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.
Greene and Cohen argue that we accept this superficially compatibilist condition for incompatibilist reasons. They claim that we think of the reasoning person as a non-physical mind, distinct from the physical brain (the view that mind and brain are distinct entities is called dualism).
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. 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.
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.
To see this, consider some of the things we said. Sydney said that she is reluctant to hold Mr. Puppet responsible because he did not choose the weird life of crime he was destined to follow. Reese added that he had been programmed. As Greene and Cohen see it, the same things can be said of you and me: I didn’t choose my life and my genes and upbringing program me just as much as anything the mad scientist did to Mr. Puppet.
Patrick drew up short at that last point. One difference between me and Mr. Puppet is that there is someone else to blame for Mr. Puppet’s crimes: the mad scientist who programmed him. There is no one else to blame for what I do (once you’re past thirty, you can’t blame your parents any more). I think that is a significant difference between Mr. Puppet and the rest of us and it may well explain why we’re reluctant to excuse Mr. Puppet without doing the same for every criminal (who wasn’t manipulated by a weird scientist). Patrick himself wasn’t sure he wanted to go that far in the end. But you might!
Bogdan wasn’t willing to let Mr. Puppet off the hook. He saw where this was going: if Mr. Puppet isn’t responsible for what he does, then no one is responsible for anything they do. And he wasn’t willing to go there. Michael asked him how he would feel if the scientist could control Mr. Puppet with a joy stick that was connected to a chip in Mr. Puppet’s brain. Bogdan didn’t exactly concede the point, but you see where this is headed. If we’re not going to hold Mr. Puppet-with-a-chip responsible, why is normal programmed Mr. Puppet responsible? And if he isn’t responsible for what he does, why is anyone responsible for what they do?
Both Michael and Patrick were attracted to the idea that neuroscience will not have any significant cultural impact. What it will do, they speculated, is show that what we call “the person” is located in specific parts of the brain. Basically, we will hold those parts of the brain responsible for actions. And we might excuse actions that can be shown to have been caused by other parts of the brain.
What might happen in the future is that neuroscience will lead us to draw distinctions among different parts of even normally functioning brains. We will hold people responsible for actions caused by some parts and we will not hold them responsible for actions caused by other parts. If so, our ideas about responsibility will survive developments in neuroscience, contrary to Greene and Cohen’s prediction that they will fade away.