William G. Lycan
University of North Carolina, USA

    My topics are consciousness.  The plural is deliberate.
    Both in philosophy and in psychology, “the problem of consciousness” is supposed to be very special.  And the past fifteen years have seen an explosion of work on “it” by philosophers, psychologists, and neuroscientists as well.  Besides the individual journal articles and books, there is now a vigorous Journal of Consciousness Studies; and John Benjamins Publishing Company’s book series, Advances in Consciousness Research, is flourishing and includes some excellent works.
    But if we look closely at some sample texts, we are struck by an astonishing diversity of topics that have gone under the heading of “consciousness.”

    1.  Here is one sample text.  Martin Davies and Glyn Humphreys begin the Introduction to their acclaimed anthology, Consciousness (1993), as follows.

Consciousness is, perhaps, the aspect of our mental lives that is the most perplexing, for both psychologists and philosophers.  The Macmillan Dictionary of Psychology contains as its entry for consciousness:  ‘the having of perceptions, thoughts, and feelings; awareness.  The term is impossible to define except in terms that are unintelligible without a grasp of what consciousness means’ (Sutherland, 1989, p. 90).  [For whatever reason, Davies and Humphreys chose not to quote the entry’s concluding sentence: ‘Nothing worth reading has been written on it.’]  On the side of philosophy, Daniel Dennett notes in The Oxford Companion to the Mind that consciousness ‘is both the most obvious and the most mysterious feature of our minds’ (Gregory, 1987, p. 160); and Thomas Nagel famously remarks (1974, p. 166), ‘Without consciousness the mind-body problem would be much less interesting.  With consciousness it seems hopeless.’
    These remarks might suggest that consciousness—indefinable and mysterious—falls outside the scope of rational enquiry, defying both scientific and philosophical investigation.  But, in fact, the topic spans the history of psychology from William James until the present; and the past fifteen or twenty years have also seen an upsurge of philosophical interest in the place of consciousness in the natural order.  [p. 1]
    These paragraphs assume, or seem to, that there is this one thing, consciousness (that is elusive and hard to define and perhaps outside the scope of rational enquiry).  The authors later go on to qualify that idea, distinguishing some notions that are so different as to have little to do with each other.  But there are still many readers who would be taken in by those opening paragraphs if they didn’t read further.
    And in fact, the anthologized essays are a grab-bag; some of them bear no discernible relation to others.  The collection contains (besides philosophical articles on the distinct(!) topics of awareness, qualia, and subjectivity), “Theory and Measurement in the Study of Unconscious Processes,” “Impairments of Visual Awareness,” “Freud’s Cognitive Psychology of Intention: The Case of Dora,” and “The Intentionality of Animal Action.”  Brian Smith once said of computation that it “is a site, not a subject-matter”; “consciousness” is a flea market or jumble sale, not even a site.

    2.  By way of complaining about philosophers’ habitual logic-chopping, distinction-mongering, verbal disputation, etc., my psychologist friend Paul Schulman once told me, “We don’t care what anything is called; we just wanna measure it.”  Damned right, too; what does it matter which problems have been called “consciousness”?  Philosophers should not care what the distinct problems are called either.  But everyone ought to care that they are distinct.  Conflation of them is not merely a theoretical possibility.  It has occurred, over and over again, resulting in countless confusions and errors.  I urge us all to keep the distinct problems distinct.  Not only will confusion and error thereby be avoided; I argue that if we divide we shall conquer.
    Some of the topics and issues that have gone under the heading of “consciousness” are brutely empirical.  Some are more abstractly theoretical.  Some are outright philosophical and conceptual.  I myself see these differences as differences of degree only, but they are still differences.  One important difference, though far from the only one, is that of “how does” questions from “how possibly” questions--e.g., “How does a human subject/brain accomplish such-and-such a task?,” vs. “How could any theory of kind so-and-so possibly explain this refractory feature of human experience?” or “How could a mere information-processing system possibly have properties of this remarkable sort?”
    Scientists sometimes pay lip service to one notorious “how possibly” question or another, and even voice that question in a tone of awed respect, but then proceed to announce that what we need is more information-processing models, or more neuroscience, ignoring the theoretical obstacle that drives the “how possibly” question, the obstacle that makes the relevant achievement seem impossible.2
    For example, all too often we hear it suggested that advances in neuroscience will solve Thomas Nagel’s (1974) and Frank Jackson’s (1982) conceptual problem of “knowing what it’s like”—or even that advances in neuroscience have solved it.  This is grievously confused.  For Nagel’s and Jackson’s claim is precisely that there is an irreducible kind of phenomenal knowledge that cannot be revealed by science of any kind.  Nagel’s and Jackson’s respective “Knowledge Arguments” for this radical thesis are purely philosophical; they contain no premises that depend on scientific fact.  Now, either the arguments are unsound or they are sound.  If they are unsound, then so far as has been shown, there is no such irreducible knowledge, and neither science nor anything else is needed to produce it.  But if the arguments are sound, they show that no amount of science could possibly help to produce the special phenomenal knowledge.3   Either way, neither neuroscience nor any other science is pertinent.
    And in general, no appeal to normal science is going to answer any philosopher’s “how possibly” question, though it might happen that some hidden corner of normal science would lessen the force of such a question.

