The particularity and phenomenology of perceptual experience Susanna Schellenberg Published online: 23 March 2010 ! Springer Science+Business Media B.V. 2010 Abstract I argue that any account of perceptual experience should satisfy the following two desiderata. First, it should account for the particularity of perceptual experience, that is, it should account for the mind-independent object of an experience making a difference to individuating the experience. Second, it should explain the possibility that perceptual relations to distinct environments could yield subjectively indistinguishable experiences. Relational views of perceptual experience can easily satisfy the first but not the second desideratum. Representational views can easily satisfy the second but not the first desideratum. I argue that to satisfy both desiderata perceptual experience is best conceived of as fundamentally both relational and representational. I develop a view of perceptual experience that synthesizes the virtues of relationalism and representationalism, by arguing that perceptual content is constituted by potentially gappy de re modes of presentation. Keywords Perceptual experience ! Perceptual content ! Gappy content ! Particularity ! Relations ! Representations There are two radically different conceptions of perceptual experience. According to relationalism, perceptual experience is fundamentally a matter of standing in an awareness or an acquaintance relation to objects. According to representationalism, perceptual experience is fundamentally a matter of representing objects. Relationalism and representationalism are widely considered to be in conflict.1 I aim to show that they are not in conflict with one another and, indeed, that perceptual experience is best thought of as fundamentally both relational and representational. S. Schellenberg (&) Philosophy Program RSSS, Australian National University, Canberra, ACT 0200, Australia e-mail: susanna.schellenberg@anu.edu.au 1 For recent articulations of this view, see Campbell 2002. 123 Philos Stud (2010) 149:19–48 DOI 10.1007/s11098-010-9540-1 I will focus on what I take to be two desiderata for any account of perceptual experience. One desideratum is to account for the particularity of perceptual experience, that is, to account for the mind-independent object of an experience making a difference to individuating the experience. Let us call this the particularity desideratum. The other desideratum is to explain what accounts for the subjective indistinguishability of perceptual experiences of distinct environments. Let us call this the indistinguishability desideratum. As I will argue, relationalism can easily satisfy the particularity desideratum, but not the indistinguishability desideratum. By contrast, representationalism can easily satisfy the indistinguishability desideratum, but not the particularity desideratum. I will offer a synthesis of these approaches that satisfies both desiderata. In §1 and §2, I will discuss these two desiderata by articulating the problems of what I will call austere relationalism and austere representationalism. To a first approximation, austere relationalism is a view according to which perceptual experience lacks any representational component, while austere representationalism is a view according to which perceptual experience lacks any relational component. In §3, I will consider several ways of understanding the thesis that perceptual experience is both relational and representational. In §4, I will argue that the virtues of relationalism and representationalism can be synthesized, if the content of experience is understood in terms of potentially gappy de re modes of presentation. I will defend this thesis by developing what I call the Fregean gappy content view. In §5, I will show how this view makes it possible to satisfy both the particularity and the indistinguishability desiderata. The aim of this project is purely positive and my argument for the Fregean gappy content view is an inference to the best explanation. I will consider many competitor views along the way, however, I will argue against them only to the extent that it helps motivate and situate the view I will develop in a broader philosophical context. First, it is necessary to make a few terminological remarks. When I speak of an experience without further qualification, I mean an experience that is a perception, a hallucination, or an illusion. I will focus on the case of experiencing objects, but analogous arguments can be made for the cases of experiencing properties, events, or scenes. When I speak of objects without further qualifications, I mean material, mind-independent objects, such as cats, cups, or carrots. Finally, when I speak of representationalism without further qualifications, I mean no more than a view according to which perceptual experience necessarily has content insofar as it is fundamentally a matter of representing objects, properties, events, or scenes. This thesis is agnostic on all the possible ways of understanding the relationship between the content and phenomenology of experience. Indeed, it is compatible with thinking that there are aspects of the phenomenology of perceptual experience that are independent of the content of experience. 1 Particularity and austere representationalism There are at least two ways to individuate experiences. On one view, experiences are individuated solely by the phenomenology that the subject experiences. I will 20 S. Schellenberg 123 call this the mental state view of experience. Versions of this view have been defended by Tye (1995), Lycan (1996), Byrne (2001), and Block (2003) among others. On another view, experiences are individuated by the phenomenology and the material, mind-independent objects, properties, scenes, or events to which the subject is perceptually related. I will call this the environment-encompassing view of experience since it conceives of the metaphysical structure of experience as encompassing the environment in which the subject is enjoying a certain phenomenology. Versions of this view have been defended by Campbell (2002), Martin (2002), and Brewer (2006) among others. The motivations for thinking that experience is fundamentally representational typically go hand in hand with the motivations for embracing the mental state view. Similarly, the motivations for thinking that experience is fundamentally relational typically go hand in hand with the motivations for embracing the environment-encompassing view of experience. However, the fault line between relational and representational views does not coincide with the fault line between environment-encompassing and mental state views. Sense-data theory as defended by Price (1950) and Moore (1953) is a mental state view that is not representational. Moreover, Searle (1983) and McDowell (1984) among others defend environment-encompassing representational views. With the distinction between mental state views and environment-encompassing views in hand, the aim of this paper can be articulated more precisely as defending an environment-encompassing representational view that satisfies both the particularity and the indistinguishability desiderata. The view I will defend is fundamentally relational insofar as it is environment-encompassing. In this section, I will argue that experiences are best thought of as individuated not only by their phenomenology, but also by the particular environment in which the subject is experiencing. Why should we be concerned with the particularity of perceptual experience? The main reason for the purposes of this paper is to give a good account of the accuracy conditions of perceptual experience.2 The accuracy conditions of a perceptual experience specify the way the world would have to be for the content of the experience to be accurate. Given this constraint there are several different ways of understanding accuracy conditions. If the content of experience lays down a condition under which it is accurate in a way that is sensitive to which particular object (if any) is perceived, then the way the experiencing subject's environment is will make a difference to the content of her experience. The motivation for this way of understanding accuracy conditions is that the condition that needs to be met for an experience to be accurate is not just that there is an item in the world that possesses the properties specified by the content. It is necessary to specify which particular object in a subject's environment is represented to determine whether the subject's environment really is as it is represented to be. Consider a subject who perceives a coffee cup. For her content to be accurate, she needs to be representing the very coffee cup that she is perceiving. If she experiences cup1, her experience is accurate only if she is perceptually related to cup1. So if the cup is replaced by a 2 In the interest of generality, I will talk of the content of experience as having accuracy conditions rather than truth conditions. Only if the content of experience is understood as having a propositional structure, will it have truth conditions. The particularity and phenomenology of perceptual experience 21 123 numerically distinct but qualitatively indistinguishable coffee cup, then the accuracy conditions of her experiences change-even if she cannot tell the two coffee cups apart. If this is right, then for an experience with the content ''that coffee cup is white'' to be accurate it is not sufficient for ''that'' to refer to some coffee cup instantiating the right properties. It is necessary for ''that'' to refer to the particular object perceived. If the content of experience lays down the conditions under which the experience is accurate and the accuracy of an experience depends on how the environment is, then the particular object to which the subject is perceptually related will make a constitutive difference to the content of the experience. I will argue that the particularity of perceptual experience can only be accounted for, if perceptual content is understood to be at least in part object-dependent. Before I do so, it will be necessary to discuss in more detail what is meant with the particularity of perceptual experience. Consider a subject who sees a white coffee cup (cup1) at t1. Let us assume that she closes her eyes briefly and without her noticing cup1 is replaced with a numerically distinct but qualitatively indistinguishable white coffee cup (cup2). At t2 she is perceptually related to cup2. Even though she cannot tell, her experience before the cup was exchanged is of a different object than her experience after the cup has been exchanged. What is the difference between her experiences at t1 and t2? There are at least four ways of understanding the difference. Correspondingly, there are at least four ways of understanding the particularity of perceptual experience. The experiences can be understood as differing with regard to (1) the causal or (2) the perceptual relations to the object in view, with regard to (3) their phenomenology, or with regard to (4) their content. It is uncontroversial that the two experiences differ insofar as the experiencing subject is causally related to distinct objects. Furthermore-assuming that there is such a thing as a perceptual relation between a subject and a perceived object-it is uncontroversial that the experiences differ insofar as the subject is perceptually related to distinct objects. The critical question is whether these differences in causal or perceptual relations affect the phenomenology or the content of the experiences. Martin (2002) argues that only if perceptual experience is objectinvolving can particularity be accommodated. Chalmers argues that although the phenomenology of perceptual experience presents us with objects directly, it does not reveal ''the intrinsic haecceitistic natures of objects'' (2006a, p. 109). I aim to show that there is something right about both claims, but that different notions of particularity are in play. In order to defend this idea, it will be helpful to introduce the distinction between the relational and the phenomenological particularity of a mental state. To a first approximation, a mental state instantiates relational particularity if and only if the experiencing subject is perceptually related to the particular object perceived.3 A mental state instantiates phenomenological particularity if it (perceptually) seems to the subject as if there is a particular object present. The notion of phenomenological particularity can be specified more strongly in a more general way: a mental state instantiates phenomenological particularity if and only if the particularity is in the scope of how things seem to the subject, such that it seems to the subject that there 3 I will elaborate on different metaphysical implications of this thesis shortly. 