AS EXISTENCE AGAIN
by Ted Honderich
was a paper
for the World Congress of Philosophy, Boston, the session with William
Lycan and David Rosenthal. It was published in the good journal Theoria
(June 2000) and will also be in the proceedings of the World
(1) It cannot be a string of only neural or electrochemical events. This old materialist answer, the eliminative kind, although still with us, surely leaves something out, a lot.
(2) Does it help to say instead that your being perceptually conscious is a string of events such that each of them is one thing with both neural and other properties? This different and lenient sort of doctrine is spoken of as physicalism, the mind-brain identity theory and monism, and, more enlighteningly, as event-monism. It calls out for completion by an adequate account of the other properties, the ones in which your perceptual consciousness evidently consists. Let us suppose, however, that event-monism when completed will still be somehow physicalistic.
(3) Is there an answer to the question of the nature of your perceptual consciousness in the varieties of neural functionalism -- functionalism as limited to our species? Here, perceptual consciousness consists in causal relata that are only neural. Despite intending to preserve rather than eliminate consciousness, by way of the idea of variable realization, neural functionalism seems like eliminative materialism in leaving a lot out. Certainly an event of your perceptual consciousness, that event, does not acquire more than its neural properties by the consideration that causally speaking it might instead have had other than neural properties. (4) Finally, it now seems desperate to say that perceptual consciousness is physical properties in your head, properties not now known in neuroscience but somehow different properties that may be discovered in some future science. It is all too possible to anticipate that such discoveries would be taken as still leaving a lot out.1
These four seemingly failing accounts all have the good recommendation of naturalism. This cannot be philosophically well understood as belief in only whatever things are allowed to exist in science, along with a commitment to scientific method. This characterization of naturalism is uninformative -- it gives only a signpost to the things rather than their nature. It is also an uncertain signpost, if only for the reason that psychology is within science and there is uncertainty about what is within psychology. Also, at best, the characterization is vulnerably tied to a current time-slice of science.
A better philosophical understanding of naturalism is belief in only physical things, and in fitting methods of inquiry, of which scientific method is at least the dominant one. As for the physical things, given what has just been said, they must not be weakly identified as the things allowed in science. Let us understand them in something like a standard and traditional way. There are two categories of them, those taking up space and time and having perceived properties, and those unperceived but taking up space and time and standing in causal or other lawlike connection with the perceived things. Sofas go into the first category, atoms and a good deal else into the second.2
There is another account of perceptual consciousness, a speculation that looks at the thing very differently.3 Something new certainly seems necessary in the face of our persistent philosophical failure to get agreement, outside of groups and coteries, on the nature of perceptual and other consciousness. We need a change.4 This particular different account is close to naturalism but not within it -- which particular shortcoming, if such it is, we can leave unconsidered for a while. The spur to the account, as much as the need for a change, is the so-called phenomenology of perceptual consciousness, what is called the way it seems. Here we find the first of what may be taken as four principal constraints on an adequate account of perceptual consciousness.
1. Phenomenology, So-CalledThink again. What is it for you now to be aware of your surroundings? It's for things somehow to exist, isn't it? To speak a little grandly, what it is for you to be perceptually conscious now is for a world somehow to exist, a certain changing totality of things. Mine now consists in things in this room and outside the window. This seems to be the right answer to the question of the so-called phenomenology or seeming nature or appearance of perceptual consciousness. Something more is worth thinking about -- that we here have the most promising conception of actual perceptual consciousness, that we here begin to get hold of its real nature. What it is for you to be aware of your surroundings is for, in a certain sense, there to be certain things with various properties in space and time.
This rough idea is not, anyway in intention, what can be conveyed by saying in a certain manner that what it is for you to be perceptually conscious is for things to exist for you. That is just saying, if somehow evocatively or mysteriously, that standard physical things are in your particular awareness -- in fact are perceived by you. No analytic light would be shed on your being perceptually conscious by saying in this way that things exist for you. To do so, despite the puzzling implications, would be to use the ordinary pre-analytic content of talk about perceptual consciousness. The rough idea, rather, although a person is certainly part of it, is that a claim as to a person's being perceptually conscious needs to be regarded as no more than a kind of claim as to the existence of things, not exactly standard physical things.
