Philosophy of Law Fall 2019

The Case of Kevin


We talked about the case of “Kevin” as presented by Radiolab. Kevin’s behavior changed suddenly after his brain was altered. That seems like good reason to think that it was his brain that was responsible for his crimes rather than him. That is, roughly, an incompatibilist story: if you can blame the brain, you can’t blame the person.

On the other hand, he behaved in ways that suggests he met the standard tests for criminal liability. Compatibilists would be happier with that way of looking at it.

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 what you did 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. If so, you can be responsible for your behavior even if it is caused. All that has to be true is that 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. It is widely used in the US.
  2. Knowledge and control of your behavior in the light of what you know. This is the position of the American Law Institute. This is a proposal to reform the standards used in the US.

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

If we use the American Law Institute standard, as Caroline said, 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. For instance, 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, there is quite a lot of evidence that he had control of his behavior. He didn’t do this at work, for instance.

Berto had a nice way of combining the evidence on this point: he can’t control that he does it even though he can control how or when he does it. That is a very favorable interpretation for Kevin, of course.

This led to a very rich discussion. Here are some, but not all, of the points raised.

Maddie said that he could have asked for help when he was rational. Surely when he got to work and recalled what he had done the night before, he could have thought “something is seriously wrong with me, I should call the doctor.” Or at least he could have drawn a conclusion like this: “I should throw away my computer.”

Caroline said that she thought his case sounded a lot like cases of addiction. The addiction makes you behave irrationally and the shame you feel about your behavior makes you inclined to hide it rather than seeking help. I said that I thought the law could accommodate the irrational behavior part but that it would have trouble excusing the failure to seek hep because of shame. That may be an area where the law should be reformed to better take into account the way human psychology actually works.

I said that I have censorious thoughts about the neurologist who treated him. After the fact, the doctor says that Kevin’s behavior was completely predictable and so should be excused. But why didn’t he tell Kevin that before the fact? Why didn’t he warn him that this was a possibility or ask his wife to monitor his behavior? If Kevin had known there were drugs available to treat him, would he have hidden his behavior?

Ross tried out some ideas from the Speluncean Explorers case. He asked whether the right question is “did he have a choice or was it a matter of necessity from his perspective?”

We ended with some thoughts about the appropriateness of punishment in this case. Maddie said that since drugs eliminate the behavior, there isn’t anything gained by punishing him. Chloe and I said that we thought he appreciated being held responsible, in a way. I think Chloe put it best when she said that being punished reaffirmed that he was still a person.

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.

That said, it was notable to me that few of the people in the story said anything 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 a recent nanny murder case.

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