22 S. Schellenberg 123 is a particular object or a particular instance of a property present.4 Every perceptual experience of an object exhibits phenomenological particularity. Indeed it is unclear what it would be to have an experience that seems to be of a material, mindindependent object without it seeming to the subject that the object is a particular object. If a subject has an experience that is intentionally directed at a particular object, it will seem to her as if she is experiencing a particular object-regardless of whether there is in fact an object present. If this is right, then any view on which perceptual experience is object-directed is committed to saying that perceptual experience exhibits phenomenological particularity. The notion of relational particularity picks out what is sometimes referred to as the relationality of perceptual experience (e.g. Crane 2006). In contrast, the notion of phenomenological particularity picks out what is sometimes referred to as the intentional directedness (e.g. Horgan and Tienson 2002) or as the direct presentational phenomenology of an experience (e.g. Chalmers 2006a). Often the relationality and intentional directedness of perceptual experience are implicitly equated. This is problematic. One should allow for the possibility that a subject can be intentionally directed at what seems to her to be a material, mind-independent object even if there is no such object present, while acknowledging that there is a difference in relational particularity between experiences of numerically distinct but qualitatively indistinguishable objects. As I will show, only if we recognize the distinction between phenomenological and relational particularity can we account for the difference between perceptions of distinct but qualitatively indistinguishable objects. The claim that perceptual experience instantiates relational particularity can be interpreted in at least three ways. On the causal version, the idea is simply that when a subject sees an object, she is causally related to the object she sees. It is uncontroversial and compatible with almost any view of perceptual experience that there is such a causal relation between subject and object when a subject sees the object-though views differ dramatically with regard to how much explanatory weight the causal relation can carry. Consider the case of two experiences, one of which is a perception, the other of which is a subjectively indistinguishable hallucination. Most representationalists will accept that the two experiences differ in at least one respect, namely insofar as the content of the perception is satisfied by an object, while the content of the hallucination is not so satisfied. Accepting the causal 4 Siegel (2006) distinguishes between simple and complex phenomenology. Phenomenology is simple if it reveals only the objects and properties that the subject is aware of. Phenomenology is complex if it reveals also to the subject that she is perceptually (or causally) related to these objects and properties. Searle (1983) and Siegel (2006) argue that the phenomenology of experience is complex. Chalmers (2006a, p. 76) argues that although introspection may exhibit complex phenomenology, perceptual experience itself exhibits only simple phenomenology (at least in the case of perception of colors). My argument is neutral on whether phenomenology is simple or complex. For the sake of definiteness, I will use ''phenomenological particularity'' in a way that is committed to simple phenomenology. If phenomenology is complex, then the specification of phenomenological particularity must be reformulated as follows: a mental state instantiates phenomenological particularity if and only if it seems to the subject that she is perceptually (or causally) related to a particular object or a particular instance of a property. As on the simple view, the particularity is in the scope of how things seem to the subject. The particularity and phenomenology of perceptual experience 23 123 version is compatible with the content and phenomenology of the two experiences being the very same irrespective of which particular object (if any) the subject is causally related to. So the subject could be in the very same mental state regardless of her environment. As a consequence, the particularity of perceptual experience cannot be accounted for in a way that will make a constitutive difference to the accuracy conditions of perceptual experience. For this reason, I will reject the causal version as an understanding of relational particularity that will serve our purposes. In order to satisfy the particularity desideratum, we need a notion of relational particularity that accounts for the metaphysical thesis that the object of perception is a constituent of the perception. The following two versions of relational particularity account for this metaphysical thesis. On the phenomenological version, the idea that objects are constituents of perceptions implies that the particular object perceived makes a constitutive difference to the phenomenology of the experience. One rendering of this version is defended by Martin (2000) under the label ''Actualism''. It is consistent with this version that there is a causal relation between subject and object when a subject sees an object, however this version incorporates far more than such a causal relation. As I will argue in §2, the phenomenological version has the counterintuitive consequence that a perception and a hallucination are necessarily phenomenally distinct. Moreover, it has the counterintuitive consequence that perceptions of numerically distinct but qualitatively indistinguishable objects are phenomenally distinct-unless phenomenology is taken to be multiply realizable. As I will show, if phenomenology is taken to be multiply realizable in the full sense, then the phenomenological version cannot account for relational particularity. On the content version, the idea that objects are constituents of perceptions consists of two claims: (1) A subject has an accurate perceptual experience only if she is perceptually related to the object she is experiencing. (2) The particular object to which the subject is related makes a constitutive difference to the accuracy conditions and thus to the content of the experience. As I will show, the content version avoids the counterintuitive consequences of the phenomenological version. Maintaining the content version will prove crucial to synthesizing relationalism and representationalism. In light of these clarifications of the notion of particularity, we can discuss to what extent a representationalist can account for particularity. Consider a view on which experience lacks any relational component, that is, an austere representationalist view. The essential idea of such a view is that to have an experience is to represent an object with the ensuing content being phenomenal content. For our purposes it will suffice to think of phenomenal content as content that corresponds to how things seem to an experiencing subject or what it is like for her to be experiencing. If a perception can have the same phenomenal content as a hallucination, phenomenal content must be independent of whether the subject is related to a material, mind-independent object. So if experiential content is phenomenal content, then there can be an exact duplicate of an experience and its content in an environment in which a different object is present or an environment 24 S. Schellenberg 123 in which no relevant object is present. Stated more precisely, austere representationalism is committed to the following three theses: (1) Experiences have content. (2) A perception and a hallucination can have the same phenomenology. (3) The content of experience is either identical with phenomenology or supervenes on the phenomenology of the experience.5 I will argue that it follows from these three theses that (4) the particular material object to which a subject is perceptually related cannot make a constitutive difference to the content of her experience. I will embrace the first two theses of austere representationalism, but will reject the third thesis. By rejecting the third thesis, the commitment to the fourth thesis can be avoided. The contrast between austere representationalism and relationalism is orthogonal to the contrast between views according to which content supervenes on phenomenology and views according to which phenomenology supervenes on content. Any view according to which the phenomenology of experience is identified with the representational content of that experience is a species of austere representationalism. So-called strong representationalism is thus a species of austere representationalism. The scope of austere representationalism is, however, broader than that of strong representationalism. Austere representationalism is compatible with there being aspects of phenomenology that do not supervene on the content of the relevant experience. So there is room in austere representationalism for phenomenological differences due to perceptual modes and non-representational sensations. One way of understanding the content of perceptual or hallucinatory experiences under the constraint of the austere representationalist thesis is that it is existentially quantified content of the form that there is an object x that has a certain property P: ap;h ! " "9x#Px Most experiences will attribute a multitude of properties to any given object. Arguably, any visual experience as of an object attributes at least a spatial property and a color property along with their correlating situation-dependent properties to the object.6 I will work with the simplifying assumption that there can be an experience of an object that has only one property. However, my argument generalizes to the more realistic case involving a multitude of properties. The thesis that experiential content is existentially quantified content posits that experience represents only that there is an object with the relevant properties in the external world. No element of the content depends on whether there is in fact such an object present. So it is possible to be in a mental state with the relevant content 5 McGinn (1982), Davies (1992), Tye (1995), Lycan (1996), Byrne (2001), and Pautz (2009) among others have defended views that are committed to these three theses. 