Should this view be put aside without further ado as a mistake about perceptual consciousness as it is, the reality of it? A mistake manufactured out of the truth of phenomenology that your perceptual consciousness seems to you to consist in the existence of things outside you in space and time? On the contrary, it still strikes me as plain that perceptual consciousness, like consciousness generally, is something to which the distinction between appearance and reality, and thus talk of phenomenology, does not apply.
Consciousness itself, whatever it is, as many have said in several ways, is what we can non-inferentially report. That much, easily distinguished from additional and weakening suppositions about introspection, infallibility and so on, is hardly disputable. What cannot in this sense be reported is not within consciousness. It must then be merely audaciously inconsistent to speak of something as within or a part of consciousness and also hidden. There are of course bases and structures under consciousness, and causes of it, and theories pertaining to these and other related things, but none of this is to the point. Perceptual consciousness, in short, has only the parts it seems to have and no more. That is not to say, of course, that it does not raise philosophical problems. There is a need for interpretation of what we are given.
Is it the case that all that is reportable of perceptual consciousness is the existence of a world in the way so far suggested? To claim this will seem to be to claim too much, maybe merely audaciously. There has been much talk of a subjective aspect of one's consciousness. There is the role in one's consciousness of what seems half-reportable -- a subject, oneself.5 Let us keep this in mind, but go on with the rough idea we have. It may be that it itself, the idea of a world or totality, will clarify talk of subjectivity.
So -- for you to be perceptually conscious is for things in a way to exist in space and time. I do not take what has been said of phenomenology to have proved the claim, but rather to have redistributed the burden of proof a little. Other defences or virtues of the idea, additional to the need for a new beginning and the consideration having to do with phenomenology, can be brought into view by clarifying the claim of existence. It can be clarified by comparing it with something else.
2. Etherealizing Consciousness, and the Reality of ItThe claim of existence is both like and unlike one part of what more or less standardly or traditionally is meant by saying that there are physical things or that there is a physical world. This part, as already noted, is that there are things occupying space and time, and thereby having shape, size and so on, and also having at least one perceived property. These things are distinct from the second category of physical things. Those have no perceived properties but are spatio-temporal occupants and are in causal or like connection with physical things in the first category.
Part of the likeness between a world of perceptual consciousness and the perceived part of the physical world has to do with the fact that those physical things -- the sofas and the like -- have some dependencies.
Firstly, they depend on or have a necessary condition in something like the first category of physical things, atoms and the like, sometimes itself called the scientific world. This necessary condition is some kind of constitutive condition, although not the only one. The physical things in the perceived part of the physical world, secondly, have a well-known dependency on perceivers in general or some perceivers or other, as distinct from any particular perceiver. The dependency has to do with our neural and perceptual apparatus and more than that. Since, whether or not reportable by a perceiver, the idea of a subject, or anyway some idea of subjectivity, maybe of a point of view, seems necessary to the idea of a perceiver, the physical things in question have a third dependency, on subjects in general or some few subjects, but none in particular.
There are related dependencies of the particular world or totality of things in which, according to my story, your perceptual consciousness now consists. Firstly, it too has a kind of constitutive dependency on entities in the scientific world. Secondly, it has a kind of necessary condition in your own ongoing neural history. Further, your world of perceptual consciousness somehow depends on what we are inclined to call a particular subject, yourself, whether or not it gets into your reports.
We have various impulses about consciousness. One, although not the strongest, is somehow to etherealize it. Partly as a result of this impulse, a predictable objection will be made to the present account of perceptual consciousness. In the objection, the dependencies on particular persons will be relied on in order to try to demote the contents of perceptual consciousness, say your world of perceptual consciousness, from being propertied things out in space and time. The attempt will be made to turn them into a mental world, some totality of thoughts and feelings of an ethereal and thus uncertain nature. A mental world in this sense, further, will likely be located within a cranium.
