Morse’s article falls into two parts. In the first part, he tries to show that the law’s assumptions about human behavior are compatible with causal determination. Since that is so, identifying causes of criminal behavior at the neurological level should not change anything about the legal standards for criminal liability. In the second part, he tackles neurological experiments that, he believes, genuinely threaten to undermine the law’s assumptions about the conditions under which we can be punished for our behavior.
The law recognizes excuses for behavior that violates the criminal law. People who do not meet the standards of rationality cannot be punished for their actions. For examples of these standards, see the M’Naghten rules.
We discussed two cases in which neurological evidence seems to underwrite these kind of excuses. These are the cases of the man with the tumor and the man who had brain surgery for his epilepsy. In both cases, the damage to the brain seemed to provide a compelling excuse for the behavior.
Morse would be fine with that result. Here, neurological evidence helps to show why the men did not meet the standards of rationality: they could not control their behavior. So far, so good.
The trouble comes when we ask what it means for anyone else to control their behavior assuming that our behavior is caused by our brains and our brains are subject to causal determination like any other physical object.
The one guy could not control his behavior because he had a tumor. But what about a more ordinary criminal whose behavior is also driven by his brain. Why think that guy had any more control over what he did than the tumor guy had?
Like Raphael, I think that Morse would want to say that the tumor victim’s behavior was out of character. That marks the difference. I think I want to say that myself! But I’m not sure that it fully answers the question.
What really worries Morse is the possibility that neuroscience will displace what he calls “folk psychology.” When we employ folk psychology, we explain people’s behavior as the product of their beliefs, desires, and intentions. Morse believes the law assumes folk psychology is accurate and that beliefs, desires, and intentions really do explain why people do the things they do. So if neuroscience displaces folk psychology in the way that the physical sciences have displaced folk physics, one of the assumptions the law relies on would have been shown to be false. That is what Morse worries about.
We spent a fair amount of time talking about the experiments done by Benjamin Libet. These seem to show that the brain starts acting before the person is consciously aware of having decided to act. That suggests that the intention to act is not the cause of our actions: it happens after the brain takes the first steps to cause an action.
We talked very briefly about Libet’s idea that the conscious self can “veto” the brain’s decision to act as well as some of Morse’s criticisms of Libet’s work.
I made a suggestion at the very end (as I tend to do) that they were both wrong in assuming that folk psychology requires us to be conscious of our beliefs, desires, and intentions. I myself rarely explicitly think through exactly what I believe, desire, and intend before acting. But I have no doubt that my actions reflect those things. For example, I do not explicitly think “I would like some coffee now” each morning, much less “and I believe that I will get it if I put the kettle on the stove.” Nonetheless I think that those beliefs and desires explain why I put the kettle on the stove every morning.
What I’m suggesting is that the electrical activity that Libet’s experiment identified was the intention to move the hand. It’s just that the subjects were not consciously aware of intending to do that for several microseconds. If that’s right, Libet’s experiments do not threaten to displace the folk psychological concepts of belief, desire, and intention.