3.  Here are some of the topics and issues that have gone under the “c-” heading.

    So far, these topics are all empirical, or at least toward the empirical end of the spectrum.  Some, like the temporal anomalies, are of more philosophical interest than others.4   But now here are some more abstract and theoretical ones.

    State/event consciousness:  A state of a subject, or an event occurring within the subject, is a conscious as opposed to an unconscious or subconscious state or event  iff the subject is aware of  being in the state / hosting the event.  In virtue of what is the subject aware of some of her/his own mental goings-on but unaware of others?
    Introspection and introspective awareness, and privileged access to the internal character of one's experience itself.  I am directly or “directly” aware of my own experience, or some of it, in a way that you cannot be; that needs explaining.
    Qualia (strictly so called):  The monadic, first-order qualitative features of apparent phenomenal objects.  When you are experiencing a yellowy-orange after-image, what exactly is it that has the yellowy-orange color?  For that matter, when you are (veridically) seeing a ripe banana, there is a corresponding yellow patch in your visual field.  What ontological account is to be given of the yellowness of that patch (which might be as it is even if the banana were not real)?  Bertrand Russell took it to be obvious, in need of no argument at all, that the bearers of such phenomenal color properties are nonphysical individuals, “sense data” as he called them; for impressive argument in addition, see Jackson (1977).
    Homogeneity or grainlessness:  The smooth continuous character of a phenomenal quality such as color, as contrasting with the discrete, particulate nature of the material of which we are made.  The after-image is entirely yellowy-orange, yellowy-orange through and through, without gaps, and it has no part that is not yellowy-orange.  But nothing in the physical world has no part that is not yellowy-orange.  (Sellars, 1962, 1965, 1971.)
    The intrinsic perspectivalness, point-of-view-iness, and/or first-personishness of experience, as discussed by Gunderson (1970), Nagel (1974) and others.  In one way or another, our experience of our own mental states requires the adopting of a very special point of view; our experience of our external environment, though invariably from a point of view, is not perspectival in the same, deeper way.
    Funny facts, or special phenomenal knowledge as allegedly revealed by the “Knowledge Arguments” mentioned above.  It seems that the facts must be nonphysical facts.
    The ineffability of “what it’s like” (in the higher-order sense):  One often cannot express in words what it is like to have a particular sensation.  What is it like to experience the yellowy-orange of a yellowy-orange after-image?  (It’s yellowy-orange, yes, I heard you the first time; but can you tell someone in intrinsic, not comparative, terms, what it’s like to experience visual yellowy-orange?)
    The “explanatory gap” called to our attention by Joseph Levine (1983, 1993):  Even if God were to assure us that, say, the Type-Identity Theory of mind is true and that such-and-such a conscious experience is strictly identical with a firing of certain neural fibers, we would still lack an explanation of why those fiber firings feel to their subjects in the distinctive way they do.  Indeed, to Levine it seems “arbitrary” that they do.