There is a defence against this demotion of a world of perceptual consciousness in the similarities just noted. Part of the defence is that a dependency on human perceivers in general, including perceivers somehow taken as subjects, does not demote the perceived part of the physical world to anything less than propertied things out in space and time. Also, what somehow stands in the way of any such demotion, a somehow constitutive dependence on the scientific world, also has a counterpart with a world of perceptual consciousness. In the case of each item in a world of perceptual consciousness too, there is a standing necessary condition in the scientific world.
Does demotion threaten again when a further truth about your world of perceptual consciousness is noted, one bound up with the dependencies or necessary conditions already noted? The further truth is that your world has not only a kind of necessary condition in your neural activity, but also a kind of sufficient condition or guarantee.
Well, should a rush to demote your world into a mental world on this account not be be restrained by a certain fact? The other necessary condition of your world of perceptual consciousness, the somehow constitutive one in the scientific world, is a necessary condition of your world of perceptual consciousness in virtue of being a necessary condition of exactly the sufficient condition or guarantee of your world which is your neural activity. It is a little too much to say, but not much, that the chair in your perceptual consciousness is formed, via your neural activity, by the scientific chair.
There is something else to be said. Return to the perceived part of the physical world. A thing in it, as we know, is dependent on a necessary condition in the scientific world, and also on perceivers in general. But here too, although we have not been inclined to notice it, there is a further truth. The two necessary conditions are related in a certain way. The perceived part of the physical world also has a kind of sufficient condition in the perceivers in general -- which sufficient condition is dependent on the scientific world.6
All of which leads to at least a question of why your world of perceptual consciousness should be demoted to the standing of being a mental world. The supposed reasons given have counterparts with the perceived part of the physical world, and those counterparts do not demote the physical things in question.
If the etherealizing and cranializing impulse exists, and can latch onto the personal dependencies, but perhaps can be resisted, there is another stronger and indeed more or less opposite impulse about consciousness that needs attention. It is better called a conviction. It can hardly be resisted, and so the question arises of how it is suited by the account of perceptual consciousness under consideration.
This is the conviction had by most of us that the four naturalistic accounts of perceptual consciousness mentioned at the start leave out a lot. In fact that is to understate the conviction. We are inclined to say that the four accounts leave out a reality, indeed the reality of perceptual consciousness. If they left out only something ethereal, something gossamer, they would not be so unsatisfactory. They would not be so resisted. What they leave out, we say, is not something diaphanous, elusive, peripheral or inessential. When we lose consciousness we do not lose just some gossamer. It's not that you lose touch with what has the reality, but that to lose consciousness is for a reality to end, with luck only for a while.
This talk about reality, loose as it is, seems to me to express a constraint that must be satisfied by any adequate conception of perceptual consciousness. It is the second of four principal constraints. It is satisfied by the conception under consideration. The account suits it down to the ground. Indeed, it is unique in satisfying it, despite some complications that need a moment's attention.
The chair in your perceptual world, although a careless mistake about it is more than possible,7 is not identical with the chair in the perceived part of the physical world. It is not as real as that. Rather, to speak generally, the first chair is in a part-whole relationship with the second chair. As greater and lesser philosophers have said before now, although often after demoting the chair in your perceptual world, it is a constituent, element, side, facet or the like of the chair in the perceived part of the physical world. The latter chair is constructed, so to speak, out of such chairs as yours.8
This does not affect the fact that the chair in your perceptual world is itself in space and time, otherwise propertied, and, as may be added, in causal relations with other such things. In short, the conception of perceptual consciousness under consideration, as a certain totality of existing things, fully accords with our conviction, fully explains the reality we are moved to accord to that consciousness. That reality is constituted by the things. Could anything else do the job?
