Wednesday, January 24, 2007

Probing the soul (a reprise)

More than three centuries ago, Pascal said: "Man considering himself is the great prodigy of nature. For he cannot conceive what his body is, even less what his spirit is, and least of all how body can be united with spirit."

Pascal lived at the dawn of the scientific era, but his words still ring true. We have sent spacecraft to the planets. We have listened to signals from the dawn of time. We have unraveled the mystery of starlight. We can even conceive what the body is. But the deeper human mystery remains: What is the spirit, and how is it united with body?

There is a sense among neuroscientists, psychologists and artificial intelligence researchers that the riddle is ripe for solution. Powerful new imaging technologies make it possible to probe the living brain -- watch the orchestra play, as it were, even as we listen to the music of thought. More powerful generations of computers provide analytical tools to model the complexity of neural circuits. Subtle refinements of molecular biology and chemistry let us fiddle with the machinery of the soul.

A philosopher colleague of mine worries about the experimental manipulation of consciousness. As we learn more about the brain's chemistry, he foresees increasing reliance upon drugs to control our mental lives -- a pill for this, a pill for that. "Increasingly, there's no room for us to talk to one another about our lives," he says. "No room for our histories, our stories, our art; no room for ourselves."

The self has become another object to be investigated, analyzed and manipulated, he says, nothing more than a flickering image on a brain scan monitor as electrochemical activity flares up, dies down, perhaps under chemical control. "Science is squeezing us to spiritual death," he groans, with the deflated spirit of an unreconstructed romantic.

Of course, all knowledge holds potential for abuse. But my colleague's pessimism is unwarranted. As Pascal said, "Man considering himself is the great prodigy of nature." The discovery that our spirits are inextricably linked to electrochemical processes in no way diminishes our true selves. We still have histories, tell stories, make art. We love, we cry, we respond with awe to the marvelous machinery of cognition. And, when necessary, we arm ourselves chemically against the devils of mental illness.

Many of us seem to believe that anything we can understand cannot be worth much, and therefore -- most especially -- we resist the scientific understanding of self. But the ability to know is the measure of our human uniqueness, the thing that distinguishes us from the other animals.

Understanding the machinery of the spirit does not mean that we will ever encompass with our science the rich detail of an individual human life, or the infinitude of ways by which a human brain interacts with the world. Science is a map of the world; it is not the world itself.

We can all agree with the Greek philosopher Heraclitus, who thousands of years ago wrote: "You could not discover the limits of soul, not even if you traveled down every road. Such is the depth of its form."

(This is a revision and extension of a post of several years ago.)