6 For a defense of situation-dependent properties, see my 2008. The particularity and phenomenology of perceptual experience 25 123 regardless of whether there is a particular object present and regardless of what object is present. The object of the experience does not fall out of the picture altogether on the austere representationalist view. Although no reference to the object is necessary to specify the content, the austere representationalist can say that a subject perceives an object o at a particular location only if o satisfies the existential content of the subject's experience. So the content of the experience is accurate only if there is an object at the relevant location that possesses the properties specified by the content. However the important point is that whether an object of the right kind is present has a bearing only on the accuracy of the content. Whether an object of the right kind is present has no repercussions for the content itself. The main advantage of austere representationalism is that it easily and elegantly explains how a perception and a hallucination can be subjectively indistinguishable. Indeed accounting for this possibility is one of the main motivations for thinking of experiential content in terms of phenomenal content. As Davies puts it: ''the perceptual content of experience is a phenomenal notion: perceptual content is a matter of how the world seems to the experiencer ... If perceptual content is, in this sense, 'phenomenological content' ... then, where there is no phenomenological difference for a subject, then there is no difference in content'' (1992, p. 26). By equating perceptual content with phenomenal content, austere representationalism can easily account for the phenomenological particularity of both perceptions and hallucinations. The main problem with austere representationalism is that it does not account for relational particularity. The view cannot account for the difference between a subject's perception of cup1 at t1 and her perception of the qualitatively indistinguishable cup2 at t2 on either the content or phenomenological versions of relational particularity. Davies explicitly embraces this view: ''if two objects are genuinely indistinguishable for a subject, then a perceptual experience of one has the same content as a perceptual experience of the other'' (1992, p. 26).7 According to austere representationalism, same phenomenology entails same content (from 3 above). So, two subjectively indistinguishable experiences cannot differ in content-irrespective of what object, if any, the subject is related to. As a consequence, the difference in the accuracy conditions of the two experiences cannot be reflected in the contents of the experiences. It follows that austere 7 McGinn (1982) and Millar (1991) argue for a similar thesis. This view is subject to well-known counterexamples, which I will not rehearse here. They have been discussed in detail by Soteriou (2000) and Tye (2007) by expanding on Grice's (1961) discussion of so-called ''veridical hallucinations''. Searle (1983) aims to account for particularity within the framework of existentially quantified contents by building causal conditions into the existential contents. In short, the idea is that a descriptive condition picks out an object as the cause of the experience. By doing so, Searle builds the causal relation to particular objects into the phenomenology of the experience. Thereby, he combines the phenomenological and content versions of the metaphysical thesis that the object is a constituent of the experience. However, this solution arguably does not solve the problem and is at odds with the phenomenology of experience. As I will discuss in §2, arguing that the particular object to which the subject is causally related is reflected in the phenomenology has the counterintuitive consequence that perceptual experiences of numerically distinct but qualitatively indistinguishable objects differ with regard to their phenomenology. 26 S. Schellenberg 123 representationalism cannot account for relational particularity and thus cannot satisfy the particularity desideratum. Therefore, if perceptual content should reflect relational particularity, as I have argued, then perceptual content cannot be equated with phenomenal content. Against austere representationalists, I will argue that relational particularity can only be accommodated if part of perceptual content is object-dependent. However with representationalists and against austere relationalists, I will argue that only phenomenological particularity is reflected in the phenomenology of experience. Yet first, I will consider the view that perceptual experience is fundamentally a matter of standing in an awareness or an acquaintance relation to objects. 2 Subjective indistinguishability and austere relationalism It used to be common ground that perceptual experience represents the world as being one way rather than another. This idea has been questioned by sense-data theorists and most recently by what I will call austere relationalists: Campbell (2002), Martin (2002), Travis (2004), and Brewer (2006) among others.8 There are four main reasons for austere relationalists to question the representational character of perceptual experience. A first objection is based on the observation that perception is not the kind of thing that can be accurate or inaccurate. Perception is simply a relation between a perceiving subject and an object, a property-instance, a scene, an event, or alternatively an event in which such a relation obtains. If accounting for accuracy conditions is the reason for introducing perceptual content, then denying that experience has accuracy conditions undermines at least this reason for positing that experience has content. A second objection is that only if perceptual experience is itself non-representational can it constitute the evidential basis for demonstrative thought. A third objection is that representational views misconstrue the phenomenological basis of perceptual experience insofar as they detach the phenomenology of experience from relations to qualitative features of the world. A fourth objection is that if perception has representational content, then the way an object looks on a given occasion must fix what representational content the perception has. However, the way an object looks on a given occasion does not fix what representational content the perception has. Therefore, perception does not have representational content.9 8 Campbell (2002) calls his view the ''relational view'', Martin (2002) calls his ''naıve realism'', while Brewer (2007) calls his the ''object view''. I will refer to the view as ''austere relationalism'' since the most distinctive features of the view are arguably the central role of relations between perceiving subjects and the world as well as its austerity: the view is austere insofar as it denies that experience has any substantive representational component. 9 This summary does not do justice to the subtleties of austere relationalism. For a detailed discussion of the view, see my forthcoming-a. Naturally, different austere relationalists emphasize different ones of these four objections. Brewer emphasizes the first objection, Campbell emphasizes the second and third objection, Martin emphasizes the third objection, and Travis emphasizes the fourth objection. The particularity and phenomenology of perceptual experience 27 123 These four lines of criticism have given rise to a view according to which perceptual experience is essentially a matter of a subject s standing in an awareness or an acquaintance relation R to a mind-independent object o10: bp ! " Rso As Brewer formulates the idea: The course of perceptual experience ... provide[s] the subject with the grounds for her actual beliefs about the world, and also for the various other beliefs which she might equally have acquired had she noticed different things, or had her attention instead been guided by some other project or purpose. It does so, though, not by serving up any fully formed content, somehow, both in advance of, but also in light of, these attentional considerations, but, rather, by presenting her directly with the actual constituents of the physical world themselves. (2006, p. 178) Austere relationalism is a radical version of disjunctivism, that is in short, a view according to which perceptions and hallucinations share no common element.11 Most disjunctivists have argued that while hallucinations are not representational, perceptions do represent objects.12 Austere relationalism is a radical version of disjunctivism insofar as it denies not only that hallucinations are representational; it denies also that perceptions are representational. Moreover, austere relationalism renders the form of perception in a way that a hallucination could not possibly fit. Austere relationalism is structurally similar to sense-data theory and is motivated in part by its insights. So it will help to contrast the two views. While austere relationalists argue that the object to which a subject is perceptually related is a material, mind-independent object, sense-data theorists argue that the object in question is a sense-datum. This difference has many repercussions. The most important for our purposes is that sense-data theorists take the structure of a perception to be the very same as that of a hallucination. In both cases a subject's experience consists in being related to sense-data. Since hallucinations and perceptions have the very same structure, sense-data theory can easily satisfy the indistinguishability desideratum. However, sense-data theory has it that a subject can have the very same experience with the very same sense-data regardless of whether or not the subject is perceptually related to a mind-independent object. So according to sense-data theory, subjectively indistinguishable experiences will be the very same with respect to their phenomenology (and content-if experience is understood to have content) regardless of the experiencing subject's environment. Therefore, sense-data theory cannot account for relational particularity. 10 The view could also be formulated as a matter of a subject standing in an awareness relation to a property-instance, a scene, an event, or alternatively an event in which such a relation obtains. As stated earlier, I will focus on the case of perceiving objects. 11 The metaphysical thesis that perception and hallucination share no common element was first articulated by McDowell (1982). 12 See for instance Hinton 1973, Snowdon 1981, and McDowell 1982. 28 S. Schellenberg 123 By contrast to sense-data theorists, austere relationalists conceive of the structure of perception in a way that a hallucination could not possibly have. Since a hallucinating subject is not perceptually related to the material object she seems to be seeing, a hallucination cannot be modeled on the Rso-form of perception. This way of thinking about perceptual experience has many virtues. The most salient for the present discussion is that it can easily account for relational particularity. Insofar as the subject is perceptually related to this rather than that cup, she perceives this rather than that cup. The perceptual relation between the subject and object secures relational particularity. However, austere relationalism comes at a price. The critical problem is that it cannot easily account for how a perception and a hallucination could be subjectively indistinguishable. There are many ways of understanding the claim that two experiences are subjectively indistinguishable. Williamson (1990) uses the expression to pick out an epistemic notion. In short, the idea is that two experiences e1 and e2 are subjectively indistinguishable for a subject if and only if she is not able to know by introspection alone that e1 and e2 are not the same. I will follow this use. I will not argue here for the thesis that perceptual experiences of distinct environments could be subjectively indistinguishable, nor will I argue for the thesis that this possibility needs explaining.13 In the context of this paper, I will take both for granted. Indeed, I will posit that any view of experience should explain what accounts for the subjective indistinguishability of perceptual experiences of distinct environments. This is what we have called the indistinguishability desideratum. Most austere relationalists stipulate that experiences in distinct environments can be subjectively indistinguishable, but little if anything is given by way of