3. SubjectivityThe conception of your perceptual consciousness as a certain totality of existing things has as great a virtue not in the similarities but in the differences between such a totality and the perceived part of the physical world. Certainly this virtue, the satisfaction of a third principal constraint, will be of the greatest importance in any attempt to build on the conception of perceptual consciousness in order to come to a satisfactory conception of consciousness generally.
This virtue has to do with what has already been mentioned and has long been called subjectivity. Consciousness and perceptual consciousness surely have a subjective character. What this conviction of ours comes to, in very general terms, and to stick to perceptual consciousness, is that there is a fundamental difference between my perceptual consciousness and yours, and also, more important, between either mine or yours and, in Nagel's phrase, a view from nowhere.9 There is, in terms of the account of perceptual consciousness as existence, a fundamental difference between your world of perceptual consciousness and mine, and, more important, between either of them and the perceived part of the physical world, not to mention the unperceived part.
That the four naturalist ideas of perceptual consciousness noticed at the start fail to give an adequate account of subjectivity is as large an objection to them as that they offend against the so-called phenomenology of consciousness and leave out a reality. They are not alone in failing to give an adequate account of subjectivity, by the way. It transpires that an admirable account of consciousness officially opposed to them, Searle's, although naturalistic in inclination itself, shares the failing. Various particular facts of subjectivity enumerated by him, such as the causal dependency of events of perceptual consciousness on a particular perceiver, are facts consistent with neural functionalism, and insufficient as an account of our conviction of fundamental subjectivity.10
The conception of perceptual consciousness under consideration does of course recognize the insufficient facts of subjectivity just mentioned, say the dependency of your perceptual consciousness on your neural states. Also, it gives literal sense not only to one of these ideas, that perceptual consciousness involves oneself as a subject or a point of view, but to the related and more definite idea that a point of view is not merely involved in but is one thing that is constitutive of perceptual consciousness. Your world of perceptual consciousness is a world from a point of view, the latter being where your head is.
There is more to subjectivity, something more fundamental, a larger distinction of perceptual consciousness. This conviction of ours, as it seems to me, is satisfied by the account under consideration of perceptual consciousness as existence. By this account, simply, what each of us has in his or her consciousness is other than the physical world, the world that is objective in not having a dependency on anyone in particular. No world of perceptual consciousness is identical in its contents with the perceived part of the physical world -- or of course the other part. Your world of perceptual consciousness is exactly not the physical world. What it is, to repeat, is a totality of different things in space and time. It is prior to and a constituent or the like of the physical world.
In short, the fundamental fact of subjectivity is the existence of subjective worlds, no less subjective and no less distinct from the physical world for being spatio-temporal and propertied.
4. The Mind-Body ProblemA fourth constraint on accounts of perceptual consciousness, as of consciousness generally, has to do with the mind-body problem, the problem of the relationship of consciousness to the brain, and, more particularly, of events of consciousness to neural and other physical events. We think of the problem in two ways, (1) in terms of physical events in our environments and also neural events giving rise to or contributing to or being in lawlike or nomic connection with consciousness, and (2) in terms of conscious events giving rise to or contributing to our behaviour, this being physical.11
Accounts of the nature of perceptual consciousness at least have a bearing on the mind-body problem and may actually entail attempts to solve it. To state in one way the constraint on the accounts of the nature of perceptual consciousness, they must at least not worsen the mind-body problem.
To glance back at the first of the four naturalist accounts at the start, eliminative materialism assigns to conscious events only neural properties. In that sense it can be said to identify conscious and neural events. From anything but the perspective of the doctrine itself, of course, what it does is to eliminate conscious events and thereby eliminate the problem of the relationship of such events to physical events. This way with the mind-body problem seems to be another nail in the coffin of eliminative materialism as an account of consciousness, since surely one thing we know of consciousness is that it is such as to raise the mind-body problem.
