An Insanity Debate Goes to the Dogs

This morning I noted the U.S. Supreme Court’s decision in Kahler v. Kansas, upholding a Kansas statute that limits the insanity defense to inability to know what one is doing, omitting the traditional alternative of inability to know that what one is doing is morally wrong. There are many interesting aspects of the debate between Justice Kagan’s opinion for the Court and Justice Breyer’s dissent, but for this post I will focus on just one. The hypothetical that Justice Breyer invokes repeatedly in his argument makes no sense.

Here is Justice Breyer’s hypothetical:

To see why Kansas’ departure is so serious, go back to our two simplified prosecutions: the first of the defendant who,because of serious mental illness, believes the victim is a dog; the second of a defendant who, because of serious mental illness, believes the dog commanded him to kill the victim. Now ask, what moral difference exists between the defendants in the two examples? Assuming equivalently convincing evidence of mental illness, I can find none at all. In both cases, the defendants differ from ordinary persons in ways that would lead most of us to say that they should not be held morally responsible for their acts. I cannot find one defendant more responsible than the other. And for centuries, neither has the law.

Really, Justice Breyer? I see a world of difference.

Defendant Two is delusional, to be sure. He has a mental illness that might qualify under the “product” test now in force in a grand total of one state. But would he qualify under the classic M’Naghten test?

If a killing is otherwise murder (not a justifiable homicide),* the fact that one is ordered to do it by a human is not a defense, even if the human is the leader of one’s country. We established that at Nuremberg. How does a delusional belief that one has been ordered to do it by a dog make a difference? If the fact that the defendant believes were true, the killing would still be murder.

Nothing in Justice Breyer’s hypothetical negates the conclusion that Defendant Two knew that it was wrong to kill the person. As a juror instructed with the M’Naghten test, I would vote to convict Defendant Two.

Historically, in the very long-running debate over the insanity defense, there is frequent discussion of the case of a person with a delusion that he was commanded by God to commit an act. Religious delusions are far more common than canine ones, and they furnish a much stronger argument that the defendant is not morally responsible for his act. Most religious people would believe that a command from God overrides the usual moral rules, but even the most committed dog lover would not believe that Fido has such moral power. So why does Justice Breyer weaken his own argument by reversing the letters in “God” and talking about commands from a dog? I find this very strange.

* Killing is both morally justified and legal in a variety of situations, including self-defense, defense of others, killing the enemy in wartime combat, and execution of a valid sentence of death.