explanation of what accounts for the subjective indistinguishability of the experiences. According to austere relationalism, one cannot understand the phenomenology of experience independently of its subject matter. If the subject matter consists (at least in part) of the perceived mind-independent objects, then this claim amounts to the thesis that the phenomenology of experience is constituted (at least in part) by these objects. Campbell (2002, p. 127) and Martin (2002, p. 184 ff.) explicitly embrace this thesis. Campbell argues that the object of perception is a constituent of the experience insofar as attending to the object brings about an unrepeatable phenomenal aspect of the experience. If phenomenology is not multiply realizable and if the phenomenology of experience is constituted by material objects, then it follows that the phenomenology of experiences of numerically distinct objects necessarily differs, even if the objects are qualitatively indistinguishable. Campbell commits himself to this radical austere relationalist thesis in his discussion of the following inference: P1: That woman is running. P2: That woman is jumping. Conclusion: That woman is running and jumping. As he argues, ''[r]ecognizing the validity of the inference requires that your experience should make the sameness of the object phenomenally accessible to 13 For discussion, see my forthcoming-b. The particularity and phenomenology of perceptual experience 29 123 you'' (2002, p. 129f.). If the woman who is running were in fact the identical twin of the woman who is jumping, then Campbell would have to say that one's experience makes the difference of the objects phenomenally accessible to one, should one recognize the invalidity of the inference. It is however counterintuitive that the distinctness of the objects would be phenomenally accessible to one through perceptual experience-at least if the two women were indistinguishable to the perceiver and if she did not notice that there were two different women present. Austere relationalists could avoid this counterintuitive consequence by arguing that phenomenology is multiply realizable. The idea is that the very same phenomenology could be realized by relations to numerically distinct but qualitatively indistinguishable objects. If phenomenology is multiply realizable, then a subject who is perceptually related to cup1 could have instantiated the very same phenomenology had she been perceptually related to cup2. By accepting multiple realizability of phenomenology, austere relationalists could allow that the perception of cup1 is subjectively indistinguishable from the perception of cup2 in the full sense and, thus, meet the indistinguishability desideratum. Martin accepts a version of this idea. He argues that perceptions of numerically distinct but qualitatively indistinguishable objects have the same phenomenal character. Nonetheless, he denies that they have the same phenomenology in the full sense. By introducing a different kind of phenomenology, which he calls ''phenomenal nature'', he argues that there is a phenomenal difference between the two experiences despite the sameness in phenomenal character: Once we reflect on the way in which an experience has a subject matter ... then we need a way of making room for the essentially or inherently particular aspects of this as well as the general attributes of experience. We need to contrast the unrepeatable aspect of its phenomenology, what we might call its phenomenal nature, with that it has in common with qualitatively the same experiential events, what we might call its phenomenal character. (2002, p. 194) The notion of a phenomenal nature captures an unrepeatable aspect of the phenomenology of an experience that, according to Martin, cannot be specified without reference to the actual object of the experience.14 Positing such objectdependent and unrepeatable phenomenal natures entails that any two experiences of distinct objects necessarily differ phenomenally; even if the relevant objects are qualitatively indistinguishable. This consequence is counterintuitive as a thesis about phenomenology. It is counterintuitive even if one acknowledges that two experiences can exhibit a phenomenal difference while being subjectively indistinguishable. Granted it is plausible that two experiences could be 14 Assuming that there is such an unrepeatable aspect of phenomenology, it is not obvious why it must be due to the particular object, rather than the particular event in which the particular object is perceived. On a sufficiently holistic view of experience, every experience may be understood as necessarily phenomenally distinct insofar as it is a distinct and unique event of experiencing. On such a holistic view of experience, one could say that the phenomenology of every experience is distinct regardless of the relation to objects. So one could hold that an aspect of phenomenology is unrepeatable while rejecting the thesis that phenomenology instantiates relational particularity. 30 S. Schellenberg 123 subjectively indistinguishable despite phenomenal differences between the experiences due to minute differences in the perceived colors or shapes. Such differences are, however, at least in principle subjectively accessible since there is a qualitative difference between the perceived colors or shapes. We would detect the differences, were our sensory apparatus better. The case of numerically distinct but qualitatively indistinguishable objects is different, since in this case there is no qualitative difference between the perceived objects. We could not detect a difference, even if our sensory apparatus were perfect. So accepting the possibility of such differences in phenomenology that are not subjectively accessible requires accepting that there can be aspects of phenomenology that are in principle not subjectively accessible to the experiencing subject. Consider an austere relationalist who accepts that phenomenology is multiply realizable without endorsing Martin's thesis that the particular object perceived makes a difference to phenomenology. Such an austere relationalist has it that perceptions of numerically distinct but qualitatively indistinguishable objects have the very same phenomenology. While such an austere relationalist could satisfy the indistinguishability desideratum and could avoid the counterintuitive consequences discussed above, he could not satisfy the particularity desideratum. This brings out a dilemma for the austere relationalist. If he holds that two experiences of numerically distinct but qualitatively indistinguishable objects do not differ phenomenally, then he cannot appeal to the phenomenology of perceptual experience to account for relational particularity. If however he appeals to phenomenology to account for relational particularity, then he must embrace the counterintuitive consequence that perceptual experiences of numerically distinct but qualitatively indistinguishable experiences differ phenomenally and must accept that there can be aspects of phenomenology that are in principle not subjectively accessible. The obvious solution to the problem is to argue that it is not the phenomenology, but rather the content of perceptual experience that accounts for relational particularity. Since the austere relationalist holds that perceptual experience does not have content, this solution is not open to him. In the rest of this paper, I will present a way of accounting for relational particularity while respecting the intuition that experiences of qualitatively indistinguishable objects do not differ phenomenally. I will argue that although experiences of distinct objects necessarily differ with regard to their content, this difference is not revealed in phenomenology. 3 The relational and representational character of perceptual experience The austere versions of relationalism and representationalism are not the only options. In the rest of this paper, I will argue that perceptual experience is fundamentally both relational and representational. By doing so, I will present a way of satisfying both the particularity and the indistinguishability desiderata. I will argue that perceptual experience has both a component that grounds phenomenology and a component that accounts for relational particularity without affecting The particularity and phenomenology of perceptual experience 31 123 phenomenology. Perceptual experience plays multiple explanatory roles and, I will argue, its content should be understood as serving multiple explanatory purposes. The most minimal representationalist commitment is that there is a distinction between the possibilities in which things are as they are represented to be and the possibilities in which things are otherwise. The content is accurate if things are as represented. When I speak of perceptual experience as being representational without qualification I mean no more than this idea. There are many different ways of understanding experiential content given this constraint. The content can be conceived of as a proposition, a map of the environment, an image-like representation, or any number of things. If my argument holds at all, it does not depend on which of these ways experiential content is conceived. How must we understand experience so that we can satisfy both the particularity and the indistinguishability desiderata? There are many possible ways of understanding the idea that perceptual experience is both relational and representational. A natural suggestion given how we have set up the dialectic is to combine austere relationalism with austere representationalism, thereby construing the form of perceptual experience as a conjunction of two elements: cp ! " Hs\"9x#Px[ and Rso Subject s stands in a representation relation H to the existentially quantified content that there is an object x that has the property P and s stands in an awareness or acquaintance relation R to an object o. The form of a hallucination will be: ch" # Hs\"9x#Px[ Let us call this view conjunctivism. On this suggestion, two elements are in place in a successful perceptual experience. Neither element is dependent on the other. A hallucinating subject stands only in relation to the proposition that there is an object that has a certain property. Since the subject does not stand in a perceptual relation to an object, the representation is only of a seeming object. Conjunctivism is a representational view that individuates perceptual experiences not just by the relevant mental states, but also by the relation between the experiencing subject and the environment. The problem with conjunctivism is that all aspects of the representational element are independent of whether the object is present. As a consequence, relational particularity cannot be accounted for. Although conjunctivism builds perceptual relations between subjects and objects into the form of perceptual experience, this relational element has no affect on either its content or its phenomenology. In this respect, the suggestion just is a version of austere representationalism that makes explicit the causal relation between subject and object in the case of an accurate perceptual experience. Indeed, most austere representationalists will acknowledge that these two elements are in place in the case of an accurate perceptual experience. An alternative traditional way of synthesizing relationalism and representationalism is to endorse content disjunctivism. On such a view, perceptual content is radically object-dependent insofar as an experiencing subject only represents if she 32 S. Schellenberg 123 is perceptually related to an appropriate object in her environment. Since perceptual content is radically object-dependent, a hallucinating subject does not represent. It only seems to her as if she is representing something. So there is only an illusion of content.15 While such a view has a certain appeal if one is concerned