What is Consciousness? | Daniel C. Dennett

Dan, you've been thinking about consciousness professionally for getting near half a century now. What have you learned during this period? I've learned first that some of my initial ideas, I think, were right on target, but they're a lot more complicated and a lot more interesting than I thought when I wrote my first work on consciousness. So the core idea is that... The core idea is that consciousness is not a mysterious property or phenomenon that sunders the universe in twain. It's a complicated variety of different things, and the model that we use, which is our own consciousness, which we understand from all the ways we interact and talk with each other about it, when we apply that to other creatures and robots and the like, we get in a lot of trouble because some of the features of our consciousness are just not features of the consciousness of other creatures. So should we call what they have consciousness? Well, that's a terminological dispute that is not worth answering. Let's get the features down, and once we've got a good theory of all the different varieties, then we can decide who owns the terms. Okay, so if that's the core, then what are some of these features that have enriched your understanding over these years? I think the most important change that I made from my earliest work was the recognition that what's happening in the brain is there are many competing streams of content running in competition, and they're fighting for influence or fame in the brain, and the one that temporarily wins, it's king of the mountain, that's what we can remember, what we can talk about, what we can report, and what plays a dominant role in guiding our behavior. Those are the contents of consciousness, but they're not distinguished from all the others by being transduced into some other medium. There's no place where it all comes together. There's just this competition for influence going on in the brain. Now, that to me sounds like attention as opposed to this subjective quality or the sense that there's this inner movie that we experience. Well, attention is very much at the heart of it, and rightly so, but attention can be diffuse or it can be very focused, and that in itself, it's not just like a spotlight with things in it and things that are out of it, and some things that are not focused on, not attended, can nevertheless play big roles in modulating our behavior. But what's missing, you're saying, is the subjective feel or something, the qualia. Yeah, and one can imagine you can have attention in a system, a biological system, without having the qualia. Well, what do you mean by the qualia? I think the idea of qualia is in the end broken back. We should just get rid of it. It means too many different things to too many different people. It's a philosophical term of art which has never been well-defined. The trouble is that for many people, qualia are, if you like, by definition, intrinsic, non-functional features of consciousness. Well, that just by definition rules out any functionalistic decomposition of them. But in fact, you can do that, and there are some lovely examples now. I particularly admire David Huron's work in his wonderful book, Sweet Anticipation. It's a book about music. He's a musicologist neuroscientist, and he takes the qualia of the scale tones, Do, Re, Mi, Fa, Sol, La, Ti, Do, and he asks dozens of people, including trained musicians, just to pre-associate on what the qualia are that they associate with Do, with Re, with Ti. And he writes down all the adjectives and metaphors that they come up with. Then he does a careful statistical analysis of them and finds that they cluster and finds that he has a theory that explains how these are implemented in the brain. He's got a decomposition analysis of the intrinsic ineffable qualia of the scale tones. Well, if you can do that for scale tones, I mean, I think we do. Musicians, in particular, will tell you that Mi and Sol are really different. And no matter what key you're playing in, they're different. And they say the difference is ineffable. Well, it's not ineffable. If you do the science, you can take those qualia apart. Now, it's important to realize that when you do that, it's not the case that these neural features conspire to produce shazam, this extra thing, the qualia. No, it's that these neural features produce the reactions that go with Mi or Sol or Ti and the beliefs and the expectations and the distastes or the loves. All of these emotional affective reactions are engendered by these complex neural combinations that he's taken apart. When we've got that done, there's no room. The qualia themselves, there's no work for them to do. Is that an identity theory that says those complex neural relationships and fire rings all together? Is that feeling, is it an exact identity theory? Well, the trouble with the term identity theory is that you don't have a good identity theory unless you've got crisp, clean characterizations of the things to the left and the right of the equal sign. The trouble is that the thing on the left side, the qualia, don't have a good, clear definition. So no matter what I put on the right-hand side, there's always going to be somebody who's got a different conception of qualia and say, well, I've got a counterexample to that given my understanding of qualia. Well, of course you do. So what? Maybe your concept of qualia is just not a good one and there's a better one which does justice to the phenomena. So I think this is one case where the philosophers, not just penchant but need for definitions, stands in the way of getting clear. People end up spending all their time and energy hammering away on the definitions and the counterexamples instead of looking at the empirical work that you might do. That's profoundly subversive as a philosopher for me to say that, but that's what I've come to appreciate more and more over the years.