Philosophy of Law Fall 2019

Modern Compatibilism


Morse’s article tries to answer two challenges from neuroscience. The first challenge is that neuroscience seems to show that the brain causes behavior. The second challenge is that neuroscience seems to show that mental states like beliefs, desires, and intentions do not cause behavior. These challenges are both spelled out in the handout.

Morse is especially worried about the second challenge because it threatens to undermine the legal standard for responsibility. The legal standard is rationality: people are liable to punishment only if they are rational. Rationality involves acting on one’s beliefs and desires: rational people act in ways that they believe will enable them to get what they want. If beliefs and desires do not cause actions, then rationality is irrelevant to how we behave and the legal standard of rationality is misconceived.

The law’s compatibilism

The law recognizes excuses for behavior that violates the criminal law. People who do not meet the standards of rationality cannot be punished for their actions.

So what does it mean to be rational? The main component, according to Morse, concerns knowledge: rational people understand what the law requires and the nature of their own behavior (Morse 2010, 842).

Note that this is a pretty low bar. You can behave irrationally, in the sense of doing something that you know to be stupid, and still count as rational as far as the law is concerned. You just have to be capable of understanding what the law requires and what you’re doing.

The law also recognizes external compulsion or coercion as excuses. Those who break the law with a gun to their heads are excused even though they do not suffer from defects in their rationality.

This raises a question about what is sometimes called “internal” compulsion. Cases of internal compulsion involve people who cannot control their behavior. They do what they know to be wrong for reasons that, they maintain, are out of their control. Is internal compulsion an excuse and, if so, why? Morse treats these cases as defects of rationality (Morse 2010, 843). His presentation of his opinion here is quite terse, so I am not entirely confident that I have him right. The idea seems to be that cases of internal compulsion involve an inability to control one’s behavior in the light of what one knows to be right. So you can know what the law is and what your behavior involves but still suffer from a lack of rationality if you can’t bring your knowledge to bear on your actions. The idea is that these cases are similar to cases of external compulsion because it is unusually difficult for the person to make the correct choice. Consequently, the law excuses the behavior in both kinds of case.

In any event, we know that the law excuses people who are subject to external and internal compulsion. The important thing for Morse is that the legal excuse cannot be generalized from these specific causes of behavior to all causes of behavior. So, he maintains, you can be excused if you were forced by a gun to your head but not if your behavior was the product of causal forces that originated with the big bang.

We will talk more about internal compulsion next time, when we discuss the unfortunate Kevin.

The threat to folk psychology

What really worries Morse is the possibility that neuroscience will displace what he calls “folk psychology.” When we employ folk psychology, we explain people’s behavior as the product of their beliefs, desires, and intentions. Morse believes the law assumes folk psychology is accurate and that beliefs, desires, and intentions really do explain why people do the things they do.

Suppose we ask whether someone’s behavior is rational or not. One way of answering that is to see whether it reflects the person’s beliefs and desires or not. Your behavior is rational if it makes sense in the light of what you want to achieve and your beliefs about how to achieve it. If you want to go to lunch and you believe that the cafeteria is to the west of here, your behavior of walking west towards the cafeteria is rational. If you walk south despite believing there is no place to eat to the south, your behavior is irrational.

Here is Morse’s nightmare. If neuroscience displaces folk psychology in the way that the physical sciences have displaced folk physics, one of the assumptions the law relies on would have been shown to be false: the assumption that our behavior can be rational. If your beliefs and desires don’t actually govern your behavior, then the way we assess rationality will be divorced from the behavior we want to evaluate.

The evidence that Morse describes comes from experiments done by Benjamin Libet (Libet 1999). These seem to show that the brain starts acting before the person is consciously aware of having decided to act. That suggests that the intention to act is not the cause of our actions: it happens after the brain takes the first steps to cause an action.1

Meghna said that both Libet and Morse were wrong in assuming that folk psychology requires us to be conscious of our beliefs, desires, and intentions. Meghna says that she rarely thinks consciously about her beliefs and desires before acting. She just picks up a pencil without thinking “I want to write and I believe that picking up the pencil will enable me to write.” But if she does pick up the pencil, that would be a dandy explanation of why she did it: she wanted to write and thought that the pencil was a writing tool.

If Meghna is right, then the electrical activity that Libet’s experiment identified was the intention to move the hand. It’s just that the subjects were not consciously aware of intending to do that for several microseconds. If so, Libet’s experiments do not threaten to displace the folk psychological concepts of belief, desire, and intention. They do displace the the idea that we have to be conscious of our intentions and reasons for actions in order to be rational. But maybe that wasn’t such a good idea in the first place.

A taxonomy of positions on free will

For the record, here is the improved two by two chart. There are two questions each of which has two answers (“yes” and “no”).