    4.  Psychologists and (especially) philosophers have tended to think of “consciousness” in the same mental breath as “phenomenal experience.”  But notice that phenomenal experience is necessarily involved only in the last six of the foregoing issues, and has nothing intrinsically to do with any of the others.  (I shall call the last six, qualia-strictly-so-called through the explanatory gap, “the problems of phenomenal experience.”)  Just those six are perhaps a daunting array.
    Theories “of consciousness” have been offered by cognitive psychologists (Mandler (1985), Baars (1988), Shallice (1988a, 1988b), Johnson-Laird (1988), Schacter (1989), Kosslyn and Koenig (1992)), and by neuroscientists (Edelman (1989, 1992); Crick and Koch (1990)).  Philosophers have put forward others: D.M. Armstrong’s (1968, 1981) Lockean “inner sense” theory, David Rosenthal’s (1993) Higher-Order Thought theory, D.C. Dennett’s (1991) Multiple Drafts theory.  However, the key thing to grasp about all of these is that not one of them even addresses any of the six problems of phenomenal experience.  I am not speaking pejoratively and I do not mean my previous assertion as a criticism of any of the theories.   Some of their creators did not really aim them at any of the six problems, even though they paid lip service as recorded above.  Others, particularly the philosophers, did not even superficially intend them to address the six problems.  The theories were aimed at different phenomena and may be admirable explanations of those phenomena.
    I draw two morals:  First, no one should claim that problems of phenomenal experience have been solved by any purely cognitive or neuroscientific theory.  (I find myself in surprising agreement with Chalmers (1996) on that.)  Second and perhaps more importantly, the theories cannot fairly be criticized for failing to illuminate problems of phenomenal experience.  And many of them have been so criticized, e.g., by Chalmers (1996).5  Armstrong’s and Rosenthal’s theories, in particular, are very explicitly theories of awareness and of privileged access, not theories of qualia or of subjectivity or of “what it’s like.”  (In fact, both Armstrong and Rosenthal offer theories of qualia, but quite different theories, and elsewhere (Armstrong (1968, 1999), Rosenthal (1991)).  Never criticize a philosophical theory for not explaining X unless the theory is either a theory of X or a theory of something which essentially includes X--at least not when its proponent quite rationally disavows concern for X.

    5.  It is the problems of phenomenal experience that have most greatly exercised philosophers, often under the heading “‘the’ problem of phenomenal experience.”  But even once we have split off the six from the preceding ten and more, we must continue to distinguish and divide.  Much harm has resulted, within philosophy, from conflating among the six themselves.  To make progress, we must take them one at a time.
    For the record--well, not only for it--I will note my own positions on each of the six problems,6  and then conclude with a remark on why the positions are dialectically important.
    Qualia (strictly so called):  I am what has come to be called a Representationalist about the qualitative features of apparent phenomenal objects.  When you see a (real) ripe banana and there is a corresponding yellow patch in your visual field, the yellowness “of” the patch is, like the banana itself, a representatum, an intentional object of the experience.  The experience represents the banana and it represents the yellowness of the banana, and the latter yellowness is all the yellowness that is involved; there is no mental patch that is itself yellow.  If you were only hallucinating a banana, the unreal banana would still be a representatum, but now an intentional inexistent; and so would be its yellowness.  The yellowness would be as it is even though the banana were not real.  Likewise, when you experience a yellowy-orange after-image, you visually represent a colored spot in real physical space, and the yellowy-orange is the represented spot’s represented color.
    Homogeneity or grainlessness:  Here I would appeal to the Representational theory of qualia, and point out that vision does not represent smoothly colored physical objects as having gaps in color.  (It is a further and interesting question whether this is tantamount to vision’s representing the objects as having no gaps in color.)
