If we have no free will, then is the entire legal system redundant since no one can be held accountable for anything since no one has control over their own actions?

If no one can legitimately be held accountable for anything, then I think the Anglo-American legal system (the only legal system I know at all well) is worse than redundant (and strictly speaking not even redundant): it's fundamentally corrupt. Indeed, it's hard for me to imagine any legal system that doesn't presume that we have control over at least some of our actions. Even a system that punishes solely for the sake of deterrence or rehabilitation needs to presume that we can control our actions, at least sometimes, in response to examples that are meant to deter us, or as a result of programs that are meant to rehabilitate us.

Your question is a very important one and has been very important historically. It has driven quite a lot of discussion about freewill. Alas, I do not agree with Stephen's answer. If hard determinism is true, which is to say that we have no free will, then, Stephen says, the legal system would be corrupt. So also would be the moral systems, including the one that allows him to use the concept corrupt. Corruption is moral depravity, and if determinism is true and it undercuts law and morals, then there is no such thing as corruption. Those like me who are compatibilists take the view that the truth of determinism would have no consequences for law and morals. The classical compatibilist makes a distinction between those actions that are caused, and those that are coerced, though this distinction is often expressed in different pairs of terms. If an action is caused and subject to scientific law, it is not unfree unless it is also coerced. One would want to include of course psychological self-coercion, which can be distinguished from the normal run of uncoerced actions. Such an action could be punished for reasons of deterrence, but also for retribution or in the interests of abstract justice. For the distinction or one like it between coercion and causation stands, and the justification of retribution for an uncoerced action could still apply, even if that action was determined, provided only that it was not coerced.

Those like me who are compatibilists take the view that the truth of determinism would have no consequences for law and morals.

Like Jonathan, I too am a compatibilist, and I agree with what he says in the italicized statement above. However, the questioner asked about the effect on the legal system of (1) the total absence of free will, not (2) the truth of determinism. I agree with Jonathan that (2) has no consequences for law and morals. But (1) does. One consequence of (1) for morals is that no actions are morally right or wrong. Furthermore, our current legal system routinely assumes that defendants are morally responsible for their actions and able to conform their conduct to standards of right and wrong. If that assumption is false, then our current legal system is corrupt, or at least unfair, assuming that it's unfair to hold people morally responsible when in fact they're not morally responsible. Is hard determinism supposed to imply that nothing is unfair?

If hard determinism is true, which is to say that we have no free will, then, Stephen says, the legal system would be corrupt. So also would be the moral systems, including the one that allows him to use the concept corrupt. Corruption is moral depravity, and if determinism is true and it undercuts law and morals, then there is no such thing as corruption.

Alas, I can't endorse that statement of Jonathan's, according to which hard determinism implies that both (3) moral systems are corrupt and (4) there's no such thing as corruption. If hard determinism is so much as possibly true, then it can't imply both (3) and (4).

Consider two otherwise identical worlds, in one of which determinism is true, and in the other of which it is not. In the second world there is freedom of the will. What difference does this make to the legal system and the moral system? Ex hypothesi, none. When I wrote that if hard determinism is true, moral systems cannot be corrupt, I was describing Stephen's view, not my own! Hence I think the apparent contradiction that he detects. Here's another way of putting the point I wanted to make. We can imagine a deterministic world in which people are thinking good thoughts and doing good things, and making good laws. The world of law and morality seems to have survived the loss of freedom! In this world, some philosophers believe in determinism, and some in freewill. But of course the having of those beliefs is part of a deterministically produced system. There could be incidentally be a deterministic world that is morally and legally better than a world with freewill. Consider the worst world imaginable, but having freewill, and the best world imaginable, but lacking freewill. You might prefer to live in the unpleasant world, but that doesn't mean it's better. In it the innocent are tortured, unfairness abounds, and so on.

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