David Chalmers

talks to Stephen Jones at Tucson II.

SJ: Perhaps you could outline how you come to the idea of the "Hard Problem" and what it means to you?

David Chalmers: I got into this field to try and understand the problem of how a physical system like a brain could also be a conscious being with subjective experience. A lot of people recently have started thinking about consciousness in many different ways - from philosophy, neuroscience, psychology and elsewhere. But when you take a closer look at what people are doing in these fields you find out that they are addressing a number of different questions in the vicinity, not all of which are the deep mystery.

So quite often when you go along to a conference like this Tucson conference, you find out "well, there's a bunch of results on how the brain integrates a bunch of information, for example, and brings it to bear in the control of behaviour", you think "OK well, interesting results" and then you think: "Well, isn't the mystery still there? Why is it that all this processing should give rise to a subjective view of the world? a subjective inner life?" So, in trying to get at this I made a distinction between the easy problems of consciousness and the hard problem.

The easy problems are the kind of problems that neuroscience and psychology can get at sort of straightforwardly. How is it that a brain can discriminate information from the world? How is it that it can bring it together in the brain and integrate it? How is it that the brain or a human being can verbally report their mental states? How is it that we bring information to bear in controlling our action? Now, of course, the easy problems aren't trivial problems. They're going to take a long time to solve, and they'll require a lot of intelligence, creativity and hard work. But we're gradually getting at these questions using the methods of neuroscience and psychology. It's slow work, but there is a clear sense that we have a research program there. We know roughly which direction to move in to get a result.

The trouble is, it seems that even as we work on all these questions, the deep mystery still remains. Despite all the complex brain functioning that we're finding out about, it still remains mysterious. Why is it that all this functioning should give rise to a subjective inner life, an experienced subjective world. I have such a world, I have subjective experience, I presume that you do and that most people do as well. Well, I don't know about others for sure but I'm certain about me. The hard problem is: why is it that physical processing in the brain, no matter how sophisticated, should give rise to any subjective inner life at all, why couldn't that have all gone on in the dark? That's the real mystery.

SJ: So why couldn't this be in some way just the normal functioning of the brain?

DC: There's no question there's an close link between what's going on in the brain and what's happening in conscious experience. They're at least very tightly correlated. I wouldn't resist the claim that the brain somehow gives rise to or produces conscious experience.