The second account, event-monism, is to the effect that there is one thing that possesses a first property somehow consistent with what is called physicalism and a second property that is neural. In this event-monism, which is also a property-dualism, a conscious property is related to a neural and physical property by being of the same single thing. The worth of such a view is unsettled. Judgement must wait on adequate accounts of the conscious properties themselves.12 In the absence of these accounts, by the way, there is no real barrier to thinking of the third and fourth naturalistic accounts as instances of this second one, event-monism.
The third account, neural functionalism, regarded as a proposal about the mind-body problem, and of course limited to human minds and bodies, is that a conscious event is a certain causal relatum or effect-cause whose other properties are only neural. It cannot be, as loose talk of realization sometimes suggests, that there are two distinct events in question, a neural one `realizing' the other one. The relationship between the event as neural and the event as conscious, further described, is that the event as conscious is an effect-cause that it might still have been if it were not neural. The fourth account of perceptual consciousness, finally, was that it consists in properties in the head that are physical but not neural -- not part of current neuroscience and not certain to fit into it. They can be regarded as in lawlike connection with known neural properties.
The four accounts, considered in terms of the mind-body problem, share a certain recommendation. It is that the relations into which they put conscious events as they conceive them, on the one hand, and, on the other hand, physical events, are not baffling. More precisely, to come to the fundamental point, causal and other lawlike relations between these two categories of events, which relations indubitably exist, are not left or made baffling.
In the four accounts, these relations hold between (i) neural events (mistakenly supposed by non-materialists to have a distinct property of consciousness) and other neural or otherwise physical events, (ii) events somehow consistent with what is called physicalism and neural or otherwise physical events, (iii) replaceable causal relata and either those same neural events or other neural or otherwise physical events, (iv) physical events yet to be discovered and other physical, perhaps neural, events.
This is of course the strength of naturalism, a matter of the comparison with mental-world or other ethereal accounts of consciousness. These latter accounts, given their vagueness, certainly do not make conscious events into things of which it can be seen that they can be causes or effects of, or in other lawlike connection with, physical events. But the success of the four naturalistic accounts is also their failure. What they do, in the course of making conscious events causally and nomically acceptable, is to divest them of their seeming and actual nature, their reality, and, above all, their subjectivity. Conscious events are, so to speak, left solidly neural or physical, but not solidly conscious.
What of the proposal about the mind-body problem that comes with the account of perceptual consciousness we are considering? It is a proposal, of course, having to do only with perceptual consciousness and what it is causally or nomically related to. The question is that of whether a world of perceptual consciousness can be unbafflingly in causal or other lawlike connection with physical things. We know it has other recommendations, but can it be an unproblematic in this essential way?
To reflect on this is to come to a crucial question. Does an unproblematic cause have to be spatio-temporary and somehow propertied, or does it have to be physical according to the definition with which we have been working? I take it that it is clear only the former is required. To revert to an original crux in the philosophy of mind, the great problem of Descartes' account of the mind was that he put it out of space. The account of perceptual consciousness as existence is certainly different.
I allow that we have an inclination to require our causes and effects to be physical, but what is this requirement? It seems to me that it is an epistemological requirement having to do with certain contemplated or confirmed or true causal statements -- all those having to do with other things than consciousness. What is taken as needed is other and more than a subjective basis. What is needed is a basis having to do with perceivers generally, not just one of them. But that is not a requirement on causal and related connection itself. All that is needed for such connection, really, is something in space and time and somehow propertied.
The final recommendation of taking perceptual consciousness as existence, then, is that it is unique in allowing both for comprehensible causal relations and also for subjectivity, etc. The near-naturalism13 of the account allows for the causal relations, along with them, other things we have to have.
