral element(s) or brain event could also possess these properties, since they may be comprised of discrete, logically separable elements. Stoljar (2001a) presents a convincing response to this objection by drawing a distinction between the properties of the contents of an experience, or how that experience represents the world as being, which may be unified and smooth, and those of the experience itself, which may not.
Another potentially more pressing concern for the neutral monist is whether mental events are the sort of thing that can be comprised of intrinsic, non-relational properties at all. Whilst neutral monism does not necessarily entail the existence of so-called ‘free-floating’ qualia — one of the common historical objections to it (Stubenberg 2005) — it seems plausible that many types of experience, and therefore many mental events, are intrinsically relational in a manner that neutral monism fails to capture. Perceptual experience, or the kind of switching scenarios considered by Burge (1979; 1988), show that the contents of thought or experience cannot be captured internalistically, but incorporates elements of the surrounding environment or context. In order to accommodate this insight, the neutral monist would either have to posit that the underlying neutral elements are also externalistically individuated, which would make it difficult to identify them with a particular physical event via its causal role, or else invoke Stoljar’s distinction between representational content, which would be relational, and phenomenal experience, which would not. Both views are problematic and, whilst it lies outside the scope of this essay to explore these problems in greater detail, either may threaten to undermine — or at least complicate — the neutral monist account.
V. Conclusion
I have argued that the metaphysical doctrine of neutral monism provides a successful response to Kripke’s version of CA concerning the apparent contingency of mind–brain identity statements. Furthermore, the structure of this response closely mirrors Kripke’s own analogy with other scientific identity statements, such as ‘heat = molecular motion’ and ‘water = H2O’, but reverses the direction of the analogy such that ‘pain’ is analogous to ‘molecular motion’ and ‘C-fibre firing’ to ‘heat’, rather than (as Kripke assumes) the other way around. This explains both the apparent contingency of the resulting identity statements, and their necessity, as required by Kripke’s modal semantics. The resulting mind–brain identity thesis is, however, non-physicalist, since the bearers of the relevant properties are not physical in any ordinary sense of the term, although the structure of this account closely resembles Maxwell and Stoljar’s ‘non-materialist physicalism’. Its plausibility, however, depends upon that of neutral monist metaphysics as a whole, and whether this adequately reflects the relational nature of experience and representational content. In spite of these concerns, however, neutral monism offers a powerful and flexible framework for explaining the relation between mind and body — a problem that has been a recurrent theme in philosophy ever since Descartes’s Meditations.
——————
1 For brevity, I shall talk only of events, but the argument should be taken to apply equally to processes, states and other mental or physical entities.
2 Chalmers (2006) argues more explicitly for this link.
3 Although depending upon how philosophical works are individuated, it may be an essential property of Naming and Necessity that it was written by Saul Kripke.
4 The philosophical position known as structuralism denies that there are (or that we have knowledge of) any such underlying entities (Ladyman 2008).
5 This is not to say that every neutral element constitutes a phenomenal property, merely that some do — perhaps as a result of multiple elements combining in the appropriate manner (cf. Mach 1886). This avoids Chalmers’s charge of panpsychism, which is by no means a necessary consequence of neutral monism (Stubenberg 2005).
6 Russell’s adoption of ‘events’ as the fundamental ontological category is not essential to the position.
7 I will remain agnostic on the question of whether percepts are individual or groups of neutral elements, as per Russellian and Machean monism, respectively (see Stubenberg 2005: §5.1).
8 The suggestion that such knowledge is unattainable corresponds to Colin McGinn’s (1989) ‘mysterianism’.
9 Whether this argument allows for the existence of ‘zombies’ largely depends upon how the relationship between mental events and neutral elements is spelled out. However, such creates are at least a logical possibility on the neutral monist view.

Bibliography
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————— 1988: ‘Individualism and Self-Knowledge’, Proceedings of the Aristotelian Society, 85 (11), pp. 649–63.
Chalmers, David J. 1996: The Conscious Mind. Oxford: Oxford University Press.
————— 2002: Philosophy of Mind: Classical and Contemporary Readings. Oxford: Oxford University Press.
————— 2004: ‘The Foundations of Two-Dimensional Semantics’. In Two-Dimensionalism, M. Garcia-Carpintero and J. Macia (eds.). European Review of Philosophy. URL = <consc.net/papers/foundations.html>
————— 2006: ‘The Two-Dimensional Argument Against Materialism’. In The Character of Consciousness. Oxford: Oxford University Press.
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————— 1980: Naming and Necessity. Oxford: Blackwell.
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Is Red a Recognitional Concept?

Sat, 31 May 2008 18:55:47 +0100

Jerry Fodor and Christopher Peacocke on the theory of concepts
I. Introduction
One might think that if any concept could be considered recognitional — i.e. individuated at least in part by its recognitional properties — then the concept of red could. Not so, according to Jerry Fodor (1998a; 1998b), who rules out the existence of such epistemically individuated concepts in favour of his own informational semantics based account. This essay evaluates an alternative account of recognitional concepts by Christopher Peacocke (1992; 2000; 2005), one of the main proponents of the epistemic approach, along with some of Fodor’s objections to it. In Section II, I set out the main points of Peacocke’s theory, including the possession conditions that he specifies for <red>.1 In Section III, I evaluate Fodor’s main criticism of this account, namely that it fails to account for compositionality; i.e. our ability to grasp complex concepts like <red apple> by understanding their constituent concepts, i.e. <red> and <apple>, due to the difference between an object’s forming part of the extension of a complex concept and being a ‘good instance’ of it (Fodor 1998b: 10). Finally, in Section IV, I present Peacocke’s response to these criticisms before finally concluding that <red> is, after all, a recognitional concept, subject to some further philosophical and metaphysical concerns.