with the epistemology of perceptual experience, it is less attractive if one is concerned with the phenomenology of perceptual experience. For the present purposes, the main problem with content disjunctivism is that it is unclear on such a view what explains the phenomenology of hallucinations. As a consequence, it is unclear how content disjunctivism could satisfy the indistinguishability desideratum. Most content disjunctivists posit that a hallucination could be subjectively indistinguishable from a perception, but little if anything is given by way of explanation of this phenomenon. So while content disjunctivism synthesizes relational and representational approaches, it does not do so in a way that explains how a hallucination and perception could be subjectively indistinguishable. There is much more to be said about this problem and the possible ways that a content disjunctivist could avoid it. I cannot here do justice to the subtleties of the view.16 Rather than further pursue a discussion of content disjunctivism, I will focus on developing a view that avoids this problem. The problem is avoided if the content of experience is understood to be only partly object-dependent. More specifically, the idea is that the content of a hallucination involves a gap that in the case of a perception is filled by an object. In the case of a hallucination, the gap is not so filled. The gap marks that something is missing. The content expresses which properties the object of the experience has or would have, were an object present. Traditionally, gappy contents are thought of in terms of Russellian propositions.17 On such a view, the content is gappy because an object is missing. The content expresses that the object that is (or seems to be) present instantiates property P. The content of a hallucinatory experience will be an ordered pair of a gap and a property: dh" # \ ; P[ In the case of an accurate perceptual experience, the gap is filled by an object o: dp ! " \o; P[ So the content of experience determines a schema for the condition of satisfaction of any particular experience with that content. The content schema includes a slot which in the case of a perception is filled by whichever object is in the relevant causal relation to the experiencing subject. The main problem with this suggestion is that in order to account for hallucinations of uninstantiated properties, such as supersaturated red or Hume's missing shade of blue, a proponent of such a view must conceive of the content of 15 Versions of this view have been defended by Hinton (1973), Snowdon (1981), and McDowell (1982). 16 For a detailed recent discussion, see Haddock and Macpherson 2008. 17 See Braun 1993. Such a Russellian way of thinking about gappy contents has been defended also by Bach (2007) and Tye (2007). For a Fregean gappy content view, see my 2006. This paper develops ideas from that project. The particularity and phenomenology of perceptual experience 33 123 hallucination as constituted potentially by uninstantiated properties. By doing so, she commits herself not just to a controversial metaphysical view of properties but also to a controversial phenomenological view of experience. The view is metaphysically controversial since accepting the existence of uninstantiated properties requires some kind of Platonic ''two realms''-view on which there is more to reality than the concrete physical world. The view is phenomenologically controversial since it is not clear what it would be to be sensorily aware of an uninstantiated property.18 There are several possible ways for the Russellian to respond to the phenomenological problem. She might distinguish between being sensorily and cognitively aware of something. This would allow her to accept that we cannot be sensorily aware of uninstantiated properties, but argue that hallucinating subjects are cognitively aware of uninstantiated properties. However, now the problem arises how perceptual and hallucinatory experiences could be subjectively indistinguishable. Presumably being cognitively aware of something is phenomenally distinct from being sensorily aware of something. If this is right, then it is unclear how the Russellian gappy content view could satisfy the indistinguishability desideratum.19 The Russellian could circumvent this second phenomenological problem in at least two ways. One option is to argue that subjects are sensorily aware of uninstantiated properties regardless of whether they are perceiving or hallucinating. A second option is to argue that subjects are cognitively aware of uninstantiated properties regardless of whether they are perceiving or hallucinating. Both options face phenomenological problems. The first option leads back to the problem of how one can be sensorily aware of an uninstantiated property. The second option faces the worry of how such a view can account for the particular sensory character of experiences. There are several options for the Russellian to proceed from this point. However, any option will require accepting some kind of Platonic ''two realms''-view and will require accepting that hallucinating subjects are at least potentially either cognitively or sensorily aware of uninstantiated properties. These problems are avoided, if the content of experience is understood as constituted by Fregean modes of presentation of objects and property-instances rather than the naked objects and properties themselves. In the rest of this paper, I will develop a Fregean account of gappy contents and will defend it against possible objections. 4 Fregean gappy content To a first approximation, a mode of presentation can be characterized as the specific way in which a subject conceives of an object or a property when she refers to it. Applied to the case of perceptual experience, the idea is that a mode of presentation is 18 For a classical elaboration of this worry, see Williams 1953. 19 For a detailed discussion of the problems of sensory or cognitive awareness relations to (uninstantiated) properties and more generally the controversial metaphysical and phenomenological commitments of Russellianism about perceptual content, see my forthcoming-b. 34 S. Schellenberg 123 the specific way in which an object or property is perceived by a subject. The fundamental point of modes of presentation is to capture a fineness of grain in contents that references to objects and properties alone could not achieve. On a Russellian understanding, alternative possible modes of presentation can be expressed only insofar as one may have different cognitive attitudes to the same content. The way in which one perceives or thinks of the object is not expressed in the content proper. The problems of Russellianism can be avoided by rendering the content of a hallucination in the following way: eh" #\MOP1" #;MOP2" #[ where MOP1(__) in the object-place specifies the kind of object that has to be present for the experience to be accurate and MOP2(__) in the property-place specifies the properties that this object would instantiate, if the experience were accurate.20 An example will help clarify the idea. Consider again the case of a subject who has a hallucination as of a white coffee cup. The content of her experience specifies both the particular kind of object that would have to be present for the experience to be accurate and the properties that this object would have to instantiate. The content is indeterminate insofar as it does not specify a particular object. The content would be accurate if the subject were related to a particular white cup that instantiates the relevant properties. It is important that the content would be accurate regardless of whether the subject is perceptually related to this or that particular qualitatively indistinguishable white cup. This is just to say that the content does not reflect relational particularity. However, the content does account for the phenomenological particularity of the experience: it accounts for the fact that one has an experience as of a particular object that seemingly instantiates properties. The content of an accurate perceptual experience will be ep ! " \MOP o" #;MOP P" #[ where MOP(o) specifies a particular mode of presentation of an object and MOP(P) specifies a particular mode of presentation of a property P. For any given object, there are many possible modes of presentation. For the content specified byMOP(o) to be determinate, it is important that it is conceived of as one particular mode of presentation of the relevant object. Similarly for the content specified byMOP(P) to be determinate, it is important that it is conceived of as one particular mode of presentation of the relevant property. In contrast to the Russellian view, this view does not posit that the object-place is gappy in the case of a hallucination. It is rather the mode of presentation in the object-place that is gappy. The gappy mode of presentation accounts for the 20 Depending on how one understands the nature of properties that subjects experience, one might argue alternatively that the content of hallucination is eh" #0\MOP" #;MOP P" #[ For the purposes of this paper, we can remain neutral on these two options. As I argue in my forthcoming-b, (eh) is plausible on the assumption that perceiving subjects are related to property-instances, while hallucinating subjects are not related to property-instances since they are not related to the relevant object that could be instantiating the properties. The particularity and phenomenology of perceptual experience 35 123 intentional directedness of the experience to a (seeming) particular object. So it accounts for phenomenological particularity. The gap marks that there is a reference failure and, thus, marks that there is no relational particularity. Now, how should the modes of presentation in play be understood and how should one think of gappy modes of presentation? Traditionally, there are two ways of understanding Fregean modes of presentation that correspond to Frege's use of modes of presentation as accounting for both the cognitive significance of an expression and for a way of referring to an object. On the first understanding, a mode of presentation lays down a condition that something must satisfy to be the object determined by the content. Following common use, we can call these de dicto modes of presentation. Chalmers among others understands Fregean senses in this way: ''Fregean content is supposed to be a sort of phenomenal content, such that, necessarily, an experience with the same phenomenology has the same Fregean content'' (2006a, p. 99). A de dicto mode of presentation constitutes a way of thinking about objects irrespective of whether there is an object present. The relation between content and object is the semantic relation of satisfaction. The condition to be satisfied does not depend on the object that satisfies it, since the mode of presentation simply lays down a condition that something must satisfy to be the object determined by the content. One could argue that the content of experience is constituted by de dicto modes of presentation. On this view, the content of a perception and a subjectively indistinguishable hallucination will both be fp;h ! " \MOPod;MOP p d [ where MOPd o is a de dicto mode of presentation of an object and MOPd p is a de dicto mode of presentation of a property. This way of thinking about content is a version of austere representationalism. Insofar as a de dicto mode of presentation could be the very same regardless of what object, if any, the subject is perceptually related to, the content is independent of the object. If the content does not change as a consequence of the experiencing subject being related to different objects (or to no object at all), then the content will not reflect relational particularity. Therefore, this way of thinking about modes of presentation will not serve our purposes. What we need is a way of thinking