Scientific American has a new article, “20 big questions about the future of humanity“, in which twenty well known scientists prognosticate about our collective fate. It’s not clear whether the questions were generated by the scientists themselves or by the magazine, but most of them, and the answers, don’t inspire me much. It’s not that I think the answers are bad, I just think that predictions of this sort—will sex become obsolete? will humans survive the next 500 years? when and where will we find extraterrestrial life?—are shots in the dark, and the answers not that enlightening. After all, the extraterrestrial question is simply a big fat unknown.

But one question and answer, called to my attention by reader John O., intrigued me for obvious reasons. The respondent is the well known philosopher Patricia Churchland. Here’s the question and her answer, and the bold bit in the answer is my own emphasis.

Will brain science change criminal law? “In all likelihood, the brain is a causal machine, in the sense that it goes from state to state as a function of antecedent conditions. The implications of this for criminal law are absolutely nil. For one thing, all mammals and birds have circuitry for self-control, which is modified through reinforcement learning (being rewarded for making good choices), especially in a social context. Criminal law is also about public safety and welfare. Even if we could identify circuitry unique to serial child rapists, for example, they could not just be allowed to go free, because they would be apt to repeat. Were we to conclude, regarding, say, Boston priest John Geoghan, who molested some 130 children, ‘It’s not his fault he has that brain, so let him go home,’ the result would undoubtedly be vigilante justice. And when rough justice takes the place of a criminal justice system rooted in years of making fair-minded law, things get very ugly very quickly.”

—Patricia Churchland, professor of philosophy and neuroscience at the University of California, San Diego

This seems to me both wrongheaded and very superficial, especially when you consider that punishment is part of criminal law. But at least she’s a determinist and a naturalist. We can argue (not this time!) about what this means for conceptions of free will, but I think it’s almost a given that a philosophy involving determinism (either hard determinism or compatibilism) will have implications for criminal law different from those coming from a philosophy of dualism.

That’s certainly the case in practice, for the concept of whether someone could have done otherwise, versus whether he was “compelled” by uncontrollable circumstances in a criminal situation, has played a big role in our judicial system. If you’re considered mentally incompetent, for example, or have a brain tumor that makes you aggressive, or don’t “know right from wrong”, your punishment can vary drastically. If you’re considered mentally ill, you may be hospitalized; if you do know “right from wrong” (even if your circumstances allow you to know it but not act on that knowledge) you will be put in a pretty bad prison situation; and if there are extenuating circumstances that may have influenced your behavior (like an abused woman killing her abuser), your sentence may be light—or you may be even set free.

Under determinism, nobody has a choice of how to act, in other words, there are always “extenuating circumstances” in the form of environmental and genetic factors that caused you to transgress. The way the justice system deals with these factors will, of course, differ from person to person; but it’s vitally important to realize that no criminal had a free choice about what he did. (I’m using “he” here since most criminals are male.) And we can’t deny that lots of punishments are based not on deterrence, rehabilitation, or public safety, but on pure retribution: a vile sentiment that presupposes that someone could have done otherwise.

Even Sean Carroll, a compatibilist, realizes the implications of neuroscience on our justice system. As I quoted him the other day from his new book The Big Picture:

To the extent that neuroscience becomes better and better at predicting what we will do without reference to our personal volition, it will be less and less appropriate to treat people as freely acting agents. Predestination will become part of our real world.

Now I’m not sure I agree with Sean that predicting behavior has anything to do with treating people as “freely acting agents,” for we already know that they’re not freely acting agents. Prediction has to do with your strategy for “punishing” the offender (it affects recidivism and public safety); perhaps that’s what Sean means, but it’s not clear.

Further, Churchland goes badly wrong when she thinks that determinism is solely about understanding why someone does something, and then exculpating them when we do. That’s ludicrous. We need to prevent an offender from reoffending if they’re freed, which means rehabilitation; we need to protect the public even if we do understand why someone commits a crime (what if their neurons make them psychopathic?); and we need to deter others by example from committing crimes. (Deterrence is certainly compatible with determinism: seeing someone get punished affects your brain, often making you less likely to transgress.) I have no idea how Churchland draws a connection between understanding the correlates of behavior and letting people go free, and then—vigilante justice! We already know that “criminal law is about public safety and welfare,” and no determinist thinks otherwise. Determinists are not a group of people hell-bent on freeing criminals!

At any rate, the more we learn about brain function, the more we’ll be able to understand those factors that compel people to behave in a certain way when faced with the appearance of choice. And when we know that, we’ll be better able to treat them. But as we learn more about the brain, my hope is that we will be less and less willing to punish people on the assumption that they made the “wrong choice”, avoid retribution, and begin to design a system of punishment that not only protects society and deters others, but, above all, fixes the problems, both social and neurological, that lead people to break the law.