Before addressing the details of Peacocke’s theory, it is necessary to clarify the relevant notion of a concept. In contrast to the everyday usage of this term, the philosophical notion of a concept is that of a basic constituent or element of thought or language from which propositional (and possibly perceptual) content is comprised. This covers not only types, such as <apple>, <fish>, <water> etc., but connectives, qualities, relations, demonstratives, indexicals and proper names, to mention but a few. Concepts may be simple, e.g. <animal>, or complex, e.g. <pet fish>, in virtue of being linguistically and semantically analysable into their constituent concepts, e.g. <pet> and <fish>, plus a suitable mode of composition — in this case predication.2 In addition to accounting for such systematic compositionality, Fodor and Peacocke agree that any theory of concepts must respect Evans’s (1982: 100–5) Generality Constraint; i.e. that any subject who is capable of thinking that a is F, where F indicates some concept possessed by the subject, must also be capable of thinking that a is G, where G is any other concept of which the subject can conceive. For example, nobody who is able to grasp the sentence ‘the car is red’ would be unable to grasp ‘the car is green’ or ‘the apple is red’, provided that they possess the concepts <green> or <apple>, respectively (cf. Peacocke 1983: 1). Conversely, any loss of the ability to understand these concepts would result in a corresponding systematic loss of the ability to entertain propositions within which they feature (Evans 1982: 102).
Fodor (1998b: 1) defines a recognitional concept as any concept that (i) ‘is at least partly constituted by its possession conditions’ and (ii) whose possession conditions include ‘the ability to recognize at least some things that fall under the concept as things that fall under the concept’. In other words, a concept which is partially defined or individuated by the sensitivity of subjects to recognise instances of that concept. I will examine how this definition applies to Peacocke’s account of <red>, whose possession conditions involve the exercise of precisely such an ability, in Section III after setting out the main features of his account below.
II. Peacocke’s Theory
According to Peacocke, concepts are individuated by their possession conditions. That is, a concept’s identity conditions, i.e. what makes it that concept rather than another, are fixed by the conditions that determine whether a subject possesses the concept, rather than — as has traditionally been assumed — the other way round (Peacocke 2000: 328). In many cases, including the logical constants (&, ∨, →, etc.), these conditions simply list the set of inferences that the subject finds ‘primitively compelling’ (Peacocke 1992: 6), thus explaining the connection between a subject’s possessing a concept and the rational (i.e. truth-preserving) inferences that it permits them to make (Peacocke 2005: 170). Indeed, Peacocke rightly considers this to be an important task for any theory of concepts and rationality. Possession conditions may, however, involve conditions other than a concept’s inferential role (Peacocke 1992: 7). Peacocke specifies the possession conditions for <red>, for example, in terms of a thinker’s having the following dispositions:
‘[T]o believe a content that consists of a singular perceptual-demonstrative mode of presentation m in predicational combination with C when the perceptual experience that makes m available presents its object in a red′ region of the subject’s visual field […] in conditions he takes to be normal, and [where] he takes his perceptual mechanisms to be working properly.’
To form the appropriate belief as to why m is so presented.
To believe of other objects that are capable of causing the kinds of experience necessary for (1), but which are not presented to the thinker, that they are C.
where C is satisfied by the abstract object <red> (ibid. 7–8).
The first of the above conditions does the bulk of the work by specifying <red> in terms of its combination with the Fregean ‘mode of presentation’ that arises when the subject sees an object in such a way that the experience exhibits the phenomenal property of redness (red′) within their visual field. At first glance, this mention of red′ in (1) might appear to be circular, since it defines the concept red in terms of a subject’s having a visual experience of red. However, since the analysans (<red>) is a concept and the analysandum (red′) a phenomenal property, Peacocke escapes the obvious circularity by defining the concept red in terms of the property red′, which he takes to be conceptually and experientially prior to <red>. Indeed, Peacocke argues that provided the concept being analysed does not appear within the scope of a ‘that’ clause specifying the content of a propositional attitude held by the subject, it is perfectly legitimate for its definition to mention that concept without fear of circularity (ibid. 9). He justifies this by pointing out that it would be unnecessary for a subject to already possess the concept of red in order for them to meet the above possession conditions, since red′ is taken to be a feature of normal human experience (ibid. 8). Whether there are any such phenomenal properties and whether they can be individuated without reference to the corresponding concepts, however, remain important questions for Peacocke’s account, as Fodor (1995: 32) points out, although this issue does not form the focus of the dispute between them. Peacocke’s theory is, in any case, flexible enough to allow the phenomenal property red′ to be replaced by a suitable reference to the metaphysical property, red, in keeping with Fodor’s (1998a: 73) own information theoretic approach.
Another notable feature of (1) is that it references a set of normal conditions, including the proper functioning of the subject’s visual faculties. This rules out someone’s possessing <red> as a result of, for example, direct electrical stimulation of their brain, or by sensations experienced in non-standard lighting conditions. Interestingly, Peacocke’s account does not actually require the conditions to be normal, but merely that the subject takes them to be so. This is presumably to avoid any circularity that would result from the concept’s possession conditions referring to the experience of a typical subject, which would itself require the same condition to be satisfied, and so on ad infinitum. However, the fact that the experience must be one of red′ is already sufficiently normative to avoid the generation of bizarre counterexamples that take advantage of this discrepancy. That what constitutes ‘normal conditions’ is an epistemic rather than metaphysical condition, and so may vary between one concept and another, will become important when considering how such conditions apply to cases of compositionality.
Conditions (2) and (3) qualify (1) by requiring that the subject be disposed to identify (where appropriate) the cause of his experience as being due to seeing something ‘red’, even for objects that are not, or may never be, visually present. Whilst Peacocke does not spell out the precise content of the relevant belief in (2), it presumably relates to the subject’s having seen a red-looking object, or perhaps the properties of the object that cause it to give rise to the phenomenal experience of red′. Here, as in (1), circularity would be avoided by mentioning the concept via the variable C, since any further use of <red> would fall foul of Peacocke’s restriction upon the concept appearing within the scope of a propositional attitude clause, as described above. In the case of subjects who are not capable of forming such beliefs since they lack the requisite cognitive faculties, e.g. young children or lower animals, Peacocke argues that it is sufficient that they would be disposed to form such beliefs were they to acquire the requisite faculties — as is the case with older children, for example. This is something of a moot point in the case of animals since there is no way to test the hypothesis, but it serves to emphasise the fact that Peacocke’s account of <red> is essentially dispositional, and does not require the subject to form the relevant belief in every case, or even to be capable of representing predicate structure (cf. Peacocke 1992: 8). Condition (3) caters for the fact that unobserved objects may also be red, since causing red′ sensations is a sufficient, but not necessary, condition for redness. If this condition were omitted then it would lead to the obviously implausible conclusion (pace Berkeley) there are no unobserved or unobservable red objects as a matter of a priori necessity (ibid. 20).
