Conscious Unity (Paul Raymont, praymont@gmail.com 2005) 1. Introduction My consciousness covers a diversity of content. I feel a back pain, see the characters on the computer screen, and hear the noise of the traffic outside. This multiplicity is accompanied by a unity, for my conscious condition is not just an aggregate of discrete experiences of the noise, the screen, and the pain taken singly. Rather, I am aware of these things together by means of a single experience. Borrowing a term from William James, they are co-conscious for me (James 1909/1967: 221). 2. The Experiential Parts View According to one view, the experience whereby I am conscious of many things includes simpler experiences of the contents. For example, my experience of the pain and the noise includes an experience of just the pain, and an experience of just the noise. These simpler experiences are the relata of co-consciousness, and are linked together as parts of the unified experience of the pain and noise. In short, experiences a and b are united in a third experience, c, which is their joint occurrence. Call this doctrine, the view that a synchronically unified experience has as its parts other, co-conscious experiences, the Experiential Parts View (EPV). Among the adherents of EPV is Michael Lockwood, who introduces the notion of co-consciousness as "the relation in which two experiences stand, when there is an experience of which they are both parts" (Lockwood 1989: 88). Similarly, Barry Dainton says, "The relata of co-consciousness are experiences" (Dainton 2000: 88), and speaks of co-conscious experiences as "component parts" of the "total experience" that results from their linkage (Dainton 2000: 214). Sydney Shoemaker also appears to endorse EPV when 2 he says, "The experiences are co-conscious ... by virtue of the fact that they are components of a single state of awareness whose objects are events perceived by the subject" (Shoemaker 2003: 65). 1 EPV is false. The conscious mental act through which diverse contents are presented does not have other conscious states, experiences, as parts. Call this the No Experiential Parts View (NEPV). 3. The No Experiential Parts View NEPV is advanced by John Searle (2002). He ventures the hypothesis that "it is wrong to think of consciousness as made up of parts at all" (Searle 2002: 56). He adds that while my unified conscious state includes visual aspects in addition to qualities peculiar to other perceptual modalities, "there is no such thing as a separate visual consciousness" (Searle 2002: 55). 2 Michael Tye offers a similar view, which he dubs the 'one-experience view' (2003: chap. 1). Considering the polymodal nature of our experience, he says, "There are not five different ... experiences somehow combined together to produce a new unified experience" (Tye 2003: 27). Instead, "there is just one experience here" (Ibid.). An earlier version of NEPV was championed by William James (1890). He endorses NEPV in the course of repudiating the 'mind-stuff theory', according to which "our mental states are composite in structure, made up of smaller states conjoined" (James 1890: 145). Against this, he says that while our experience is complex, this complexity is not a matter of there being several experiences (or 'feelings') present in an encompassing experience. 3 This is because "we cannot mix feelings as such, though we may mix the objects we feel, and from their mixture get new feelings" (James 1890: 3 157). If one's experience seems to become more complex, that is a matter of its content becoming more complex and is not the augmentation of one's state of mind by more experiences. Putting James' view in terms of co-consciousness, only contents, not the experiences of them (or 'feelings'), are the relata of co-consciousness, and the contents are made co-conscious by being presented together in the same, single experience. If we say that experiences a and b are fused to form c, we should treat 'fused' as referring to a process in which a and b are superseded by, not included in, c. They have disappeared and been replaced by c, in which their contents (not they themselves) are connected. As James put it, using the contrast between consciousness of the whole alphabet and the several states required for being aware of each of the letters taken singly, "It is safer ... to treat the consciousness of the alphabet as a twenty-seventh fact, the substitute and not the sum of the twenty-six simpler consciousnesses" (James 1909/1967: 189; emphasis added). 4 To clarify NEPV, let's use the notation `E(o1)' for an experience that is the conscious representation of just the intentional object o1. A conscious representation of just o2 is E(o2). What is the nature of an experience that takes the broader content in which o1 and o2 are presented together? Proponents of NEPV take this experience to have the structure of E(o1, o2), where this introduces a solitary experience that takes the whole content in its scope. No 'smaller' or simpler conscious states figure as parts of E(o1, o2). This experience may be a brain state that has parts, but these parts are not further conscious states. 4 On NEPV, the subject does indeed have an experience of o1, but it has the form of E(o1, o2), and so is such that to be conscious of o1 by means of that experience is also, by that very mental act, to be conscious of o1 with o2. This is what the subject's conscious unity at the time amounts to (if we oversimplify by supposing her to be conscious of nothing but o1 and o2). 