Philosophy of Law Spring 2018

The Case of Kevin


We talked about the case of “Kevin” as presented by Radiolab.

Necessary conditions on responsibility

What are the necessary conditions for being responsible for your actions, where “being responsible” means that you could be justifiably punished for what you did?

Incompatibilists say the necessary condition is that you are the cause of your behavior, free from any other causes outside of your control.

The law, as described by Morse, maintains that the necessary condition is rationality: you can be responsible for your behavior only if you were rational when you did it. In this way, the law is compatibilist: it holds that rationality is the only necessary condition for being responsible for your behavior. So even if your behavior is caused, you can be responsible for it so long as you were rational when you did it.

We started off today’s class with two more detailed statements of what rationality involves. These come from attempts to devise criteria for determining when insanity is an appropriate defense against a criminal charge.

  1. Knowledge of (a) right and wrong and (b) what you are doing. This is the M’Naghten Rule.
  2. Knowledge and control of your behavior in the light of what you know. This is the position of the American Law Institute.

If we use the M’Naghten Rule, Kevin is pretty clearly responsible. He wasn’t deluded.

If we use the American Law Institute standard, it’s at least debatable whether he is responsible or not.

On the one hand, there is a lot of evidence that his behavior was something that he could not control. As Sophia pointed out, he was engaging in binge eating. And he was in these strange cycles of downloading files, deleting them, then downloading them again; that suggests at the very least a serious struggle for control between the different parts of his mind.

On the other hand, as Niyati noted, there is evidence that he had impulse control. He didn’t do this at work, for instance. And, as Will observed, he could have sought help.

These are just the starting points of a very rich discussion. Among other things, we touched on the responsibility of his doctors to monitor him, given that they later claimed his behavior was completely expected. That is a point I had not considered before.

Above all, Meera’s question is the right one: what do we mean by “control”?

The big picture

If we’re going to say that Kevin should not be punished because his brain was responsible rather than him, then we are on the road to saying that no one can be punished. After all, everyone’s brain is responsible for their behavior. At least, that’s what materialistic neuroscience seems to be on the road to showing … someday.

It was notable to me that few of the people in the story said something like that. Kevin, his wife, the judge, and the prosecutor all applied the compatibilist standards of rationality. They were primarily interested in whether he was capable of controlling his behavior in the light of his knowledge of right and wrong, which is the American Law Institute standard for rationality.

Everyone agrees on the facts of the case. What is at issue is how we understand or interpret them. That is where philosophy comes in. If we interpret the story of Kevin as showing that punishment is inappropriate because his actions were caused by his brain, we are headed towards incompatibilism. If we interpret the story as showing that the law’s normal standards for assessing rationality and insanity can be applied to a case like this, then we are taking up a compatibilist position.

Key concepts

  1. The facts of Kevin’s case
  2. The difference between the M’Naghten Rule and the American Law Institute’s rules
  3. Do you interpret Kevin’s case in an incompatibilist way or a compatibilist one? That is, do you think he should not be blamed because his brain injuries are responsible for his behavior or do you think the law’s normal standards can be appropriately applied to his case?


Oliver Sacks wrote up a description of what appears to be the same case, just in case you would like to read more.

Some of the difficulties with the insanity defense are raised by the recent nanny murder case.

And if you would like to see someone undergoing brain surgery while playing the flute, we have you covered.