Thursday, January 25, 2007

The Mystery of Consciousness

Steven Pinker has written an interesting, if rather lengthy, essay on the nature of consciousness and the problems researchers in the field are seeking to solve. Pinker is a substance monist, a materialist, who believes that consciousness is explicable purely in terms of brain function. I think he's probably wrong about that but his article is worth reading for the insight it gives into the controversy. Here are a few early paragraphs:

What remains is not one problem about consciousness but two, which the philosopher David Chalmers has dubbed the Easy Problem and the Hard Problem. Calling the first one easy is an in-joke: it is easy in the sense that curing cancer or sending someone to Mars is easy. That is, scientists more or less know what to look for, and with enough brainpower and funding, they would probably crack it in this century.

What exactly is the Easy Problem? It's the one that Freud made famous, the difference between conscious and unconscious thoughts. Some kinds of information in the brain--such as the surfaces in front of you, your daydreams, your plans for the day, your pleasures and peeves--are conscious. You can ponder them, discuss them and let them guide your behavior. Other kinds, like the control of your heart rate, the rules that order the words as you speak and the sequence of muscle contractions that allow you to hold a pencil, are unconscious. They must be in the brain somewhere because you couldn't walk and talk and see without them, but they are sealed off from your planning and reasoning circuits, and you can't say a thing about them.

The Easy Problem, then, is to distinguish conscious from unconscious mental computation, identify its correlates in the brain and explain why it evolved.

The Hard Problem, on the other hand, is why it feels like something to have a conscious process going on in one's head--why there is first-person, subjective experience. Not only does a green thing look different from a red thing, remind us of other green things and inspire us to say, "That's green" (the Easy Problem), but it also actually looks green: it produces an experience of sheer greenness that isn't reducible to anything else. As Louis Armstrong said in response to a request to define jazz, "When you got to ask what it is, you never get to know."

The Hard Problem is explaining how subjective experience arises from neural computation. The problem is hard because no one knows what a solution might look like or even whether it is a genuine scientific problem in the first place. And not surprisingly, everyone agrees that the hard problem (if it is a problem) remains a mystery.

Toward the end he lays his materialist cards on the table:

Whatever the solutions to the Easy and Hard problems turn out to be, few scientists doubt that they will locate consciousness in the activity of the brain. For many nonscientists, this is a terrifying prospect. Not only does it strangle the hope that we might survive the death of our bodies, but it also seems to undermine the notion that we are free agents responsible for our choices--not just in this lifetime but also in a life to come. In his millennial essay "Sorry, but Your Soul Just Died," Tom Wolfe worried that when science has killed the soul, "the lurid carnival that will ensue may make the phrase 'the total eclipse of all values' seem tame."

Having written six pages he apparently gets a little giddy, and allows himself to make the ludicrous suggestion that recognizing that other people have brains like ours makes for a better basis for morality than does belief in eternal life.

We'll have more to say about the last page of Pinker's article tomorrow.

RLC