According to Peacocke, (1) through (3) constitute the complete set of possession conditions for <red>, and thereby individuate the concept. In order to determine whether something is red or not, a subject must exercise the epistemic capacities specified within these possession conditions, such as judging whether an object is presented in a red′ region of their visual field, thus enabling them to assign the appropriate semantic value (e.g. true or false) to propositions that involve <red>.3 The way in which the semantic value of a concept may be derived from its possession conditions is known as its ‘determination theory’ (ibid. 17). Although the details of this theory may vary according to the concept in question, it will in each case be both consistent with, and permit the subject to form true beliefs or inferences in accordance with, that concept’s possession conditions (ibid. 19).4 The correct exercise of the epistemic capacities specified by the determination theory for <red>, along with the state of the world at some particular time, will thus yield a true judgement as to, for example, whether or not some particular object is red. In this way, the semantic and empirical content of a concept is defined by a combination of its possession conditions plus the appropriate determination theory (ibid. 17).
The main strength of the above theory is undoubtedly its ability to explain the close connection between the possession a concept and the truth-preserving inferences that it enables a rational subject to make, since the two are, on Peacocke’s view, fundamentally interrelated through the concept’s possession conditions (see Peacocke 2000: 332). This in turn explains how the acquisition of a new concept enables a subject to carry out a wide range of valid inferences involving that concept, as the Generality Constraint requires, as well as the essential role that concepts play in our general ability to think and reason. However, Peacocke’s theory ties the possession conditions and determination theories of most (if not all) concepts to the epistemic or recognitional capacities of a rational subject. It is this aspect of the theory to which Fodor takes exception, causing him to rule out the existence of any such recognitional concepts — including <red>.
III. Fodor’s Critique
Before addressing the main thrust of Fodor’s critique, it will be useful to examine precisely how the above account relates to the definition of a recognitional concept given in Section I. Since the possession conditions for <red> involve only dispositions to form <red>-beliefs, whereas Fodor’s definition requires the ability to recognise things that fall under the concept as being red, it could be argued that <red> is not a recognitional concept, since (i) a subject may fulfil the relevant possession conditions without actually forming the belief that some object is red, and (ii) subjects need not possess the cognitive capacity required to form the relevant beliefs, as described above in the case of animals or young children. In general, however, the disposition to form <red>-beliefs under the circumstances specified by (1) does presuppose the ability to recognise red objects in virtue of the phenomenal property that they cause within the subject’s visual field. Since Fodor is opposed to any reference to epistemic capacities in explaining what ‘constitutes’ such concepts (Fodor 1995: 31), Peacocke’s definition clearly falls within the spirit, if not the letter, of the above definition.
Turning to the the main point, both Peacocke and Fodor take it that compositionality — i.e. the ability of rational subjects to grasp complex concepts simply in virtue of grasping their constituent concepts — is an essential (although not sufficient [Peacocke 1983: 55]) feature of concepthood, and something that any successful theory of concepts should explain. Fodor claims that Peacocke’s theory is unable to do this for the following reason. A subject who grasps <red> and <apple>, along with the predicational mode of composition, should thereby be capable of grasping the complex <red apple>. Conversely, a subject who grasps <red apple> must, ipso facto, be in possession of its constituent concepts, namely <red> and <apple>.5 Fodor argues that this cannot be the case for recognitional concepts since the relevant epistemic capacities do not compose in the required manner. What it takes to recognise a ‘good instance’ of <red apple>, he argues, may well differ from what it takes to recognise ‘good instances’ of <red> and <apple>, meaning that the ability to recognise instances of the former concept cannot be ‘inherited’ from an understanding of the latter (1998b: 10). It would therefore be possible for a subject who grasped both <red> and <apple> to nevertheless fail to satisfy the possession conditions for <red apple>, since they lack the relevant recognitional capacity, thereby contravening the principle of compositionality.6
As Peacocke (2000: 337) points out, Fodor’s own example of <pet fish>, whilst dialectically appealing, does not constitute a counterexample to Peacocke’s theory of recognitional concepts since neither <pet> nor <fish> is plausibly recognitional. Nevertheless, the objection generalises since every putatively recognitional concept may be combined with other non-recognitional concepts to form other complex concepts — e.g. <red hair> — to which a similar objection would apply. Although the resulting concept may be non-recognitional, its possession conditions arguably do not include the recognitional ability for red′, since red hair is not literally red, but rather reddish — or, to put it another way, red for hair (cf. ibid. 338). As such, the principle of compositionality appears to have been violated unless another explanation for the discrepancy can be found.
Peacocke responds to this objection by citing two kinds of cases in which the above situation can occur, but which nevertheless do not constitute a counterexample to the compositionality (ibid.). The first involves cases where the possession conditions for a non-standard mode of composition — in this case <for> — must also be taken into account. In order for a complex concept to be recognitional, each of its components must also be recognitional. Since <for> is not a recognitional concept, any complex concept, such as <red hair>, that involves it will also be non-recognitional, even if all of its other constituents (i.e. <red> and <hair>) are recognitional. In such cases, any additional epistemic content comes from applying the determination theory of the relevant mode of composition (i.e. <for>), and not from the fact that semantics ‘runs a barber shop’, as Fodor (1998b: 10) mischievously suggests. The possession conditions for <red hair> will, therefore, include the relevant elements of (1), but in a modified form due to their having been ‘multiplied out’ (Peacocke 2005: 173) — i.e. combined according to their semantic content, rather than simply being listed as a set of criteria — by the possession conditions for <for> and <hair>. The resulting non-recognitional concept can therefore be grasped by the possession conditions of its constituent concepts, as compositionality requires, even though its instances will not necessarily be recognisable this way.