    The intrinsic perspectivalness, point-of-view-iness, and/or first-personishness of experience:  I defend an “inner sense” theory of awareness and introspection that I swiped from Armstrong (1968, 1981).  On this view, introspection is much like internal perception, and (like any mode of perception) gives you a unique and partial perspective on what you are perceiving.  Indeed, I hold that introspection is the operation of an internal scanner or monitor, that produces representations of your first-order mental states themselves, representations that are made of concepts peculiar to the monitoring device.  The blind men and the elephant are representing the same thing very differently, so differently that they do not, perhaps cannot realize that what they are representing is the same as what each of the other men are representing.  Similarly, seeing an event and hearing the same event may be nothing alike.  And introspecting what is in fact a neural event is not a bit like seeing that same event as from outside one’s head, using mirrors.  Your introspective device deploys very distinctive concepts of its own.  These features of the introspector combine, I hold, to explain the intrinsic perspectivalness of the mental as such:  The mental as such is the neural, not as such, but as viewed from the unique introspective perspective.
    Funny facts and special phenomenal knowledge:  I believe that there is special phenomenal knowledge.  Jackson’s (1982) character Mary the color-blind color scientist knows all the objective, physical facts about color and color perception, but when cured of her malady she herself experiences colors for the first time, and learns a new fact, the fact of what it is (actually) like to see red.  On my view, the sense in which this is a new fact is that fine-grained sense according to which “facts” are not merely chunks of spacetime, but incorporate modes of presentation, or concepts under which the relevant chunks of spacetime are represented: thus, in this sense, that water is splashing and that H2O molecules are moving in such-and-such a way are different “facts,” though in a more obvious coarse-grained sense they are one and the same fact.  In the fine-grained sense, that I weigh 200 pounds and that WGL does are different facts; that the meeting begins at noon and that it begins five minutes from now are different facts; etc.  In none of these cases is there any threat to the materialist view of human beings, but only different perspectives on the same chunk of spacetime.  So too, when Mary learns that it is like… this [however she might classify the experience to herself] to see red, she is representing the qualitative character of the experience from the introspective perspective using an introspective concept, thereby generating a new finely-individuated fact, even though the spacetime chunk she is representing from that highly distinctive point of view is itself scientifically and naturalistically unremarkable.
    The ineffability of “what it’s like”:  Ditto.  When Mary represents the qualitative character of the experience of red, or yellowy-orange, from the introspective perspective she mobilizes an introspective concept, one that is proprietary to her introspector and (for a reason I cannot go into here) does not translate into English or any other natural language.  Of course, the coarse-grained fact that is being reported by her introspector can be expressed and described in many ways, corresponding to many different fine-grained “facts”; it is only the fine-grained fact incorporating the special introspective concept that has no natural-language translation.
    The “explanatory gap”:  I agree that the Gap is real.  But this is for two reasons, neither of which embarrasses materialism.  First, as I have said, phenomenal information and facts of “what it’s like” are ineffable.  But one cannot explain what one cannot express in the first place.  (The existence of ineffable facts is no embarrassment to science or to materialism, so long as they are fine-grained “facts,” incorporating modes of presentation.  It is the modes that make them ineffable, not the underlying coarse-grained fact.)  Second, the Gap is not confined to consciousness in any sense or even to mind; there are many kinds of intrinsically perspectival (fine-grained) facts that cannot be explained.  Pronominal modes of presentation again serve as a good example.  Suppose an opthalmologist explains why WGL is nearsighted.  That does nothing to explain why I am nearsighted; nor could anyone or anything explain that—unless, of course, one first conceded the identity of me with WGL.