about content such that content grounds relational particularity in the case of accurate perceptions and grounds phenomenological particularity in both perceptions and hallucinations. In order to account for phenomenological and relational particularity, it is helpful to contrast de dicto modes of presentation with a second way of understanding Fregean senses, namely de re modes of presentation. There are many possible ways of understanding de re modes of presentation. It has been argued that they are radically object-dependent such that a mental state does not have content properly speaking if the subject is not related to the relevant mind-independent object (e.g. Evans 1982, McDowell 1984). This view is a version of content disjunctivism and thus faces the problems that we discussed in the last section (§3). The most salient problem for the present purposes is that insofar as content disjunctivism has it that hallucinations do not represent, it is unclear on such 36 S. Schellenberg 123 a view what explains the possible subjective indistinguishability of a perception and a hallucination. In contrast to such a view, I will argue that de re modes of presentation are not radically object-dependent, but only partly object-dependent. As I will show, a mental state can have content that is constituted by a de re mode of presentation without the relevant object being present.21 I will argue that the content of experience is constituted by object-related de re modes of presentation, or objectrelated contents for short. A mode of presentation is object-related if and only if the following three conditions hold: (1) The content of any two subjectively indistinguishable perceptions e1 and e $ 1 in which a subject s is perceptually related to the same object o1 in the same way will include MOPr(o1), where MOPr(o1) is the output of a concept that takes objects as inputs. (2) A perception e2 that is subjectively indistinguishable from e1, but of a numerically distinct object o2 will be constituted by the same concept. However, since the input in e2 is a different object than in e1, the ensuing content MOPr(o2) of e2 is different even if o1 and o2 are qualitatively indistinguishable. So object-related de re modes of presentation are injective: if o1 = o2, then MOPr(o1) = MOPr(o2). (3) A hallucination that is subjectively indistinguishable from e1 is constituted by the same concept, but since there is no object present the concept remains empty. The content is MOPr(__). Let us call the view articulated with (1–3) the Fregean gappy content view.22 In the rest of the paper, I will articulate the details of this view and defend it against possible objections. Modes of presentation of property-instances can be specified in an analogous way to modes of presentation of objects. On the suggested view, the content of an accurate perception of a white cup o1 will be 21 Peacocke (1981), Bach (1987/1994), and Recanati (1993) develop different ways of understanding de re modes of presentation that are not fully object-dependent. The understanding of perceptual content developed here builds on their work as well as the work of so-called latitudinarians, according to which de re attitudes (or contents) are a special case of de dicto attitudes (or contents); see in particular Sosa 1970, 1995 and Jeshion 2002. 22 For an earlier version of this view, see my 2006. Strictly speaking the view should be called the Fregean potentially gappy content view or the Fregean potentially gappy object-related de re mode of presentation view. However for reasons of elegance, I will use the shorter label. Burge has been read as defending a gappy content view. However, as Burge writes of his view ''I have heard interpretations ... according to which there is a 'hole' in the representational aspects of the proposition, where the hole corresponds to the object (which completes the proposition). I regard these interpretations as rather silly'' (1977/2007, p. 75). Burge argues that there are demonstrative elements in the content of experience that are in place regardless of whether they refer to the object of experience. As he puts it ''I do not think that a physical re in the empirical world ... is itself 'part of' the belief. ... In my view, the Intentional side of a belief is its only side. In many cases, in my view, a belief that is in fact de re might not have been successfully referential (could have failed to be de re) and still would have remained the same belief. Moreover, the belief itself can always be individuated, or completely characterized, in terms of the Intentional content'' (1991, p. 209). The way I am using the terms, what Burge refers to as de re would be more aptly labeled de dicto. More importantly, insofar as on Burge's view the intentional content of two experiences can be the very same regardless of the environment, the content does not reflect relational particularity. The particularity and phenomenology of perceptual experience 37 123 "gp1#\MOPr o1" #;MOPr P" #[ where MOPr(o1) is an object-related de re mode of presentation of the cup o1 and MOPr(P) is a mode of presentation of the property that this object instantiates. A perceptual experience of a qualitatively indistinguishable but numerically distinct cup o2 will have the distinct content "gp2#\MOPr o2" #;MOPr P" #[ Given injectivity, MOPr(o1) = MOPr(o2). So object-related contents differ depending on what object (if any) the subject is related to. The token content covaries with the environment in which the subject experiences. In the case of a successful perceptual experience, the token content determines a referent. Insofar as the token relational content is individuated in part by the object that it determines, it is at least in part object-dependent. The content of a hallucination will be gh" #\MOP1r " #;MOP 2 r " #[ where MOPr 1(__) in the object-place is an empty object-concept and MOPr 2(__) in the property place is an empty property-concept.23 On the suggested view, the content of experience is constituted by concepts that refer to objects and property-instances. On the notion of concepts in play, concepts cannot be analyzed independently of analyzing what it means to possess a concept.24 For the present purposes, it will suffice to characterize what it means to possess a concept as having the ability to refer to the external, mind-independent objects or property-instances that the concept is of. This ability involves among other things being able to discriminate between the things that fall under the concept and those that do not. So a subject who possesses the concept of redness has the ability to refer to red things, which involves discriminating red things from things that are not red.25 23 As noted above, the content of hallucination could alternatively be understood as having the following content: gh" # 0\MOPr" #;MOPr P" #[ 24 For a developed view of concepts as analyzed in terms of their possession conditions that in turn are analyzed in terms of grounding abilities, see Peacocke 1992 and Sosa 1993. To avoid terminological confusion, any such notion of concepts must be distinguished from any notion on which concepts are mental representations (e.g. Fodor 1975, 1998; Jackendoff 1987; Laurence and Margolis 1999; Carruthers 2000; Prinz 2002) or prototypes (e.g. Rosch 1978; Smith and Medin 1981). 25 In the context of this paper, I will assume that perceptual content is at least in part conceptually structured. The view of content I defend can be modified to include nonconceptual content while leaving the basic structure intact. Showing just how this can be done will require a paper of its own. Even if content is conceptually structured, the state of experience can be understood to be nonconceptual insofar as it is possible to be in the state with content C without having the ability to articulate the concepts that constitute C. So on the defended view, perceptual experience can be understood to be nonconceptual on one common understanding of the notion. For a defense of the (non)conceptual state/(non)conceptual content distinction, see Heck 2000, 484f. For a critical discussion of the thesis that perceptual content is conceptually structured, see Peacocke 1994. The idea that one can fail to be able to articulate the content of one's experience despite possessing the concepts that constitute this content is best explained by example. Given the notion of concept in play it is unproblematic to attribute basic spatial concepts to cats insofar as cats have the ability to distinguish for 38 S. Schellenberg 123 The Fregean gappy content view explains the possibility that when one hallucinates an object it can seem to one as if one is perceiving a particular object. Concepts ground the ability to refer to mind-independent objects and propertyinstances irrespective of whether these objects and property-instances are in fact present in the environment of the experiencing subject. One can employ a concept while failing to refer to what the concept purports to pick out. If the relevant mindindependent objects or property-instances are not present, one fails to refer. As a consequence, the concepts employed remain empty and the ensuing content is gappy. The intentional directedness to an object is accounted for by the mode of presentation in the object-place. While the gap marks that there is no relational particularity, the gappy mode of presentation accounts for the phenomenological particularity of the experience. So on the view I am suggesting, hallucinations and perceptions share a common element, namely de re modes of presentation types. These modes of presentation types just are the concepts employed. As I will argue in §5, the phenomenology of experience is best thought of as supervening on content. More specifically, any experience in which the same concepts are employed in the same sensory mode will have the same phenomenology, regardless of what object (if any) the subject is related to. Insofar as an experiencing subject can employ a concept even if she is not in an environment that contains the object or property-instance that the concept purports to pick out, employing concepts is independent of objects and properties. As a consequence, subjectively indistinguishable experiences share a content element that is independent of objects and properties. The common element is constituted by the concepts employed, that is, by de re mode of presentation types. So objectdependence is not an essential feature of object-related de re modes of presentation. Although a part of the content is object-dependent in the case of a perceptual experience, the very same type of de re mode of presentation can be tokened if no object is present. The token content of the hallucinatory experience is naturally not object-dependent.26 I have argued that the content of a successful perceptual experience depends (at least in part) on what it is about and that subjectively indistinguishable perceptual and hallucinatory experiences share a de re mode of Footnote 25 continued instance between one object being above rather than below a second object or one object being to one rather than the other side of a second object. If this is right, then it is plausible to say that cats possess such basic spatial concepts despite the fact that they do not have the tools to articulate the content of their perceptions. Similarly, it is plausible that we possess perceptual demonstrative concepts that ground our ability to pick out features of our environment, such as the particular vivid and varied color play of a lush forest, without having the tools to fully articulate the content of our perception when we see such a lush forest. 