5. Historical Theories, Brains in VatsSo much for an impression of a possible account of perceptual consciousness. Evidently it is different from each of two historical theories of perception, these being analyses of seeing, hearing and so on which give little attention to the matter of consciousness, or indeed by-pass it entirely. One historical theory, direct or `naive' realism, is to the effect that in perception we are aware of only physical objects. The other is the representative theory of perception or phenomenalism, to the effect that what we are aware of is objects internal to the perceiver -- ideas, sense-data, percepts or the like. Certainly they are elusive, true to the ethereal impulse.
The account of perceptual consciousness under consideration has to do with neither physical objects exactly nor of course with ethereal and cranial objects. Rather, it has to do with spatio-temporal and propertied constituents of ordinary physical objects, these constituents being subjective in the fundamental sense that they are not physical objects -- they have a dependency on or are related to one perceiver in particular, etc. If these are important distinctions between the account in hand and the historical theories, there is a yet more fundamental distinction.
It is implicit or explicit in the tradition of direct realism that consciousness or awareness of physical objects consists in a perceiver's baffling relation to them. One thing is clear, however. This relation or fact of perceptual consciousness is not itself taken as being the existence of the physical objects or, more relevantly, the existence of spatio-temporal and propertied constituents of such objects. Rather, the assumption or story is roughly that a chair satisfies conditions of being a physical object, and thereafter it may or may not be perceived by you, within your awareness. Little or nothing is said of this conscious awareness. It is harder to be clear in this connection about the internal objects of awareness in the representative theory of perception. They too, however, seem to be taken as distinct from awareness of them. The fundamental distinction of the account of perceptual consciousness being considered, then, as against the two historical theories, is that for you to be perceptually conscious is for a world or totality of things in a way to exist.
The account is in part similar to direct realism -- in the account, perceptual consciousness is intrinsically made a matter of something not in the head. It will thus be apparent that it is open to something very like the long-running objection to direct realism, this objection also being an argument for a representative theory of perception. The long-running objection and argument is essentially that in perception we cannot be aware of physical objects, since hallucination, where there are no such objects, is indistinguishable from perception. What we must therefore be aware of in both cases is objects internal to ourselves.
The related objection to the account of perceptual experience as existence will be that such experience cannot consist in the existence of propertied things in space and time because something indistinguishable from such experience could be had in the absence of such things. It is conceivable that you, or a brain in a vat, thanks to the ministrations of neuroscientists, could have an experience indistinguishable from one you are having now, but in the absence of the right propertied things in space and time. There are similar objections to other different tendencies in the philosophy of mind to get consciousness out of the cranium.14
In my opinion, the best defence against all such objections, which certainly are troublesome, is an attack on the views being argued for, representative theories of perception. The objections, as must not be forgotten, are commitments to, or at least contemplations of, representative theories. It seems that a certain attack on such views can now have more substance, if not more logic, given our greater knowledge of the processes issuing in consciousness. Also, we may now have a better grasp on the question being answered by representative theories and direct realism, and its distinction as a philosophical question.
At the heart of representative theories of perception is the idea of an inference, from some premise or other to a conclusion about a physical thing. We begin with an internal object of awareness, a sense-datum or the like, and we end up with belief or the like in a chair. But of course there is no sign of any such carry-on in what is called the phenomenology of consciousness. To which truth, of course, it is replied, by defenders of the representative theory, that the inference, and of course also the awareness of the inner thing, are not conscious. That necessary reply must give rise to a fatal rejoinder.
We are now much better informed of the process which issues in your perceptual consciousness of the chair. To actual retinal images we add much about neural structure and activity in the visual cortex, etc. No direct realist and no advocate of perceptual consciousness as existence is committed in the slightest degree to any scepticism about the science, of course. Rather, we draw on it to make what is surely the fatal rejoinder that the representative theory of perception, having taken its subject-matter out of consciousness in order to defend itself, is no more than a kind of impressionistic version of this scientific story or some last part of it.