  1. Is determinism true? The two answers make up the columns in our chart.

  2. Is it possible that our actions are free and we are responsible for at least some of the things we do even if determinism is true? The answers here are the rows.

Determinism is true Determinism is false
Yes, freedom & responsibility are compatible with determinism Compatibilism (Hobbes, Morse) – (no one)
No, they aren’t (Incompatibilism) Hard Determinism (Greene and Cohen) Libertarianism (Bramhall)

These labels are wonky. “Incompatibilism” is the name of the bottom row but “compatibilism” is only the name of the northwest box. And “hard determinism” is the name for only the southwest box while plain “determinism” refers to the whole western column. But we play the hand we’re dealt. Here is what they mean.

Determinism is the view that everything that happens is causally determined. To put it another way, everything that happens is the effect of a separate cause and causes make their effects happen. This includes human actions.

Compatibilism is the view that our actions can be free, and we can be held responsible for what we do, even if determinism is true. Punishment is a way of holding people responsible for their actions.

Incompatibilism is the view that actions cannot be free, and we cannot be held responsible for what we do, if determinism is true.

Hard determinism combines incompatibilism and determinism.

  1. If determinism is true, actions cannot be free, and we cannot be held responsible for what we do. (Incompatibilist premise)
  2. Determinism is true. (Determinist premise)
  3. Therefore, our actions are not free and we cannot be held responsible for what we do. (Conclusion)

Libertarianism combines incompatibilism with the denial of determinism.

  1. If determinism is true, actions cannot be free, and we cannot be held responsible for what we do. (Incompatibilist premise)
  2. Determinism is not true because some things that happen are not causally determined. In particular, the decisions of the human will are not always causally determined. (Libertarian premise)
  3. Therefore, our actions can be free and we can be held responsible for what we do. (Conclusion)

A taxonomy of theories of punishment

There are two classic positions on punishment.

Consequentialism (aka utilitarianism) is the view that punishment is justified if and only if punishing people promotes the overall good better than any alternative way of dealing with antisocial behavior.

Retributivism is the view that punishment is justified if and only if the person to be punished deserves it. A person deserves to be punished if and only if the person has (a) done something bad and (b) can be held responsible for having done it. (Why two conditions? Because children and insane people do bad things but cannot be held responsible for their actions.)

Remember that the chief problem for the consequentialist view is that it does not require that punishment be used only against those who are guilty, that is, responsible for doing something bad.

How do these positions line up?

Here is what we have.

Positions on free will and punishment
Author Free will view Punishment theory
Bramhall incompatibilist, libertarian retributivist
Hobbes compatibilist consequentialist
Greene & Cohen incompatibilist, hard determinist consequentialist
Morse compatibilist retributivist (probably)

I am calling Morse a retributivist because he is concerned with defending the law as it stands. The law as it stands is not consequentialist: it puts a lot of effort into identifying the guilty and does not engage in any attempt to calculate the consequences of punishment. But I am adding the qualification “probably” because he does not discuss the matter. For all I know, he could be a consequentialist who thinks that the law’s surface retributivism is only sensible as a rule of thumb that produces the best overall consequences in the long run.

Main Points

Here is what you should know or have an opinion about from today’s class.

  1. How Morse answers the charge that the brain causes behavior.
  2. The rationality standard for punishment.
  3. Morse’s worry about the second charge, that “folk psychology” is not true.

Folk physics at work

Morse’s worry is that folk psychology is going to go the way of folk physics, that is, the explanations of physical phenomena that are good enough for everyday life but actually false.

To illustrate folk physics, I asked Jayden to pick up a heavy podium while I held a piece of paper at the same height. Which one will fall faster? We all know it’s the podium. But we’re wrong: they’re going to fall at the same rate. It’s just that the paper is going to be slowed down by air resistance.

Maybe you know that’s the right answer, but I bet you don’t believe it. At least, I bet you’re going to be surprised to see it in action.


Libet, Benjamin. 1999. “Do We Have Free Will?” Journal of Consciousness Studies 6 (8–9): 47–57.
Morse, Stephen J. 2010. “Scientific Challenges to Criminal Responsibility.” In Philosophy of Law, edited by Joel Feinberg, Jules Coleman, and Christopher Kutz, 9th ed., 839–53. Belmont, CA: Wadsworth.

  1. Libet himself has a libertarian view of free will on the grounds that neuroscience has shown that we have an unexplained ability to intervene in the causal chain between the brain’s activating to move the finger and the finger’s actually moving (see Libet 1999, 51–53). I put the Libet article on the sakai site; it’s optional, but people are usually interested.↩︎


There was a handout for this class: 20.Morse.handout.pdf