The second way in which Peacocke suggests that complex concepts and recognitional abilities can come apart concerns what constitutes the normal conditions for recognising instances of each concept. Even in cases where the mode of composition is straightforwardly predicational, as with <red apple>, the conditions conducive to recognising, for example, red things (or apples) may plausibly differ from those conducive to the recognition of red apples. This may sound like a mere restatement of Fodor’s original objection in the <pet fish> case in that it involves a situation where the possession of a recognitional ability for each of the constituent concepts appears to be insufficient for recognising instances of the complex concept. However, this problem does not arise at the level of possession conditions, since the relevant conditions, e.g. (1), do not specify precisely what constitutes the normal conditions for recognising instances of that concept, but rather appeal to the independent knowledge of the thinker, as previously noted. Moreover, it may — in principle, at least — be determined in advance whether the conditions for recognising instances of the relevant constituent concepts are in fact compatible, and thus whether the resulting complex concept will be recognitional or non-recognitional. In the former case, where the normal conditions are compatible, the compositionality of both possession and recognition conditions will be respected, and so the relevant epistemic capacities will compose. In the latter, the resulting concept will be non-recognitional, and so does not present a counterexample to the principle of compositionality for recognitional concepts (Peacocke 2000: 339).7
Peacocke’s response to Fodor is therefore that, barring special cases that arise from the use of non-predicational modes of composition and conflicting recognition conditions, all simple recognitional concepts, when combined with other recognitional concepts or modes of composition to form complex recognitional concepts, obey the principle of compositionality (ibid. 340). Furthermore, even in these special cases, the possession conditions of such concepts (including the relevant mode of composition) combine in such a way that the compositionality of the relevant concepts’ possession conditions is respected. It is therefore essential to Peacocke’s theory that there are no cases in which a complex concept’s possession conditions do not contain each element of its constituent concepts’ possession conditions, since such a case would represent a counterexample to the theory. This is, perhaps difficult to evaluate in the absence of specifications for the possession conditions of many everyday concepts — something that Peacocke can justifiably be criticised for failing to provide, and which Fodor is doubtful could ever be achieved in practice (Fodor 1995: 31). Whilst this may count against Peacocke’s theory of concepts in general, in the absence of any convincing counterexample, it seems at least plausible that this should be the case, particularly with regard to recognitional concepts, such as <red>, for the reasons given above.
IV. Conclusion
I have argued that <red> is a recognitional concept since, on Peacocke’s account at least, its possession conditions plausibly involve the exercise of epistemic capacities, such as the ability to recognise red′ regions of one’s visual field. One consequence of this account is that it requires the existence of such phenomenal properties or sensations as red′, along with those ‘primitively compelling’ inferences that define the logical constants and other non-recognitional concepts. This may seem metaphysically extravagant since the properties and inferences in question mirror the very concepts that such a theory might itself be expected to explain. This objection is not, however, decisive since even rival non-epistemic theories, such as Fodor’s own account, must posit the existence of suitable metaphysical properties to which each of our concepts refer, and so have comparable (although different) ontological commitments.
Fodor’s criticism of the ability of Peacocke’s theory to account for compositionality is unsuccessful since the possession conditions that individuate recognitional concepts such as <red> do in fact compose, provided that the relevant mode of composition is taken into consideration (although whether the same applies to other non-recognitional concepts remains undecided). The theory also explains our ability to apply new concepts in conjunction with, for example, demonstrative concepts in accordance with Evans’s Generality Constraint, which is itself derivable from Peacocke’s theory that concepts are individuated by their possession conditions (Peacocke 1992: 48). Indeed, such demonstrative concepts arguably form an important class of recognitional concepts in their own right. Perhaps a more damaging and fundamental objection to this theory arises from Quine and Fodor’s rejection of the analytic–synthetic distinction (Fodor 1995: 33–4). However, since this issue lies beyond the limited scope of this essay, I conclude — for present purposes at least — in favour of the intuitively plausible view that <red> is, after all, a recognitional concept.
——————
1 Concept names are enclosed within angle brackets such that <red> denotes ‘the concept red’. The terms red′ and red refer to the corresponding phenomenal and metaphysical properties, respectively (adapted from Peacocke 1992: 7).
2 This differs from the Fregean notion of a concept as the referent of an ‘unsaturated’ predicate; e.g. ‘______ is red’ (Frege 1892).
3 Indeed, for Peacocke, a subject’s possessing a concept is just a matter of their knowing what it is for something to be its semantic value — an equivalence he refers to as ‘the Identification’ (ibid. 23).
4 Elsewhere Peacocke (2005: 171) talks of a concept’s semantic dimension (i.e. its truth values) being ‘recoverable’ from its cognitive dimension (i.e. its possession conditions), and vice versa.
5 Note that a subject could possess a simple concept with the same extension as <red apple> — call it <rapple> — without satisfying the possession conditions for <red> and <apple>. However, since <rapple> is arguably a different concept from <red apple>, which, by stipulation, has complex semantic structure, such cases do not constitute counterexamples to the principle of compositionality.
6 Fodor’s (1998a: 74) own view is immune to this objection since he takes it that relations between concepts occur at the metaphysical level of properties in the world as opposed to the epistemic level of possession conditions, as on Peacocke’s account.
7 One might object that even in these cases, compositionality must be preserved, but provided that the possession conditions make is possible to grasp the complex concept in virtue of its constituent concepts, the subject need not be able to recognise instances of a non-recognitional concept.

Bibliography
Fodor, Jerry A. 1995: ‘Review of Christopher Peacocke’s A Study of Concepts’. In In Critical Condition. Cambridge, Massachusetts: MIT Press (1998), pp. 27–34.
————— 1998a: Concepts: Where Cognitive Science Went Wrong. Oxford: Oxford University Press.
————— 1998b: ‘There Are No Recognitional Concepts; Not Even RED’. Philosophical Issues 9: 1–14.
Frege, Gottlob 1892: ‘On Concept and Object’. In The Frege Reader, M. Beaney (ed.), Malden, MA: Blackwell Publishing, pp. 181–93.
Peacocke, Christopher 1983: Sense and Content: Experience, Thought and their Relations. Oxford: Clarendon Press.
————— 1992: A Study of Concepts. Cambridge, Massachusetts: MIT Press.
————— 2000: ‘Fodor on Concepts: Philosophical Aspects’. Mind and Language, 15 (2), pp. 327–40.
————— 2005: ‘Rationale and Maxims in the Study of Concepts’. Noûs, 39, pp. 167–78.
Recanati, François 2002: ‘The Fodorian Fallacy’. Analysis, 62 (276), pp. 285–89.

Direct Realism and Visible Figure in Reid

Wed, 16 Apr 2008 15:04:32 +0100

Is Reid’s conception of visible figure compatible with his direct realism about perception?
