Sunday, December 03, 2006

Consciousness: John Searle confronts the problem of understanding what consciousness is ...

After decades of neglect, the topic of the nature of consciousness has become "fashionable" again. John Searle notes in "Minding the Brain" in the New York Review of Books (November 2, 2006), that
After having been neglected for most of the twentieth century, the subject of consciousness has become fashionable. Amazon lists 3,865 books under 'consciousness,' a number of them new releases of the last year or two. What exactly is the problem of consciousness, and why exactly is it so difficult, if not impossible, for us to agree on a solution to it? Of course, there is more than one problem, and there are many different reasons for disagreeing with proposed solutions.

The hard problem of consciousness is to account for how it can exist and function in a way that is private, subjective, and qualitative, in a world that consists of public, objective, physical phenomena. How, for example, could the electrochemical activities of a kilogram and a half, about three pounds, of matter in my skull cause all of my conscious experiences? The problem of consciousness is the heart of the traditional 'mind-body problem' in philosophy. What is the relation of the conscious mind to the physical brain and the rest of the body?

Searle, reviewing Nicholas Humphrey's recent book Seeing Red: A Study in Consciousness on, among other things, blindsight, makes refreshingly clear how hard the problem is because the best definition of consciousnesss that he can think of is, "By "consciousness," I mean those states of sentience or feeling or awareness that begin when you wake up from a dreamless sleep and continue on throughout the day until you fall asleep again, or otherwise become unconscious. Dreams are also a form of consciousness."

Now, I think that is actually quite a useful definition, because we all know what state we are referring to when we talk about a conscious state. But it doesn't tell you what consciousness is, only approximately when you are likely to experience it.

And if you were not the sort of being who was ever going to be conscious, well, you wouldn't even be reading his definition. So it works. But the fact that this is what works beautifully illustrates the hard problem of consciousness.

But then he says, "Consciousness is entirely caused by brain processes. We don't know many of the details of these processes, although neurobiologists are making much progress in tracing them. But there isn't any real doubt that processes in our brains are causing our conscious experiences." How do we know that processes in our brains are causing our conscious experiences, as opposed to making it possible for them to be experiences about this world? If we assume, with most traditional philosophies and religions, that the human spirit is immortal, that is precisely what we should expect. Our living brain makes possible our consciousness of experiences in this world, in the same way that knowledge of a language makes possible the experience of living and working in that language.

Burt he says some really interesting things about the problem, for example,
We know from high school physics that in presenting an equation you have to be referring to the same dimension on both of its sides. The equation one dollar = one hundred cents can work because both sides are sums of money. But you couldn't have one hundred cents = one month, because cents and months are in different dimensions. Mind and brain appear to be in different dimensions, because mind has qualitative subjectivity and brain does not. If you try to say, for example, that the experience of red is identical with neuron firings, the terms of the equation seem to be in different dimensions, because the conscious experience of red has the qualitative sub-jectivity that I described earlier, while neuron firings do not.

Remember this when someone tells you that consciousness is an illusion or there is no real problem with explaining consciousness or whatever.

Humphrey, whose book Searle is reviewing, is handicapped by a need to give an "evolutionary" account of the origin of consciousness. Given that consciousness can only be described with reference to what we all know it feels like, he is probably only compounding his difficulties in this way. But you cannot be a card-carrying materialist without attempting a materialist explanation, and Searle is uncertain what to make of all that: "... some evolutionary story about consciousness must be right. But whatever evolutionary story may be proposed is an answer to a different question from the causal question." Yes, and we don't even know that some evolutionary story has got to be right either. Consciousness might have been a very rapid development, somewhat like the sudden insights that lead to great discoveries. The trouble is, we do not know what we do not know.

My other blog is the Post-Darwinist, which keeps tabs on the intelligent design controversy.

Forthcoming book: The Spiritual Brain (Harper 2007) by Mario Beauregard and Denyse O'Leary

Labels: ,