4. The Failure of EPV It is unclear what support there is for EPV. Perhaps its supporters take it to be obvious, supported by a strong intuition, so that the onus is on those who would deny it. However, the intuition behind EPV is confused. To see why, suppose that experience d is a unified conscious state by means of which one is conscious of o1 and o2. Supporters of EPV confuse the untokened experiential type, E(o1), which takes part of d's content as its sole content, with one of that type's tokens, which is held to be present as part of d. But there is no reason to suppose that there is any such distinct, additional experience nestled in d. 5 In support of NEPV, consider an act of reference as an analogy. Suppose I refer to Toronto. Scarborough is part of that city. It does not follow that my act of referring to Toronto contains a numerically distinct reference to Scarborough. The mere fact that Scarborough is part of the thing to which I refer does not entail that a reference to just that borough figures as part of my act of referring. Similarly, the mere fact that o1 is represented in the content, (o1, o2), does not entail that a distinct representation of just o1 must figure as part of my act of representing (o1, o2). Not only does EPV stand in need of support, but it faces a difficulty that does not beset NEPV. James describes the problem in his example of the twelve-word sentence. 5 Suppose each word in the sentence is known by just one of twelve people. It is hard to see, James says, how the twelve thoughts could be combined to yield "a consciousness of the whole sentence" (James 1890: 160). What EPV so far lacks is a way of putting together experiences that also puts together their contents. Without any specification of how this combining of contents is to be achieved, we are left with a mere aggregate of experiences, each member of which is oblivious to the contents of the other states in the aggregate. As James says, "Idea of a + idea of b is not identical with idea of (a + b)" (James 1890, p. 161). A mere combination of experiences is not the experience of a combination. In my notation, the problem is that putting together two experiences that have the forms respectively of E(o1) and E(o2) gives us an experiential aggregate of the form [E(o1), E(o2)], without a single conscious state directed at the whole content. By contrast, in an experience of the form, E(o1, o2), all the represented objects fall within the purview of a single conscious state, and this is accomplished without any more than one experience. The difficulty for EPV, then, is not that it is a more complicated or awkward account of synchronic conscious unity than NEPV. Instead, the problem is that EPV simply fails to yield any account at all. If our aim is to make sense of the fact that one is conscious of a variety of contents together in one conscious state, then endorsing EPV introduces no progress towards our goal. A defender of EPV might reply by introducing an experience, d', which has the form, E[E(o1), E(o2)]. Since d' is an experience of other experiences (viz., E(o1) and E(o2)), it is a higher-order experience (HOE), one that fits both o1 and o2 in its scope. 6 However, proponents of EPV typically do not endorse a HOE model of our normal, unified conscious states; they want to allow for the possibility of being in such a state without having a higher-order representation of it, a possibility that can be realized only by an experience of the form E(o1, o2). Also, it would be odd if the only way to be conscious of various items (e.g., o1 and o2) were by being conscious of discrete experiences of each such thing on its own (E(o1) and E(o2)). Even when I reflect on my unified experience, as opposed to its objects, I am aware of one state in which the various objects are presented together, not several experiences in which they are each presented singly. 5. NEPV and Transparency Tye weds NEPV to the view that conscious states are transparent, where this means that the qualities of which I am conscious are not had by the conscious state itself but are merely qualities that are represented. In his words, "Phenomenal unity is a relation between qualities represented in experience, not between qualities of experiences" (Tye 2003: 36). He invokes transparency in response to the following objection to NEPV (Tye 2003: 33). Suppose that I hear a conversation while looking at a bed of roses. That same auditory experience, it seems, could have occurred without my seeming to see the roses. This suggests that my actual auditory experience is a distinct, even separable part of my polymodal experience, which supports EPV. Tye replies that when I try to turn my attention inward to observe the features of the auditory experience, I at best become aware only of "the auditory qualities the experience represents" (2003: 33). Introspection will thus show me what my experiences 7 are of but not what they are in themselves. But if it does not show me what intrinsic properties two experiences have, then it is an insufficient basis for identifying them. So it does not suffice as a basis for identifying the experience of just the conversation with some part of my actual polymodal experience. Contrary to what Tye suggests, the appeal to transparency is not required in order to meet the objection. We can defend NEPV while holding that some of the qualities of which I become aware in having a conscious state belong to the experience. The fact that the possible experience, the one in which I hear the conversation without seeing roses, resembles my actual experience in some respect does not establish the presence in the latter of a separable part that resembles the possible experience in every respect. Again, while an experience of the form E(o1) resembles in some way an experience of the form E(o1, o2) (by, say, presenting o1in a certain auditory way), that does not entail the presence in the latter of a distinct token which exactly resembles the first state. This rejoinder requires no denial that some of the features of which I am aware in having a given experience are qualities of the experience itself. 