I. Introduction
According to the theory of perception set out in Thomas Reid’s Inquiry into the Human Mind on the Principles of Common Sense (ihm, Reid 1997) and Essays on the Intellectual Powers of Man (eip, Reid 1865), our perceptual knowledge of objects in the external world is both epistemically direct and non-inferential. Whilst there has been much debate about the precise nature of Reid’s realism (e.g. Buras 2002; DeRose 2004; Copenhaver 2000, 2004; Pappas 1989) and whether it can be properly described as direct, one aspect of his account remains poorly understood, namely his account of visual perception. According to Reid, the ‘immediate objects of sight’ (ihm 102) are not macroscopic objects in the external world, as for each of the other four senses, but what Reid variously describes as ‘visible or perspective appearance[s]’ (ihm 81), ‘apparent figure[s]’ (ihm 82) and, most commonly, ‘visible figure[s]’ (ihm 95–103). In this essay I will examine the precise nature of these entities and whether they undermine Reid’s direct realism since, if the immediate object of perception is also the direct object, then this appears to conflict with the thesis that we have direct access to objects in the external world by means of visual perception.1
In order to motivate my argument, I will first give a brief summary of Reid’s theory of perception, followed by an account of his notion of visible figure. I will then consider the philosophical basis for Reid’s direct realism and how this might be undermined by the existence of visual intermediaries. Finally, I will argue that it is possible for Reid to maintain his commitment to direct realism in spite of the non-immediate nature of visual perception on the grounds that visible figure is related to and derivable from the real qualities of objects. In doing so, I will present an interpretation of Reid’s theory that highlights the role of his ‘doctrine of signs’ — an element of Reid’s philosophy that is often overlooked, but which, I argue, plays a more central part in his account of visual perception than might first appear.
II. Sensation and Perception
In contrast to the so-called ‘theory of ideas’ (eip 111) held by Descartes, Locke and Hume, amongst others, Reid rejects the notion that the objects of perception are mere ‘ideas’ or impressions within the mind in favour of a direct realist theory of perception. According to Reid, the object of perception, what I shall call its intentional content, is not some ‘idea’ or impression within the mind, but the object or objects in the external world that we normally take the perception to be about. Moreover, the conception and belief arising from sensory experience, and that is not, for Reid, the result of an inferential or rational cognitive process. Instead, the mind is said to proceed immediately from the ‘sign’ of an external object — e.g. a sensation of touch or smell — to what is ‘signified’, i.e. the object itself, thus placing us in direct epistemic contact with the external world. This may be contrasted with, for example, Hume’s (1737: 1.1.1) account, which leaves an ‘epistemic gap’ between the immediate objects of perception — in Hume’s case, impressions in the mind — and those in the external world, thus creating the possibility of the sort of systematic scepticism that Reid considered to be so abhorrent to common sense (ihm 28).
Central to Reid’s account is the distinction between sensation and perception — a distinction which he was chiefly responsible for defining (Price and Gibson in van Cleve 2003: 104). For Reid, a sensation is a ‘simple act of mind’ that ‘accompanies’ perception (eip 15) and whose character is open to rational reflection — or what contemporary philosophers might call a ‘raw feel’ or quale. The archetypal example of a sensation concept is that of pain where the subject is conscious of a certain feeling, but not of any particular object that the feeling is about; i.e. it has no intentional content (although it will of course have some internal or external cause). Whether by virtue of our constitution or through association by means of experience, sensations function as ‘signs’ of the internal or external states that occasion them. Thus, in contrast to so-called sense-data theories of perception, they do not acquire meaning through any intrinsic ability to bear information, but rather stand in extrinsic relations to the external events that they signify (Copenhaver 2004: 71–2). Perception, on the other hand, is comprised of what Reid calls ‘conception and belief’ (ihm 168), and is the bearer of intentional content (ibid.). For Reid, the perception — of a seagull, for example — is about its object (the seagull) in a way that the sensations of sound and colour that accompany it are not.2 Reid’s notion of ‘conception’ is subtle and complex,3 but his intention is to distinguish between what is felt and what is perceived, with the intentional content of perception always being some object or objects in the external world rather than an ephemeral ‘idea’ or sense-impression as per the theories of Descartes and Hume.
Reid explicitly states that sensations are not themselves objects (except in the trivial grammatical sense; ihm 167–8), but rather aspects of the act of perceiving that have ‘no distinction from the act of mind by which [they are] felt’ (ibid.). Thus, ‘feeling a pain has no more significance than being pained’ (ihm 108; original emphasis).4 This has led some commentators (e.g. Pappas op. cit: 162 and van Cleve op. cit: 104) to take Reid as advancing a kind of adverbialist theory of sensation, although this is perhaps an overstatement since his account is motivated mainly by epistemic and phenomenological concerns, and lacks the necessary ‘systematic structure’ for full-blown adverbialism (Nichols 2007: 85). Nevertheless, it is crucial to Reid’s direct realism that he does not classify sensations as objects since this would make them the direct objects of perception, as per the theory of ideas, instead of external mind-independent objects. Were this the case, then we could no longer be said to be in direct epistemic contact with the external world, thus undermining Reid’s primary argument in favour of realism and against scepticism. This is particularly relevant in the case of visual perception, whose only sensory component is that of colour (ihm 99), with the rest of what is seen being explained in terms of Reid’s notion of visible figure. Unlike sensation, however, visible figure is described as being both objective and mind-independent (Nichols op. cit: 122), and is therefore, even by Reid’s own admission, the ‘immediate object’ of visual perception (ihm 102).
III. Visible Figure
A sizeable part of Chapter VI of Reid’s Inquiry (§§7–19) is devoted to describing the non-Euclidean geometry of visible figure, as established by empirical and geometrical study. This in itself is quite remarkable given that the necessary mathematical formalism would not yet be developed for another hundred years by German mathematician Bernhard Riemann (Torretti 2007). Reid describes visible figures as ‘real and extended object[s] to the eye’ (ihm 101), differentiating them from both the ‘real’ (i.e. actual) figures of objects (ihm 96) and from sensations, for the following reasons:
Visible figure contains representational structure concerning ‘the position of [an object’s] several parts with regard to the eye’ (ibid.), unlike sensation whose significance is extrinsic to its content, as described above.
Any competent perceiver looking from a particular point of view and direction would perceive the same visible figure (ihm 84–5; Nichols op. cit: 122), thus making visible figure an objectively accessible feature of reality rather than a subjective act of mind as in the case of sensation.
Visible figures have both form and extension, and thus resemble their objects (ihm 98). Sensations, which are mental, are incapable of extension — as established by Berkeley (ihm 90–5) — and have ‘no direct object distinct from the act [of mind] itself’ (eip 19).
