Tuesday, November 29, 2011

Neuroscientists vs. the Philosophers

An article at Nature News takes up the disparate ways in which neuroscientists and philosophers think about the problem of Free Will.

Neuroscience has shown that prior to a conscious choice the relevant part of the brain shows excitation, as if the brain makes the decision seconds before we are aware of it. Some investigators conclude from this that the brain determines the decision which, say the philosophers, is a bit naive. After all, we would expect that the brain plays some role in the decision-making process, but evidence that it plays a role in the choice is not evidence that it determines the choice.

Even so, if it were to turn out from analyzing brain states that it were possible to completely predict the decision that's ultimately made that would indeed be powerful evidence for determinism. We are, however, very far from being able to do such a thing:
Imagine a situation (philosophers like to do this) in which researchers could always predict what someone would decide from their brain activity, before the subject became aware of their decision. "If that turned out to be true, that would be a threat to free will," says Mele. Still, even those who have perhaps prematurely proclaimed the death of free will agree that such results would have to be replicated on many different levels of decision-making. Pressing a button or playing a game is far removed from making a cup of tea, running for president or committing a crime.
Whatever the case, if libertarian free will is shown to be an illusion, as many scientists believe, the consequences will be severe, but not even these scientists can live consistently with the belief the future is already set and that their choices are already determined.
The practical effects of demolishing free will are hard to predict. Biological determinism doesn't hold up as a defense in law. Legal scholars aren't ready to ditch the principle of personal responsibility. "The law has to be based on the idea that people are responsible for their actions, except in exceptional circumstances," says Nicholas Mackintosh, director of a project on neuroscience and the law run by the Royal Society in London.

Even so, if free will is an illusion, it's one which is very hard to escape, even for those most conscious of its unreality: Haynes's research and its possible implications have certainly had an effect on how he thinks. He remembers being on a plane on his way to a conference and having an epiphany. "Suddenly I had this big vision about the whole deterministic universe, myself, my place in it and all these different points where we believe we're making decisions just reflecting some causal flow." But he couldn't maintain this image of a world without free will for long. "As soon as you start interpreting people's behaviours in your day-to-day life, it's virtually impossible to keep hold of," he says.

Fried, too, finds it impossible to keep determinism at the top of his mind. "I don't think about it every day. I certainly don't think about it when I operate on the human brain."
The whole article is worth reading for anyone interested in the contemporary interface between neuroscience and philosophy. The question of free will is not simply an ivory tower exercise. There are a number of consequences which follow if it turns out that determinism is true, none of them good.

If it is the case that our choices are determined by extrinsic causes like environment or our genes then there can be no such thing as a moral obligation since we can only be obligated to do what's possible to do. Nor would reward and punishment ever be deserved since no one is ultimately responsible for their choices. The categories of good and evil would cease to be meaningful as moral categories since without moral obligation there really is no morality. Human dignity, which is based on an ability to choose our path, would be difficult to maintain and for those who are theists it would be hard to avoid the conclusion that the pain and suffering in the world is ultimately authored by God.

Any one of these consequences would by itself be disastrous for civilization. Let's hope that those neuroscientists intent on proving that they don't really have the freedom to choose to believe their theories or to reject them, but are determined by factors beyond their control to believe whatever they believe, come to discover that that notion makes not only their science but all of life incoherent. It's no wonder that they can't live consistently with it.