Philosophy of Law Fall 2019

Modern Incompatibilism


Greene and Cohen contend that the law is only superficially compatibilist. The law only requires the capacity for rational behavior as a condition of criminal liability. That is compatible with the causal determination of our actions. You can be rational and have your actions causally determined at the same time. So, on the face of it, nothing that we can learn from neuroscience would directly contradict anything that the law says. That is why the title of their article starts with “For the Law, Neuroscience Changes Nothing.”

However, Greene and Cohen argue, we accept this superficially compatibilist rationality condition for incompatibilist reasons. They claim that we think of the rational person as a non-physical mind, distinct from the physical brain (the view that mind and brain are distinct entities is called dualism). They think we believe that a rational person can be held responsible because we think reason is free from the constraints of physical causation. The brain, by contrast, is subject to causal determination just like every other physical thing.

Neuroscience, according to Greene and Cohen, will undermine this dualist picture of persons by explaining more and more of our behavior as the product of physical causes. As a result, they believe, we will abandon the retributivist parts of our practices of punishment. The retributive ideal is that punishment is reserved for the guilty: those who freely chose to do bad things. Neuroscience, they believe, will show that no one freely chooses anything and so punishment for retributive reasons makes no sense.

In place of retributivism, they believe, we will take up a consequentialist approach to antisocial behavior. They think this is a good thing because they view consequentialism as the more humane approach to punishment. Because they believe that neuroscience will lead us to fundamentally rethink the purposes of the criminal justice system, they end the title of their article with the word “everything,” as in: “For the Law, Neuroscience Changes Nothing and Everything.” So really, in their opinion, neuroscience will change everything.

Mr. Puppet

Greene and Cohen claim to show that we are tacitly incompatibilists with their example of Mr. Puppet. The idea is that Mr. Puppet would not be held responsible for his actions because they were so clearly formed by the scientist. But, they reason, if we aren’t willing to hold Mr. Puppet responsible for behavior that was caused, we should not hold anyone responsible for their behavior. Why? Everyone’s behavior is caused!

We talked about this case for some time. In my opinion, it is the critical part of Greene and Cohen’s argument. We are supposed to think that Mr. Puppet is not responsible and that, in turn, is supposed to show that we are incompatibilists. Without Mr. Puppet, I don’t see that they have another way of showing that people are implicitly incompatibilists.

Our Discussion

Caroline articulated a form of compatibilism. We hold people with standard brains responsible for their behavior and excuse those who have damaged or underdeveloped brains. If she can defend a distinction like that, she can block an argument of the form “if you blame a brain defect rather than the person for a particular crime, then you should blame the brain rather than the person for every crime.”

Concerning Mr. Puppet, we took a straw poll. Four people thought Mr. Puppet is not responsible for his crimes while seven thought he is responsible.

Sarah said that he’s still free to make a choice and that there are good consequentialist reasons for punishing him. If she’s going to be a consequentialist, though, she can drop the question about choice and responsibility.

Sienna also liked a consequentialist justification of punishment but for incompatibilist reasons. That is, she doesn’t think we are responsible for our behavior in the ways that retributivism assumes we are.

Chloe speculated about what we mean by “rationality.” What if it is a name we give to some things that the brain does? If so, perhaps the rationality standard does not depend on dualism.

Caroline noted that the Mr. Puppet case has one feature that normal cases lack: another person who can be blamed! We can blame the scientist for Mr. Puppet’s crimes. In normal cases where criminal behavior is caused by nature and nurture, there isn’t an intelligence manipulating the cases to produce it. That might be a reason why we cannot generalize from the Mr. Puppet case to all criminal behavior.

Main Points

  1. Why the law is at least superficially compatibilist.
  2. Why the law is actually incompatibilist, according to Greene and Cohen.
  3. Why Greene and Cohen think neuroscience will move us towards consequentialism.
  4. The case of Mr. Puppet.


Greene, Joshua, and Jonathan Cohen. 2004. “For the Law, Neuroscience Changes Nothing and Everything.” Philosophical Transactions of the Royal Society 359 (1451): 1775–85.