Visible figure may be derived mathematically by projecting ‘right lines’ (ihm 96) from the surfaces of objects to the part-spherical surface of the perceiver’s retina. This procedure may even be carried out by someone who is blind,5 making visible figure, unlike its tactile, auditory, olfactory and gustatory equivalents, accessible to those who lack the requisite sense — albeit minus the sensation of colour (ibid.).
For these reasons, Reid concludes that visible figure ‘cannot be called an impression upon the mind’, i.e. a sensation, ‘without the grossest abuse of language’ (ihm 100–1).
On Reid’s account, however, visible figure does have some features in common with sensation. Like sensation, visible figure functions as a ‘sign’ for external objects which is quickly ‘passed over’ by the mind and replaced by the perception (i.e. conception and belief) of those objects (ihm 168). This is illustrated by Reid’s example of the painter (ihm 102), who creates reproductions not of objects per se but of their visible figures such that any normally sighted observer would (according to the accuracy of the likeness) immediately recognise the resulting image as a ‘sign’ of the objects depicted.6 As with sensations, visible figures may also become the objects of conscious thought. The painter, for example, trains himself to perceive visible figures directly, as opposed to the objects that are normally signified by them (ihm 83), thus making conscious what is usually ‘passed over’ by the mind to such an extent that ‘it never had a name in any language’ prior to Berkeley (ihm 101).
Despite the above similarities, however, the lack of any compelling phenomenological evidence for a distinct sensation associated with vision (other than that of colour, which is uncontroversial) leads Reid to conclude that it is visible figures, not everyday objects, that are the immediate objects of our visual perceptions. This makes sight unique amongst the five senses in that it is the only one to not have everyday macroscopic objects as its intentional content. This appears to place Reid’s notion of visible figure in conflict with his direct realism since, if the immediate object of perception is also taken to be the direct object of perception, our epistemic access to the world by means of vision must also be indirect since, by Reid’s own admission, it is mediated by visible figure. Nichols (op. cit: 109) has suggested that this tension may represent a deliberate trade-off between the parsimony and explanatory power of Reid’s theory, or that he may even have been unaware of its full implications (ibid. 111). However, this is implausible since Reid would hardly have advanced an account that was so obviously guilty of the error for which he rejects the theory of ideas. In order to examine this claim more closely, we must therefore establish the precise nature of Reid’s direct realism.
IV. Direct and Indirect Realism
George Pappas (1989: 156) identifies two distinct forms of direct realism to which Reid subscribes: ‘perceptual direct realism (PDR)’ and ‘epistemic direct realism (EDR)’ (ibid.). According to PDR, external objects exist independently of the perceiver and are the bearers of at least some of their perceived qualities — typically the primary qualities of figure and extension. PDR therefore accounts for the realist aspect of Reid’s theory. EDR, on the other hand, entails that we have immediate non-inferential belief about such objects — a position that Reid clearly endorses throughout the Inquiry (e.g. ihm 81, 168, 172). It is this condition of immediacy within PDR that is called into question by Reid’s notion of visible figure, and that threatens to undermine his direct realism. Whilst it is relatively trivial to define ‘direct’ in such a way that Reid comes out as a direct or indirect realist according to the chosen definition, a more pressing question is whether PDR really does require the ‘immediacy’ of visual perception. It is therefore important to ascertain the relationship between immediacy and directness in Reid’s account, as well as the precise meaning of ‘immediate’ in this context. To this end, I will consider several means by which the intentional content of perception might be determined before moving on to examine how this process might be affected by Reid’s conception of visible figure.
We can first rule out the idea that Reid’s theory of perception involves some kind of ‘mythical’7 connection between mind and world in which there are no intervening stages whatsoever. Reid’s himself describes many mediating entities, including light rays, which communicate the visual appearance of objects to the eye, and impulses within the sense organs and nervous system (although the latter should not be identified with sensations since they occur in the body rather than the mind [ihm 100]). All forms of perception are thus mediate in some sense, and so the presence of an additional mediating entity in the form of visible figure should not necessary cause us to conclude that Reid’s theory is epistemically indirect.
Analysing perception in terms of causal relations presents a similar difficulty in that every perceptual event is itself preceded by a complex chain of events. Light strikes the surface of an object, some of which is reflected towards the eye causing an image to be formed on the surface of the retina, which in turn causes an electrical signal to be transmitted to the brain, and so on. Clearly we do not take the light (not to mention the nuclear reactions on the surface of the sun that caused it to come into existence) to be the intentional object of perception. The intentional content of perceptions must therefore be fixed by some factor other than mere causal connection. Furthermore, whilst it is tempting to assume, as per Pappas (op. cit: 160) and Buras (op. cit: 462), that Reid takes bodily impressions to be the cause of sensations, which in turn cause perceptions, Reid himself never uses this term and should not be read as such. Indeed, he points out the ambiguity of the word ‘cause’ (ihm 40), whose vulgar use signifies little more than constant conjunction, the direct perception of which had already been ruled out by Hume (op. cit: 1.3.2), regardless of whether there is any genuine efficacy. Furthermore, Reid denies any knowledge of the nature of the connection between bodily and mental phenomena, declaring it to be most ‘unaccountable’ (ihm 91). Reid’s language is rather that of occasionalism in which an external object ‘occasions’ or ‘suggests’ sensations that subsequently give rise to a corresponding perception, but without any specific account of the mechanism by which these events take place (except for the presence of the mediating entities described above).8 Reid does, however, give a clear indication of sequence, describing perception as a ‘process’ or ‘train of operations’ (ihm 174) in which sensation is ‘followed by’ conception and belief (ibid.). Whilst this might be suggestive of some as yet undiscovered causal mechanism, Reid conspicuously stops short of claiming that one stage causes the other. We should therefore be wary of attributing any substantive role to causation in fixing the intentional content of perception within his theory.