26 It will be helpful to distinguish this way of thinking about perceptual content from Peacocke's early view of content (1981, in particular p. 189f. and p. 197). According to Peacocke, there is no token mode of presentation if there is no reference: token modes of presentation are fully object-dependent. So on his view, hallucinatory mental states would be characterized only by a content type, not by a content token. In contrast, I have argued that hallucinating subjects are in mental states with a token content, but this token content is defective insofar as it is gappy. So on my view, token contents are not necessarily objectdependent. Only a part of the token content of a successful perceptual experience is object-dependent. The particularity and phenomenology of perceptual experience 39 123 presentation type. I have identified this de re mode of presentation type with the concepts employed in experience. One might object that (gh) is not an adequate way of characterizing the content of a hallucination since it cannot account for the fact that the content of a hallucination is inaccurate: given the presence of a gap in the content, the content cannot determine an accuracy condition. In order to respond to this objection, it is necessary to distinguish two ways that a content can be inaccurate. One way is for the content to make a claim about the situation that is not accurate. A second way is for it to fail to make an accurate claim about the situation. To illustrate this second sense of inaccuracy, suppose that I claim that Pegasus lives in my house. This claim is inaccurate. Given that ''Pegasus'' does not refer, the inaccuracy in question is that I have failed to make an accurate claim about the situation. Applied to experience, the idea is that in the case of a (non-veridical) hallucination it seems to the hallucinating subject as if she is related to an object. Since the relevant object is not present, she fails to be so related. As a consequence, she is suffering a presupposition failure. She is mistaken in her assumption that she is perceptually related to the object that it seems to her is present. If inaccuracy is understood in this second way, then a hallucination can have a gappy content and nonetheless be inaccurate. On this understanding of gappy contents, the fact that a content is gappy implies that the content is necessarily inaccurate.27 While the token gappy content of a hallucination is necessarily inaccurate, the relevant content type could be either accurate or inaccurate. As I have argued, subjectively indistinguishable experiences have the same content type, but the token content covaries with the environment of the experiencing subject. Depending on the environment of the subject, the very same content type is either accurate or inaccurate. A content-token is guaranteed to be accurate as long as it is not gappy, while a gappy content token necessarily fails to be accurate insofar as it fails to make an accurate claim of the world. On this view, there is nothing veridical about so-called ''veridical hallucinations''. In such a case, a subject is hallucinating but her environment happens to be just the way she hallucinates it to be. Since the subject is not perceptually related to the object that it seems to her is present (and coincidently happens to be present) the content of her experience is gappy. Indeed, the content of subjectively indistinguishable hallucinations will be the very same-even if one hallucination is nonveridical and the other a so-called ''veridical hallucination''. Now, we rejected the Russellian gappy content view on grounds that it cannot account for hallucinations of uninstantiated properties without making controversial phenomenological and metaphysical commitments. How can the Fregean gappy content view account for such hallucinations? On the suggested view, the content of a hallucination of supersaturated red can be analyzed as a result of jointly employing the concepts of redness and saturatedness, thereby inducing an 27 For a dissenting view of the truth-value of gappy propositions, see Everett 2003. 40 S. Schellenberg 123 experience of a particularly saturated red.28 By contrast to Russellian gappy contents, this approach does not require that experiences of uninstantiated properties are analyzed in terms of awareness or acquaintance relations to the relevant uninstantiated properties. For on the notion of concepts in play, possessing a concept is to have the ability to refer to the external, mind-independent objects or property-instances that the concept is of. Since the content of hallucination is constituted by empty concepts rather than the naked properties that the experience is seemingly of, the content can be analyzed without any appeal to uninstantiated properties. So on the suggested view, there is no reason to think that one must stand in an awareness or an acquaintance relation to the property of being supersaturated red when having a hallucination of supersaturated red. Before I proceed to showing how the Fregean gappy content view grounds the particularity and phenomenology of perceptual experience, I will consider two potential competitors to the suggested view. One might argue that there is no reason to appeal to gaps to account for the content of hallucinations. An alternative solution is to say that the gaps are filled by intentional objects. On such a view, experience is a matter of representing properties that are ascribed to intentional objects.29 These intentional objects can be thought of as existing abstracta or as non-existing concreta. I take such a view to be an alternative to the suggested view, however, I take it to be less attractive for two reasons. One reason is that if hallucinations are construed as relations between subjects and intentional objects, then one is pressed to construe perceptions as relations between subjects and intentional objects as well. However doing so leads to well-known problems.30 A second reason is that positing intentional objects does not bring about any explanatory gain over the suggested view with regard to the phenomenology of experience, while being less powerful in explaining both the relational particularity of perceptions and the absence of relational particularity in hallucinations. I have argued that perceptual experience plays multiple explanatory roles and that perceptual content should be understood as serving multiple explanatory purposes. More specifically, I have argued that experiential content has both a component that grounds phenomenology and a component that accounts for the relation to the perceived object. An alternative way of satisfying these two explanatory roles is to argue that experience has multiple layers of content. On such a multiple contents view, different layers of content satisfy the two explanatory roles. I take such a view to be the most powerful alternative to the gappy content view. So I will elaborate on how the two views compare. There are many reasons to introduce multiple layers of content. My argument, if right, undermines at least one 28 For a detailed discussion of this set of issues, see my forthcoming-b. An alternative way to account for a hallucination of supersaturated red within the framework provided is to analyze it as a result of employing the concept of red, while extrapolating from perceptions of red with regular levels of saturatedness. 29 For different versions of such a view, see Lycan 1996 and Crane 1998. 30 For a recent discussion, see Loar 2003. Loar argues that a view on which perception is construed as a relation to an intentional object is phenomenally implausible. For a discussion of the skeptical problems that ensue if the content of mental states is understood as constituted by intentional objects or relations to intentional objects, see for instance Brewer 1999. The particularity and phenomenology of perceptual experience 41 123 motivation, namely the motivation that one layer grounds phenomenology while another layer accounts for the reference-fixing role of perceptual experience. I will focus on those versions of the multiple contents view that are motivated by this concern. Among these, there are many ways of thinking about the different layers of content. According to Horgan and Tienson (2002), one layer is a narrow content, while the other is a wide content. Subtleties aside, Chalmers (2006b) argues that one layer is a Fregean content that is associated with a primary intension, which is a function from centered worlds to extensions; while the other is a Russellian content that is associated with a secondary intension, which is a function from uncentered worlds to extensions. What these views have in common is that one layer grounds the phenomenology of the mental state, while the other determines the reference of the mental state. The Fregean gappy content view is motivated by many of the same concerns as the multiple contents view, but it does not entail the multiple contents view and it is not a particular version of that view. The multiple contents thesis entails that experience has different sets of accuracy conditions associated with the different layers of content. The thesis that experience has multiple explanatory purposes involves no such entailment: on the Fregean gappy content view, any experience has only one content and thus only one accuracy condition. So the suggested view provides a way of satisfying the different explanatory roles of perceptual content without introducing a second layer of content. As the second difference between the two views will show, there are powerful reasons to resist introducing different layers of content to account for the different explanatory roles of perceptual content. In contrast to the multiple contents view, the suggested view is a view of both the constituents of perceptual content and of what holds these constituents together. It takes seriously Frege's insight that senses play a dual role: they have a cognitive significance and they determine a reference-at least in the successful case. On the multiple contents view, the cognitive significance and the reference-determining role of expressions are accounted for on different levels of content. All subjectively indistinguishable contents will have the same content on one level, but depending on the environment they may have a different content on the other level. The relation between the phenomenal content and the perceived object is simply the semantic relation of satisfaction. A view that thinks of perception as the co-instantiation of two independent elements is a version of what I called conjunctivism. It is a version of conjunctivism on which the relational element is not simply a perceptual relation between a subject and an object, but rather constitutes an object-dependent layer of content. In contrast to the simple version of conjunctivism that I considered in §3, the multiple contents view can account for relational particularity since one level of content is objectdependent. However, since the layer of content that accounts for relational particularity is independent of the layer of content that grounds phenomenology, the questions arise as to how phenomenal contents are connected to what they are about. Consider Chalmers's epistemic two-dimensional semantics. As Chalmers notes, ''primary intensions do not determine extensions in a strong sense (although they may still determine extension relative to context)'' (2006b, p. 596). The layer of content that grounds the phenomenology of the experience does not itself determine 42 S. Schellenberg 123 an extension. Chalmers considers the possibility of accounting for the referencedetermining role of senses by stipulating that the sense of an expression-token is an ordered pair of its primary intension and its extension (p. 596). Although such an ordered pair plays the role of determining reference, it does so trivially given that the extension is part of the ordered pair. The question remains how the primary intensions, that is, the phenomenal contents, are connected to what they are about. Being in a perceptual state is not just a matter of conceiving of an object and (in the successful case) being causally related to that object. Arguably, something is required that connects the content to a subject matter by some non-attributional means. On the suggested view, concepts fulfill the role of connecting mental states with their objects. They ground phenomenology and account for the referencedetermining role of Fregean senses by relating a representation with a nonrepresentational element, that is, a mind-independent object or a property-instance. So on the suggested view, it is part of the very nature of concepts to play both roles and the two roles are interdependent. Therefore, an object-related de re mode of presentation cannot be identified with an ordered pair of a de dicto mode of presentation and a referent.31 The view I have defended is fundamentally representational insofar as both perceptual and hallucinatory experiences have content. The view is fundamentally relational insofar as a perception has the particular content it has because the experiencing subject is perceptually related to a particular object. Moreover, insofar as the content of experience is constituted by concepts the possession of which grounds the ability to refer to objects and property-instances, relations to objects and property-instances are implicated in the very nature of experiential content. In the next section, I will show how the suggested view grounds the particularity and phenomenology of perceptual experience. 