The scientific story, and the philosophical impression of it, are evidently not an answer to the philosophical question asked, historically or now, about perceptual consciousness. That question, as now seems clear, is the question of the so-called phenomenology of consciousness, better expressed as being of the real nature of consciousness. True to a deep impulse of philosophy, it is a question of at least an epistemological cast, about our conscious acquisition of belief and knowledge. The answer to it cannot be anything like the representative theory of perception, which necessarily removes itself from the discussion. The answer can be the account of perceptual consciousness under consideration. But, whether or not it is, and to stick to the point, the objection from hallucination needs to be regarded for what it is, advocacy of an impossible theory. It is thus not a true objection but a difficulty to be dealt with.
6. Chairs in Minds? Something Left Out?Does the account, whatever can be said for it, nonetheless founder because it puts your perceptual consciousness into space around you, and locates chairs of a kind, not representations of chairs, within your perceptual consciousness? The acount would be more revisionary than it needs to be if it did so, no doubt a disaster for some philosophers. In fact it can be so understood as to respect our resistance to spatializing consciousness in the given way and to putting chairs of a kind within it.
What the account asserts is that for you to be perceptually conscious is for a certain world to exist. For you to fall under a certain description, of being perceptually conscious, it is necessary and enough for something to be the case, that a certain world exists. You do not thereby contain the world. For a thing to be a particular vertex of a particular triangle as a consequence of other properties of the triangle is not for the thing to contain the triangle. For you to be generous is not for your person to contain your gifts to others.15
Still, there certainly is room for a further question. It may be that for a person to be perceptually conscious is for a certain world to exist -- in part, for certain relations to certain things to hold, in particular the several dependency-relations. One term of these relations is said to be a person or the like. But a more precise and satisfactory identification of that item can be asked for, and indeed is owed and needed. It would be another disaster, certainly, somehow to identify the item in question as being conscious, say a conscious subject. To do so would be to fall into useless circularity, to make no analytic advance in the endeavour of trying to explain the nature of perceptual consciousness.
It seems that what needs to be said, the short story, is that for a person to be perceptually conscious is for a certain world to exist which is in part dependent on neural structures and events of the person. Quite a lot is contained in the longer story, as we know, about phenomenology, reality, subjectivity and the mind-body problem, but there is no further and independent fact that needs to be mentioned in order to complete the account of the person's perceptual consciousness.
Are you then inclined to object that this account must go the way of the four naturalistic accounts with which we began? That consciousness is left out? Well, it is essential to keep in mind that a person's perceptual consciousness is indeed being conceived as a subjective world. That is, it is precisely not the physical world, despite its being real in the sense of being spatio-temporal and having propertied things in it. Furthermore, this view of a person's perceptual consciousness takes on strength in a certain way.
The naturalistic accounts, as already implied, give a place to an idea of a subject and an idea of privacy, and, as might be added, they also fit in the idea, in their way, that what is in perceptual consciousness does not also exist unperceived. These contributions give most of us little satisfaction with the naturalistic accounts for a certain reason. Esentially it is that the ideas are applied to a subject-matter, say events with only neural properties, that makes the ideas in question thin and unsustaining. That is, they do little to satisfy another rooted philosophical impulse. The case is different with the account under consideration. Here, so to speak, we have the thing for which the ideas of subjectivity, privacy and so on were made. Here there is something of the right sort to have such properties -- a totality of things.
Do you persist in objecting, nonetheless, that our pre-philosophical conception of consciousness simply is such that one of my so-called worlds of perceptual consciousness could exist, and the person in question not be conscious, not aware of his or her surroundings? That the account under consideration leaves out consciousness? It is my inclination to deny this, or at any rate to see to what extent and with what effect a denial can be sustained. Being perceptually conscious, according to me, is for such a world to exist.
Here are several further reasons. There do exist what are being called worlds of perceptual consciousness. That is, a certain conception is consistent and otherwise conceptually adequate, and things fall under it. If worlds of perceptual consciousness are allowed to exist, but denied to be any part of perceptual consciousness, what is to be said of them? How are we think of them?