Perhaps a more productive method of establishing the intentional object of visual perception may be given in terms of a counterfactual analysis of its necessary and sufficient conditions. When I see an object — a tree, for example — this forms both the occasion for and content of my perception, thus giving rise to the conception and belief that there is a tree before me. Were the object not present then I would, by definition, be unable to perceive it — a hallucination, for example, would not count as a case of perception for Reid. The same cannot be said of sensations, since although I might not be conscious of any particular sensation that accompanies the perception — the colour of the tree, for example — I can still be said to perceive the tree. This is arguably the case with many non-visual perceptions, since I am not necessarily aware of the particular sensation of touch beneath my fingers, but rather of the table, or of the scent that is emanating from the kitchen, but of my dinner as it is cooking in the oven. Thus, although sensations may ‘occasion’ or give rise to perceptions, experiencing the sensation is neither a necessary nor sufficient condition for perception.9 Conversely, visible figure is similarly insufficient for perception since all visible figures are of some actual object or objects, without which the visible figure could not exist. Sensations do not fit this description since they are neither objects in their own right nor intentional, and may often be absent from perceptual experience. Visible figure, on the other hand, is both objective and necessary for visual perception — in humans, at least — but cannot exist independently of a particular point of view and an object. This gives us some clue as to its true nature, as I will explore in the following section. We can imagine, however, that visual perception, or something very much like it, might be possible for some creatures (although not for us) in the absence of visible figure, suggesting that it is only objects and not their visible figures that are necessary for perception to take place (cf. ihm 176; Nichols op. cit: 137).
The above considerations may be restated more clearly as the claim that there is an internal relation between an object, perceiver and visible figure such that the third cannot exist in the absence of the first. Consequently, whilst visible figure may be the ‘immediate’ or ‘direct’ object of visual perception in a strictly literal sense, it does not constitute the intentional content of the perception — i.e. the external object with which we are cognitively acquainted (van Cleve op. cit: 119) — since it cannot exist independently of that object. However, this leaves us with a puzzle. We have established that visible figure fulfils the same role in Reid’s account of visual perception as sensation does in the case of the other senses; i.e. as the ‘sign’ of some external object(s). However, it now seems as if we have two direct objects of visual perception: the ‘immediate object’ or ‘sign’ (visible figure) and the external object(s) that it signifies. Reid himself acknowledges as much, stating that
the thing signified, when it is introduced to the thought, is an object of thought no less immediate than the sign was before: and there are here two objects of thought, one succeeding another […].
eip 85 in Nichols op. cit: 196 (emphasis mine)
Whilst this duality is helpful in explaining certain types of visual phenomena, such as the way that a circular plate can appear to be both elliptical (its visible figure) and round (its actual figure) (ihm 79), or the apparently small size (visible figure) of a distant object whose actual size or figure remains constant (ihm 84), it fails to settle the issue of Reid’s direct realism since it is no longer clear which sense of ‘direct’ is operating here. In the following sections, I shall therefore examine the relation between objects, visible figures and perceivers that is central to understanding Reid’s theory of visual perception.
V. Relational Properties
As has already been established, visible figure is both the ‘immediate object’ of visual perception and mathematically derivable from the actual location and forms of external world objects relative to the eye. Whilst it is clear that, for Reid, visible figures are not sensations but objectively accessible features of the external world, it is less clear precisely what kind of features they are. Reid himself professes to be at a loss as to which metaphysical category they should belong (ihm 98), suggesting that there is something peculiar about the ontological status of visible figure as compared to concretely existing objects in the external world. According to Nichols (2002: 61), this peculiarity may properly be attributed to its relational character.
Visible figures are ‘real’ in the sense that they are reliable signs of external objects that are accessible to all visually able perceivers (unlike sensations, which are mental entities, and so private to each individual). Despite being the immediate objects of visual perception, however, their existence is dependent upon the relationship between the location and orientation of the perceiver’s eye and the external objects that fall within its view (ibid: 123). This is why even non-visually able perceivers are able to derive the properties of a given visible figure geometrically from the relation between the surfaces of external objects and the eye — a fact that is frequently emphasised by Reid (e.g ihm 95). Visible figure, therefore, belongs to the ontological category of relational properties — or, more accurately, sets of relational properties — whose existence is contingent upon that of objects and some kind of perceptual apparatus resembling the human eye; i.e. a concave spherically-shaped projection surface. This does not render visible figure mind-dependent since its properties are determined by the physical geometry of the eye (Nichols 2007: 115) rather than the conscious awareness of the perceiver. Indeed, different kinds of visible figure may be derived for different kinds of surfaces; e.g. a perfect Euclidean plane, or a centrally magnifying lens as possessed by vultures and other birds of prey (Snyder and Miller 1978). There are, in fact, an infinite number of possible visible figures for any given set of objects, only a tiny fraction of which we are able to detect with the naked human eye (cf. Nichols 2007: 119). In each case, however, such figures are derivable from the real properties of objects relative to the eye, and so both objective and mind-independent.
Having established that visible figures consist of relational properties, we might legitimately ask whether there is any evidence as to whether Reid is a realist about such properties. As Nichols (op. cit: 122) points out, Reid makes it clear that relations such as the fact that ‘my foot is longer than my finger’ (eip 293) can be perceived immediately and non-inferentially, just as for visible figure. However, whilst this lends support to the notion that visible figures are relational and gives good reason to believe that Reid is a realist about visible figure, it does little to ascertain the epistemic directness of his account of visual perception. Indeed, one might argue precisely the opposite on the grounds that if visible figures are real and external to the eye then it is they, and not the external objects that they signify, that are the direct objects of perception. To clarify this issue, we must instead turn to what I will call Reid’s ‘doctrine of signs’.
VI. Reid’s Doctrine of Signs
Throughout the Inquiry, Reid repeatedly likens the sensible and visible ‘signs’ that lead the mind to form non-inferential conception and belief to a kind of ‘visual language’ (ihm 82, 166, 190). To the modern reader, this might seem like little more than rhetorical flourish, but given Reid’s disdain for the ‘way of analogy’ (ihm 203), it seems reasonable to assume that this comparison represents an important part of his overall theory. Central to this ‘doctrine of signs’ is the idea that in recognising or ‘interpreting’ (ihm 189) a sign, the mind immediately and involuntarily forms both conception and belief concerning the thing that is signified, in this case an object in the external world. According to Reid, there are three ways in which such associations may be established: (i) innately, by virtue of our natural constitution, as in the case of colour, (ii) acquisition by custom or habit, as in the case of depth perception, and (iii) through the operation of reason (ihm 177). Once established, however, even in the case of associations acquired through habit, the transition from sign to what is signified occurs solely in virtue of our physical and mental constitution, and not through any process of logical reasoning or inference (Copenhaver 2004: 70; ihm 81). As such, the formation of new associations in cases (ii) and (iii) may be seen as a way of preparing the mind to make similar such non-inferential associations in future, as opposed to involving the acquisition of any kind of knowledge concerning the link between signs and what they signify. In many cases (e.g. sensations) we may not even be aware of the ‘sign’, which immediately gives way to an awareness of the object itself. However, since both visible and real figure may be made the direct object of perception when attended to accordingly, this creates the impression that there are two direct objects of vision. It is only when we examine the respective role of each of these objects within the perceptual process that the distinction between sign and signification becomes clear.
