DAVID BROOKS: The Morality Line

Over the next few days, we’ll ponder the sources of Cho Seung-Hui’s rage. There’ll be no shortage of analysts picking apart his hatreds, his feelings of oppression and his dark war against the rich, Christianity and the world at large.

Some will point to the pruning of the brain synapses that may be related to adolescent schizophrenia. Others may point to the possibility that an inability to process serotonin could have led to depression and hyperaggression. Or we could learn that he had been born with a brain injury that made him psychopathic. Or perhaps he was suffering from the ravages of isolation.

It could be, for example, that he grew up with some form of behavioral illness that would have made it hard for him to interact with and respond appropriately to other people. This would have caused others to withdraw from him, leading to a spiral of loneliness that detached him from the world and then caused him to loathe it.

Over the next weeks, we could learn these or other things about Cho Seung-Hui. And as we learn the facts of his life, we’ll be able to fit them into ever more sophisticated models of human behavior. For over the past few decades, neuroscientists, evolutionary psychologists and social scientists have made huge strides in understanding why people — even murderers — do the things they do.

It’s important knowledge, but it’s had the effect of reducing the scope of the human self. “Man is the measure of all things,” the Greek philosopher Protagoras declared millenniums ago. But in the realm of the new science, the individual is like a cork bobbing on the currents of giant forces: evolution, brain chemistry, stress and upbringing. Human consciousness is merely an epiphenomena of the deep and controlling mental processes that lie within.

At the extreme, many scientists now doubt that there is such a thing as free will. As Mark Hallett, a researcher with the National Institute of Neurological Disorders and Stroke, told Dennis Overbye of The Times earlier this year, “Free will does exist, but it’s a perception, not a power or a driving force. People experience free will. They have a sense they are free.” But, he added, “the more you scrutinize it, the more you realize you don’t have it.”

But even in the more mainstream level of the mass media, the scope for individual choice has been reduced, and with it so has the scope for morality. Once, Cho Seung-Hui would have been simply condemned as evil, but now the language of morality is often replaced with the language of determinism. The press this week has been filled with articles like “What Made Him Do It” (Newsweek) or “Why They Kill” (The L.A. Times), which run down the background factors that lead people to become mass murderers.

Responsibility shifts outward from the individual to wider forces. People interviewed on TV tend to direct their anger at the gun, the university administration, society and so on. If they talk about the young killer at all, the socially acceptable word seems to be “troubled.” He’s more acted upon than acting.

In short, the killings at Virginia Tech happen at a moment when we are renegotiating what you might call the Morality Line, the spot where background forces stop and individual choice — and individual responsibility — begins. The killings happen at a moment when the people who explain behavior by talking about biology, chemistry and social science are assertive and on the march, while the people who explain behavior by talking about individual character are confused and losing ground.

And it’s true. We’re never going back. We’re not going to put our knowledge of brain chemistry or evolutionary psychology back in the bottle. It would be madness to think Cho Seung-Hui could have been saved from his demons with better sermons.

But it should be possible to acknowledge the scientists’ insights without allowing them to become monopolists. It should be possible to reconstruct some self-confident explanation for what happened at Virginia Tech that puts individual choice and moral responsibility closer to the center.

After all, according to research by David Buss, 91 percent of men and 84 percent of women have had a vivid homicidal fantasy. But they didn’t act upon it. They don’t turn other people into objects for their own fulfillment.

There still seems to be such things as selves, which are capable of making decisions and controlling destiny. It’s just that these selves can’t be seen on a brain-mapping diagram, and we no longer have any agreement about what they are.