Some will say that the idea of a world of perceptual consciousness is a part of what it is to be perceptually conscious. Suppose that much is granted. What could conceivably be the remainder of what it is to be perceptually conscious? Would this be some ethereal stuff, some gossamer, made somehow consistent with a world of perceptual consciousness? Could such a remainder, if ever got clear enough for serious consideration, be other than a peripheral part of the present story?
It is a story which raises still more questions, evidently, but maybe this fertility is no bad thing.
Notes1. For a view of versions of the lenient doctrine, including Donald Davidson's Anomalous Monism and John Searle's two-level identity theory, see my A Theory of Determinism (Oxford University Press, 1988), Chs. 2, 3, or Mind and Brain (Oxford University Press, 1990), Chs. 2, 3. For my account of neural functionalism see `Functionalism, Identity Theories, the Union Theory,' in R. Warner & T. Szubka, eds., The Mind-Body Problem: A Guide to the Current Debate (Blackwell, 1994). The desperate idea that perceptual consciousness consists in non-neural physical properties in the head was floated by me in `Consciousness, Neural Functionalism, Real Subjectivity,' American Philosophical Quarterly, 32, 4, October 1995.
2. Cf. Anthony Quinton, The Nature of Things (Routledge & Kegan Paul, 1973), pp. 46-53.
3. `Consciousness as Existence', in Current Issues in the Philosophy of Mind, Royal Institute of Philosophy Lectures 1996-97, ed. Anthony O'Hear (Cambridge University Press, 1998). For comments on a first draft of the present paper, which is a reworking, development and correction of `Consciousness as Existence,' my thanks to Murali Ramachandran and others at the University of Sussex for an invigorating and good discussion and to Kevin Magill for excellent comments.
4. Cf. the resolute hope in Thomas Nagel's fine `Conceiving the Impossible and the Mind-Body Problem,' Royal Institute of Philosophy Annual Lecture, forthcoming Philosophy, 1998.
5. For an earlier and tradition struggle to catch hold of the subjective aspect of consciousness, see `Seeing Things,' Synthese 98, 1994.
6. Alas I readily conceded otherwise in `Consciousness as Existence,' p. 150.
7. More words to swallow. In `Consciousness as Existence' I said not only that the two chairs are not identical but also, wonderfully, that somehow they are, and also added an identity claim of some sort with respect to the chairs in two worlds of perceptual consciousness. Pp. 151, 152, 154. Identity is impossible, plainly, if only because of different times of existence. Along with the mistaken identity claim went what also cannot be right, that the contents of a world of perceptual consciousness are strictly-speaking physical. Pp. 137, 140, 155. That they are not is a principal recommendation of taking perceptual consciousness as existence -- that subjectivity is really explained.
8. See for example A. J. Ayer, The Central Questions of Philosophy (Weidenfeld & Nicolson, 1973).
9. Nagel, The View From Nowhere (Oxford University Press, 1986)
10. `Consciousness, Neural Functionalism, Real Subjectivity,' American Philosophical Quarterly 32/4, October 1995.
11, What is in a way a separable constraint on an adequate account of perceptual consciousness, as of consciousness generally, is bound up with the fourth one. It is that facts of consciousness itself must be be so understood as to be ineliminable in explanations of our behaviour. Epiphenomenalism is false -- there is mental causation or mental indispensability, truly so named. Perhaps fortunately, there is little call for a proof of this guiding axiom. As with one or two other bits of the philosophy of mind, there seems no proposition more certain than mental causation, and hence nothing available to be a premise in a proof of it.
12. Whatever its conception of consciousness, Davidson's event-monism is in my view open to objection as epiphenomenalist. For his reply, see Mental Causation, ed. John Heil and Alfred Mele (Oxford University Press, 1993).
13. Cf. `Consciousness as Existence,' p. 153.
14. For my different objections to externalism, see `The Union Theory and Anti-Individualism,' Mental Causation, ed. Heil and Mele.
15. Cf. `Consciousness as Existence,' pp. 141, 145, 148.