5 Grounding the particularity and phenomenology of perceptual experience In the last section, I argued that perceptual experience is fundamentally both relational and representational. More specifically, I argued that the content of experience is constituted by object-related de re modes of presentation and analogous modes of presentation of property-instances. In this section, I will show how the suggested view can combine the virtues of relationalism and representationalism, while avoiding the difficulties of the austere versions of these views. 31 To deny that the content can be identified with such an ordered pair is not to deny that the content can be analyzed into two layers: one of which is object-dependent, the other of which is object-independent. However, the ability to analyze A in terms of B, does not imply that A is identified with B. It would lead well beyond the scope of this paper to discuss this set of issues in detail here. For a defense of the thesis that de re contents cannot be reduced to de dicto contents and referents, see Evans 1981. For a recent critical discussion of two-dimensional semantics, see for instance Speaks 2009. It should be noted that a defender of the multiple contents view could understand one of the layers of content as potentially gappy and thus synthesize the gappy content view with the multiple contents view. Arguably, a gappy multiple contents view (that is, a view on which one layer of content is potentially gappy) would face the very same problems as a simple multiple contents view (that is, a view on which no layer of content is gappy). The particularity and phenomenology of perceptual experience 43 123 Austere relationalists argue that perceptual experience is fundamentally a relation to an object. The suggested view accepts this central relationalist insight insofar as perceptual content is understood to be inherently relational. What does it mean for content to be inherently relational? If perceptual content is constituted by concepts and possessing a concept is understood in terms of an ability to refer to the objects or property-instances that the concept is of, then relations to objects and propertyinstances are implicated in the very nature of perceptual content. Moreover, if the fact that concepts pick out objects and property-instances in some environments and not in others has any semantic significance, then the content ensuing from employing concepts will depend at least in part on the environment in which they are employed. Since perceptual content is in part dependent on the objects perceived, the suggested view allows for a straightforward way of accounting for the relational particularity of perceptions. The particular object to which the subject is perceptually related secures the relational particularity of her experience. So there is a difference between the contents of perceptions of numerically distinct but qualitatively indistinguishable objects. If a subject sees a white coffee cup and without her noticing the cup is replaced by a qualitatively indistinguishable cup, then the content of her experience changes despite the fact that this change is not reflected in her phenomenology. The content of the experience changes since it is constituted by a de re mode of presentation of a different object. So what the suggested view shares with relationalism (that austere representationalism lacks) is that it can account for relational particularity. However in contrast to austere relationalism, the view can easily account for the phenomenology of a hallucination. The suggested view accepts the central representationalist insight that experience is fundamentally a matter of representing objects and properties, regardless of whether these objects and properties are present. As a consequence, it allows for a straightforward way of explaining what accounts for the subjective indistinguishability of a hallucination and a perception. In subjectively indistinguishable experiences, the same concepts are employed in the same sensory mode. The phenomenology of experience can be identified with employing concepts in a sensory mode.32 Concepts can be employed even if they fail to refer. So in contrast to disjunctivism and austere relationalism, I am arguing that hallucinations share a common element with subjectively indistinguishable perceptions. Whether or not a concept is empty will not affect the phenomenology of the experience. Only if this is the case, can the view satisfy the indistinguishability desideratum. For only if it is not revealed in phenomenology whether a concept is empty or not can a perception and a hallucination be subjectively indistinguishable. So with representationalists but against austere relationalists, I am arguing that the phenomenology of experience reflects only phenomenological particularity. However in contrast to austere representationalism, the suggested view does not equate perceptual content with phenomenal content and as a consequence can 32 Alternatively, one could argue that only part of phenomenology is identified with employing concepts in a sensory mode so as to leave room for aspects of phenomenology-such as blurriness and afterimages-that do not supervene on content. For a recent defense of the view that such aspects of phenomenology are best not understood as supervening on content, see Peacocke 2008. 44 S. Schellenberg 123 account for relational particularity. Although mode of presentation types remain the same across subjectively indistinguishable experiences, token modes of presentation covary with the environment in which the subject experiences. As a consequence, there can be differences in content that are not reflected in phenomenology. While the suggested view rejects the austere representationalist thesis that perceptual content is phenomenal content, and consequently is not compatible with so-called strong representationalism, it is compatible with weak representationalism. If a distinction is drawn between what an experience is of and what one takes one's experience to be of, then we can drive a wedge between the content and the phenomenology of an experience, without thinking of them as entirely independent. By driving a wedge between phenomenology and content one can account for the possibility that a perception and a hallucination are subjectively indistinguishable while accounting for their differences that are due to the experiencing subject being related to different environments (or not being related to any environment). 6 Conclusions Views according to which perceptual experience is fundamentally relational have been taken to be in conflict with views according to which perceptual experience is fundamentally representational. I have argued that the two views can be synthesized, if the content of experience is understood in terms of potentially gappy object-related de re modes of presentation. The content of a hallucination is constituted by tokens of the same types of de re mode of presentation as the content of a subjectively indistinguishable perceptual experience. As I have argued, objectrelated de re modes of presentation fulfill the role of both grounding phenomenology and relating mental states with the environment to which experiencing subjects are intentionally directed. The suggested view preserves the best features of both relationalism and representationalism, while avoiding the problems of the austere versions of these views. By equating perceptual content with phenomenal content, the austere representationalist argues that the content of two subjectively indistinguishable experiences is necessarily the same. As a consequence, the view cannot account for relational particularity. By contrast the austere relationalist can easily account for relational particularity. However since he does so by understanding the phenomenology of experience as individuated by what the experiencing subject is perceptually related to, his view faces a dilemma. Either he must accept the counterintuitive consequence that perceptions of numerically distinct but qualitatively indistinguishable objects differ with regard to their phenomenology, or he must accept that phenomenology is multiply realizable. If the austere relationalist takes the second option, he can argue that perceptions of numerically distinct but qualitatively indistinguishable objects have the same phenomenology, however, he can no longer appeal to phenomenology to account for relational particularity. As I have shown, this dilemma is circumvented if one accepts that perceptual experience has content and that it is the content rather than the phenomenology of perceptual experience that accounts for relational particularity. The distinction The particularity and phenomenology of perceptual experience 45 123 between phenomenological and relational particularity that I introduced paved the way for a view of perceptual experience on which the difference between perceptions of numerically distinct but qualitatively indistinguishable objects is reflected in the content of experience, but not in its phenomenology. Moreover, the suggested view makes it possible to acknowledge that a perception and a subjectively indistinguishable hallucination differ in content, while acknowledging that they have a common element. Subjectively indistinguishable experiences instantiate the same potentially gappy de re modes of presentation, which ground the phenomenology of the experiences. However, since the gap in the content can be filled by different objects (or not filled at all) there is a difference between the contents of these subjectively indistinguishable experiences. So the suggested view of perceptual experience allows one to synthesize the representationalist insight that perceptual experience is fundamentally a matter of representing objects and properties with the relationalist insight that perceptual experience is not simply a matter of cognitive contents becoming subjectively available. Acknowledgements This article has a long history and so I am indebted to an unusual amount of people. I thank Keith Allen, Kent Bach, Alex Byrne, Herman Cappelen, David Chalmers, Bill Fish, Jim John, Heather Logue, Gurpreet Rattan, Jonathan Schaffer, Susanna Siegel, Daniel Stoljar, Crispin Wright, and Wayne Wu for discussions and comments on a draft of this paper. Particular thanks are due to John Campbell and Terry Horgan who both commented on this paper at a refereed symposium at the APA Pacific Division meeting 2008. 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