For Reid, visible figure therefore performs the same function in the case of visual perception as sensation does for non-visual perception; i.e. as a sign for external objects (cf. ihm 186). Thus it is not that visual perception is indirect due to by the presence of visible figure, but rather that visible figure is itself an intermediate, non-causal stage in the formation of a fully fledged visual perception. On this view, it is correct to say both that visible figure is the ‘immediate object’ of visual perception (since it is the objective entity that we initially perceive) and that visual perception is direct (since the perception of visible figure immediately gives way to the perception of external objects by means of the natural operation the mind, just as with each of the other senses).10 We can therefore make sense of Reid’s claims about the directness of visual perception by interpreting his theory within the context of his doctrine of signs. Combined with the derivability of visible figure from the relational properties of objects with respect to the eye, Reid’s claim that the former is the ‘immediate object’ of visual perception does not affect the epistemic directness of his account in any important sense. We are able to see external objects by virtue of their relational properties with respect to the eye. This perceived or visible figure then gives way to a fully-fledged conception and belief concerning the object whose existence it signifies, which then forms the direct intentional content of our perception.
VII. Problems for Reid
The above interpretation of Reid’s theory leaves him open to several further criticisms. Firstly, it is not clear that visual perception does always proceed through the distinct stages that he describes. However, since the same can also be said of each of the other four senses, this represents a more fundamental problem for Reid’s doctrine of signs than the original charge of inconsistency with respect to direct realism and visual perception. One possible rejoinder would be to claim that the mind proceeds directly to the object signified without any distinct intervening stages whatsoever, although this would conflict with Reid’s official position that perception ‘follows’ sensation and/or visible figure. Of course, it could be argued that Reid was simply wrong about this, in which case the rest of his theory stands relatively unchanged. Another response might be to interpret the distinction between the immediate and intentional objects of perception (in this case visible and actual figure) as delineating functional and cognitive aspects of perception, respectively, rather than constituting a literal description of the mechanism by which perception takes place.11 Indeed, some commentators — notably Immerwahr (1978 in van Cleve 2002) — take Reid to hold just such a ‘double-tier’ theory in which sensation and perception exist alongside one another, or where sensation forms a proper part or ‘element’ of conception and belief (e.g. Pappas op. cit: 163), as opposed to being an interim stage or by-product of the perceptual process. However, again, these interpretations run contrary to Reid’s own writing and so represent a development, rather than a defence, of his account. Perhaps the best response is simply to deny that such processes must take place at the level of conscious awareness, making Reid’s argument an empirical hypothesis about the workings of the human perceptual apparatus.
A second criticism that might be levelled at Reid is that the perception of visible figure as a sign does in fact make visual perception indirect, since it only grants us knowledge of the sign and not of the object, with which we have no direct epistemic contact. However, for Reid, it is not the initial object of perception but the intentional content of the resulting conception and belief that is responsible for the directness of perception. Furthermore, his doctrine of signs explicitly states that one is immediately and non-inferentially followed — and in many cases replaced — by the other at a subsequent stage of the perceptual process. Since intentional content is fixed by the presence of external objects and not just of visible figure, which is a purely relational entity, Reid’s account arguably manages to avoid this objection with respect to visual perception.
VIII. Conclusion
I have argued that Reid’s conception of visible figure does not undermine his direct realism about visual perception on the basis that (i) visible figure is relational, and may be derived mathematically by any rational observer, and (ii) when read in the light of Reid’s overarching ‘doctrine of signs’, the claim that visible figure is the immediate (i.e. initial) object of perception does not affect the directness of visual perception in any important sense. On this account, visible figure is a mere stage or aspect of the perceptual process, rather than an epistemically significant element of Reid’s theory. Furthermore, this often neglected aspect of Reid’s philosophy brings unity to the perceptual faculties by emphasising the role that sensation and visible figure play in the formation of perceptual experience, and the mental processes by which this is supposed to occur. As such, Reid’s treatment of visual perception is consistent with that of the sense modalities of hearing, touch, taste and smell — with the important difference that, unlike sensation, visible figure is both objective and mind-independent. This discrepancy can, however, be put down to genuine phenomenological differences between vision and the other four senses, rather than any inconsistency or oversight on Reid’s part, thus making the above a highly plausible interpretation of his theory of perception as a whole.
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1 For the purposes of this essay I will follow Copenhaver (op. cit.) in taking it that Reid is, or at least seriously considers himself to be, a direct realist, which is the reading most obviously supported by the texts.
2 For Reid, the latter are merely co-occurrent with the perception.
3 In eip Essay IV (pp. 203–44) he describes it as ‘simple apprehension’, which has cognitive but not propositional content, which is similar to McDowell’s current position (McDowell 2008).
4 Sensations may, however, become the intentional content of our thoughts via the faculty of reflection. For Reid, reflection is a matter of thought and not of perception since it has an internal, rather than external, object (eip 19; ihm 208), and should not be confused with consciousness since the former is a distinct faculty that arises later in life (eip op. cit; ihm 15).
5 This example was likely to be of particular personal interest to Reid due to his acquaintance with a Cambridge lecturer in geometry and optics (the ‘Dr Saunderson’ of ihm 95) who was in fact blind (Nichols 2007: 5).
6 Note that even a painting, itself a facsimile of some visible figure, has a visible figure, since we always see it from some particular perspective as a real physical object, even though our minds are inclined to pass over the initial impression — the ‘sign’ — to the objects that are signified, whether this be the painting or whatever it depicts.
7 In the sense of Dummett (1991).
8 Cf. Malebranche (1688).
9 Reid employs a similar argument to determine whether sight would be possible in the absence of the sensation of colour (ihm 100), concluding that visible figure is thereby independent of any form of sensation.
10 Here, the two senses of ‘immediate’ become clearly evident.
11 This is not dissimilar to McDowell’s (2007) reading of Kant, which construes sensation, conception and belief as different aspects of a single, holistic perceptual experience.

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