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Book Review - Consciousness, Color, and Content
Consciousness, Color, and Content
by Michael Tye
MIT Press, 2000
Review by Alan N. Sussman
Nov 14th 2002

            The apparent existence of ‘qualia’ seems to make it impossible to describe and explain all psychological phenomena using the standard methods and assumptions of natural science. Anyone hoping for a scientific psychology must somehow either assimilate these qualia into the natural world of particles and fields – and nothing else! -- or show that they do not really exist . Neither alternative seems plausible. Michael Tye’s Consciousness, Color, and Content is entirely devoted to solving this enormously difficult problem of qualia.  

Well, what are qualia? Simply, qualia are those properties of things, or of our experiences of things, that constitute what the world looks and sounds like to us. There is something it is like for us to consciously perceive the world around us; we do not merely – one could say blindly -- record the information we receive. The properties that constitute the quality of our experience, the what-it-is-like-for-us to have the experience, are qualia.  Mailboxes look blue; their blue look is a quale. So is the sound of a trumpet. A fine wine is of no value to one who cannot have the appropriate taste qualia. What a headache feels like is a quale.

To further explain what qualia are, while indicating something of their importance to the non-philosophical readers of this publication, consider the phenomenon of derealization.  In derealization, what the world looks like to someone is oddly changed from normal; the affected individual is not having hallucinations, he sees what is really there, but he sees everything as…somehow – different. This is not to say only that the individual feels differently about what he sees, although he does; rather, what he sees itself appears somehow different to him. I think we have all had at least brief, mild episodes of derealization, especially when in the grip of strong emotion. When we are very anxious, or very depressed, our world looks different: colors are less saturated, borders sharper, volumes more, or less, ‘full’. (I think works of art such as Sartre’s La Nausee or Munch’s Geschrei portray such experiences.) In these cases, it can be said that the perceiver continues to see the real world -- she could still describe it correctly -- but her qualia have changed.

When you put on sunglasses, you may continue to perceive the same world, but your qualia change; the world looks different to you, what it is like for you to look about you has changed. If someone unknowingly grew up with sunglass lenses implanted in  her eyes, the world would presumably look different to her than it does to us,  but her overt behavior would presumably be the same as without the lenses. Indeed, it seems you could have blue qualia whenever I have yellow qualia, so that the qualia you and I have when we are looking at blue and yellow objects are reversed, even though no overt behavior on your part or mine could reveal the fact. Stretching this line of thought, can we not readily conceive of ‘zombies’, creatures that behave exactly as we do, but who have no qualia: they chat and tell jokes, eat and drink, solve crossword puzzles just as we, they even get married and raise children, but they have no qualia, there is nothing it is like for them to be alive, inside they are -- dead. The lesson of zombies seems to be that the existence and nature of qualia is independent of our behavior and bodily states: in principle, either could exist without the other.

We return to the topic of the pathological qualia of derealization. Given the fact that in certain pathological states, the objects we perceive seem to have different perceptible properties, and given that this is an important aspect of the emotional experience, the phenomenon cries out for scientific investigation. Indeed, psychology will provide an incomplete account of our mental life until it can encompass qualia.

But there appear to be serious obstacles to the scientific study of qualia. To see this, recall the zombies mentioned just above. To be a zombie is to be a complete human being who ‘merely’ lacks qualia. But to say that it is possible for there to be a zombie is to say that the rest of what makes us what we are, including our brains, fails to determine what our qualia are. But if this is so, how could we study qualia?  Qualia would be too isolated from everything to be explained by anything.  Recall that first person reports of qualia are not much evidence, since the reports could issue from a zombie, or from someone whose qualia are reversed from ours. This is not the old dualist claim that qualia are not, in fact, products of brain activity, but it is the claim that we could not develop any scientific theory of qualia:  If it is possible for creatures, molecule by molecule, behavior by behavior, identical  to ourselves to lack qualia, then there can be nothing about us or our world that explains qualia.

This sets the stage for Tye’s work. He wishes to naturalize qualia; i.e., he wishes to show that qualia can be studied scientifically as just another part of the natural world, embedded in the causal relations that unify the one physical universe. Tye’s strategy is to identify qualia with the representational features of the associated experience. How things look to us, the ‘phenomenal’ properties of perceptible things, Tye maintains, is nothing but a function of what is being represented by our perceptual experience.  To explain a bit, objects of experience have representational properties in the same way that words and thoughts do. When we speak of green qualia, we are actually referring to how our perception of grass represents the grass, in roughly the same way that the word ‘dog’ represents dogs. One speaks of the ’representational content’ of sentences, of what they say. Just so, the phenomenal properties of perceived objects are the representational content of the perception, what the perception ‘says’ about what is out there. To see qualia in this light is to specify their nature in a way that places them firmly in the natural world: qualia are defined by their function, that function being to represent the world of the one who has them. Being the bearer of such a function is as natural, as accessible to scientific study, as being a voltmeter, something that bears the function of representing the properties of currents.   The entire book is an effort to elaborate and defend this proposal.

A large literature has developed around Tye’s thesis of ‘representationism’, and this book is Tye’s reaction to it. The argument is long and, I venture to say, often ‘tortured’. Some might call it ‘scholastic’. However, if we are to rationally decide to accept or reject the proposal, we must engage in such work.. Nevertheless, I must warn the potential reader that this is very much a book for professional philosophers; and it demands considerable effort and patience.

Time will judge the viability of representationism. If it proves acceptable, it will be important: for one thing, we will be able to use it to scientifically study the pathological qualia of derealization. After all, representation is the central function of the mind.


© 2002 Alan N. Sussman


Alan N. Sussman received his Ph.D. in philosophy from the University of Chicago. He has published a few papers, including one in The Journal of Philosophy. He taught philosophy at various colleges and universities in the US and Africa. At present he teaches part time at Truman College, Chicago. His philosophical interests are primarily in philosophy of mind.