6. Perceptual Incompatibilities Tye considers another possible objection to NEPV, arising from the fact that we can seem to perceive mutually incompatible states (2003: 38). How could a single experience alone do all the work of presenting the incompatible features? Without going into Tye's response, I will argue that reflection on perceived inconsistencies supports NEPV. Examples in which one perceives incompatible features can be found by considering properties that can be detected by more than one perceptual modality. 8 Consider the bent-stick illusion. 6 Suppose I visually experience the stick as being bent at position p at t, but tactually experience it as being not-bent at p at t. 7 Here, the very same thing is represented as both having and lacking a certain property. Some kinds of incompatibility cannot be accommodated within a subject's consciousness at a time. It is easier to find such examples by confining ourselves to one perceptual modality. I cannot at once visually represent a stick to be both bent and not bent at p at time t. One might be tempted to account for this by saying that the content contains a contradiction and therefore cannot be perceptually represented. The (putative) state of affairs in which the stick is bent and not bent is inconsistent, and that is why it cannot be depicted in my perceptual experience. But this won't work, for I can represent this contradiction in the content of my polymodal experience. I conjecture that instead of adverting to the content of the mental state, to features that it merely represents and does not itself have, an explanation of why I cannot visually represent the stick as bent and not bent must advert to intrinsic features of the mental state, to how it does the representing. The fact that the mental state cannot present the stick as bent and not bent in the very same portion of the visual field indicates a limitation on the properties of the mental state itself, as distinguished from features that it merely represents. It indicates the prohibition of contradictions not in states of affairs merely represented by the state but, instead, in the nature of the mental state itself; the mental state cannot do two mutually exclusive things at the same time (e.g., representing in two incompatible ways). There is nothing mysterious about why it cannot do so. It cannot do so simply because nothing can possess two mutually incompatible properties at the same time. Just as I cannot be both five feet tall and six feet tall at the same moment, 9 so too no mental state can encode in the same portion of the visual field both that the stick is bent and that it is not bent. In short, while an experience can represent incompatible features (as in the bent stick illusion), it cannot have incompatible features. These observations support NEPV and threaten the transparency theory. They threaten transparency insofar as they suggest that the incompatible features that cannot be accommodated in one's conscious state (e.g., encoding a bend in some portion of the visual field) are, when separately instanced, features of experiences themselves. At the same time, they are features of which I am conscious when I see the stick as straight or as bent. So, contrary to transparency theory, if I see the stick as bent, at least one of the features of which I become conscious in having that experience is a feature of the experience itself. The lesson is that perceptual incompatibility cannot be explained by appeal just to an incompatibility that is merely represented by the experience. The explanation of the incompatibility, one that does not run afoul of the bent-stick example, is simply that no single thing can simultaneously possess mutually exclusive properties; and representing a bend in the stick in one part of the visual field excludes representing a straight stick in that portion of the field. No single experience can have both these features at once. This supports NEPV, for the explanation that I have offered applies only if we really are talking about just a single experience. If not, if my experience is composed of several simultaneous experiences, then we could not avail ourselves of the above explanation of the perceptual incompatibility. For if there were several constituent experiences, the incompatible properties could be distributed among them (just as something can include round parts and square parts even though it cannot itself be round 10 and square). That is, there would be several conscious states, each one of which could bear one, and only one, of these mutually incompatible properties – one visually representing the stick as straight, another visually representing it as bent. The explanation of perceptual incompatibility that I have advanced is, then, available to us only if we say that there is in fact