    6.  Of course I do not expect anyone (yet) to be convinced of my solutions to the six problems of phenomenal experience, when all I have offered are cryptic summaries of them and without a hint of argument.  (I do hope you will be moved to go out and buy my books, preferably in hardcover.)  But my solutions are solutions, in the sense that if correct they would solve the respective problems.  I believe each one is correct.  I may be wrong in one or more cases or even in all.  But remember that the most difficult problems of phenomenal experience are expressed as “how possibly” questions (“How could a purely physical organism be directly acquainted with qualia?”; “How could materialism permit the existence of intrinsically perspectival, ineffable facts?”).  A “here’s how possibly” answer must be treated with respect unless and until it is refuted.
    Of course, the solutions must be mutually consistent, as (so far as I can see) mine are.  But I hope I have gone some way toward persuading you that each of the problems becomes more tractable once it has been carefully distinguished from the others.


Armstrong, D.M. (1968).  A Materialist Theory of the Mind.  (London: Routledge and Kegan Paul.)
Armstrong, D.M. (1981).  “What is Consciousness?”  In The Nature of Mind.  (Ithaca, NY: Cornell University Press.)
Armstrong, D.M. (1999)  The Mind-Body Problem: An Opinionated Introduction.  (Boulder, CO: Westview Press.)
Baars, B.J. (1988).  A Cognitive Theory of Consciousness.  (Cambridge: Cambridge University Press.)
Baars, B.J. (1995).  “Evidence that Phenomenal Consciousness is the Same as Access Consciousness,” Behavioral and Brain Sciences 18: 249.
Block, N.J. (1993)  Review of D.C. Dennett, Consciousness Explained. Journal of Philosophy 90: 181-93.
Block, N.J. (1995).  “On a Confusion about a Function of Consciousness.” Behavioral and Brain Sciences 18: 227-47.
Chalmers, D. (1996).  The Conscious Mind.  (Oxford: Oxford University Press.)
Crick, F., and C. Koch (1990).  “Towards a Neurobiological Theory of Consciousness.”  Seminars in the Neurosciences 2: 263-75.
Davies, M., and G. Humphreys, eds. (1993).  Consciousness.  (Oxford: Basil Blackwell.)
Dennett, D.C. (1991).  Consciousness Explained.  (Boston: Little, Brown & Co.)
Edelman, G. (1989).  The Remembered Present: A Biological Theory of Consciousness.  (New York: Basic Books.)
Edelman, G. (1992).  Bright Air, Brilliant Fire.  (New York: Basic Books.)
Goldman, A.I. (1993).  “Consciousness, Folk Psychology, and Cognitive Science.”  Consciousness and Cognition 2: 364-82.
Gregory, R.L., ed. (1987).  The Oxford Companion to the Mind.  (Oxford: Oxford University Press.)
Gunderson, K. (1970).  “Asymmetries and Mind-Body Perplexities.”  In M. Radner and S. Winokur (eds.), Minnesota Studies in the Philosophy of Science, Vol. IV.  (Minneapolis: University of Minnesota Press.)
Jackson, F. (1977).  Perception.  (Cambridge: Cambridge University Press.)
Jackson, F. (1982).  “Epiphenomenal Qualia.”  Philosophical Quarterly 32: 127-136.
Johnson-Laird, P. (1988).  “A Computational Analysis of Consciousness.”  In Marcel and Bisiach (1988).
Kosslyn, S., and O. Koenig (1992).  Wet Mind: The New Cognitive Neuroscience.  (Glencoe, IL: Free Press.)
Levine, J. (1983).  “Materialism and Qualia: The Explanatory Gap.” Pacific Philosophical Quarterly 64: 354-61.
Levine, J. (1993).  “On Leaving Out What It’s Like.”  In Davies and Humphreys (1993).
Lycan, W.G. (1987).  Consciousness.  (Cambridge, MA:  Bradford Books / MIT Press.)
Lycan, W.G. (1996).  Consciousness and Experience.  (Cambridge, MA:  Bradford Books / MIT Press.)
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Marcel, A.J., and E. Bisiach (eds.) (1988).  Consciousness in Contemporary Science.  (Oxford: Oxford University Press.)
Nagel, T. (1974).  “What Is It Like to Be a Bat?,” Philosophical Review 83: 435-50.
Rosenthal, D. (1991).  “The Independence of Consciousness and Sensory Quality.”  In E. Villanueva (ed.), Philosophical Issues, I: Consciousness.  (Atascadero, CA: Ridgeview Publishing.)
Rosenthal, D. (1993).  “Thinking that One Thinks.”  In Davies and Humphreys (1993).
Schacter, D.L. (1989).  “On the Relation Between Memory and Consciousness: Dissociable Interactions and Conscious Experience.”  In H. Roediger and F. Craik (eds.), Varieties of Memory and Consciousness: Essays in Honour of Endel Tulving.  (Hillsdale, NJ: Lawrence Erlbaum.)
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Sellars, W. (1965).  “The Identity Approach to the Mind-Body Problem,” Review of Metaphysics 18: 430-51.
Sellars, W. (1971).  “Science, Sense Impressions, and Sensa: A Reply to Cornman,” Review of Metaphysics 24: 391-447.
Shallice, T. (1988a).  From Neuropsychology to Mental Structure.  (Cambridge: Cambridge University Press.)
Shallice, T. (1988b).  “Information-Processing Models of Consciousness: Possibilities and Problems.”  In Marcel and Bisiach (1988).
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1 This talk was originally entitled “Cognitive Theories of Consciousness.”  Thanks to Martin Davies and to Manuel Liz for their excellent comments on it at the ICCS_99 conference.

2 This theme has also been emphasized, and well documented, by Block (1995) and by Chalmers (1996).
Baars (1995) rejoins against Block that “[w]hether consciousness is a ‘mongrel problem’ or purebred is an empirical question” (p. 249).  He gives the example of cancer, which for a time was considered a false natural kind but, he says, is now again regarded as “the same underlying dysfunction, expressed by different pathways and in different tissues” (p. 249).  True or not, this squarely misses the point:  Different senses of “consciousness” may be found empirically to have the same referent, but that would be—just that—an empirical discovery, not something to be simply assumed or even to be established by a priori argument.

3 For the record, I myself believe that the Knowledge Arguments’ conclusion is equivocal.  On one reading, it is entirely unproven and the arguments are simply unsound; on the other, it is proven and true, but not terribly interesting and in particular no threat to materialist theories of mind.  See Lycan (1996), Chs. 3 and 5.

4 For a wonderful discussion of the temporal anomalies, see Chs. 5 and 6 of Dennett (1991).

5 See also Block (1993) and Goldman (1993).

6 Lycan (1987), (1996).  I will not rehearse any of the arguments for the positions, but you may take my word for it that they are decisive.