just one conscious representing state, a single entity that cannot possess mutually exclusive properties at the same time. It may be objected that this, at most, shows only that there must be a single representational state by means of which I am aware of the various contents, but that this is perfectly compatible with that state's containing other conscious states as parts. Against this objection, recall that the single conscious state that supposedly includes other such states as parts cannot have the form, [E(o1), E(o2)], for that is a mere combination of representations without a representation of combination. So the critic must revert to the higher-order experience, d', of the form, E[E(o1), E(o2)]. Suppose she could somehow establish the presence in d' of two tokens, a and b, having respectively the forms of E(o1) and E(o2). Even so, d' is not itself a visual representation of a and b. I do not see (or even seem to see) a and b by means of the higher-order state. So d' has no visual phenomenology of its own. Instead, whatever visual character is to be found in this case resides wholly in the lower-order states. Thus, suppose that these states, a and b, are in fact visual representations. We have been given no reason why one of them could not visually represent the stick as being bent while the other visually represented it as not being bent. So, the explanation of perceptual incompatibility that I have offered would not be available, for there is here no single mental state that we could point to in explaining the incompatibility by saying that it (that one state) cannot simultaneously 11 have the incompatible properties of visually representing the stick to be bent and visually representing it not to be bent. Instead, there is the representation, a, which visually represents the stick as bent; and the representation, b, which visually represents the stick as not bent; and the HOE, d', which does not visually represent anything at all. In short, on this model the two mutually excluding features are parceled out between two mental states, so that it is unclear why they should exclude each other; and the HOE (through which the lower-order states are supposed to be combined) could not itself be the seat of any such conflict or tension, since it has neither of the mutually incompatible features of visual representation. These observations do not decisively refute EPV, for there may be other explanations of the perceptual incompatibilities. Still, I hope to have advanced some considerations in favour of NEPV by showing that it offers a simple and very plausible – dare I say, the best – explanation of the incompatibilities, one that is not available if we opt for EPV. NOTES 1 Michael Tye cites Tim Bayne and David Chalmers as proponents of EPV (though he does not use this label) (Tye 2003: 21). However, Bayne and Chalmers use subsumption instead of co-consciousness as the key relation, and it is not clear that the account that results is a version of EPV. While it is true that they speak of the encompassing conscious state as involving "at least a conjunction of each of many more specific conscious states" (Bayne and Chalmers 2003: 27), and of a "complex phenomenal state and a simpler state that is intuitively one of its components" (2003: 40), they also caution that thinking here in terms of "a mereological part/whole relation among phenomenal states" should be regarded only as an "aid to intuition rather than as a serious ontological proposal" (2003: 40). So it is not clear how their view should be classified. 12 2 After asking whether "the visual experiences stand to the whole field of consciousness in the part-whole relation," Searle answers that they do not (2002: 54). 3 Indeed, he says, "We cannot even ... have two feelings in mind at once" (James 1890: 157). 4 In his (1909/1967), James abandoned the approach that he took in his (1890). I will not go into his reasons for doing so. 5 This is similar to some considerations adduced by Tye (2003: 25-41). However, he develops his case in terms of constitution, focusing on cases in which there is some stuff that could on its own have constituted (e.g.) a pot, but does not do so because it is actually enveloped in more stuff. The problem is that it is not clear that the stuff (e.g., the brain state) that would have constituted an experience of just o1 is actually present at all in d, and only fails to constitute an experience of just o1 owing to its envelopment in d. Tye maintains that the cluster of brain events that could (but does not) constitute an exclusively visual experience is part of the brain state that constitutes one's actual polymodal experience (2003: 31-33). He is thus led by his theory to make a claim about the structure of neurological states. But it is surely possible, and is compatible with my model of conscious unity, that the brain state required for a purely visual conscious state is wholly replaced by, not included in, the brain state that subserves one's actual polymodal conscious condition. 6 Bayne (2000: 249) and Tye (2003: 38) both consider this case in connection with conscious unity. 7 As Tye notes (2003: 179 n. 10), touch corrects vision here, leading one to come to see the stick as straight. But conceptually there is no obstacle to supposing that it did not. LIST OF REFERENCES Bayne, T. (2000) The Unity of Consciousness: Clarification and Defence. Australasian Journal of Philosophy 78: 248-54. 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