You are just agreeing with the OP here. The point is that prison is useful for some things, eg protecting others, changing behavior etc. But if there is no free

You are just agreeing with the OP here. The point is that prison is useful for some things, eg protecting others, changing behavior etc. But if there is no free will, then it makes no sense to say prison is for vengeance. These discussions are always interestingly recursive, since if I do not believe in free will then my own view on free will is itself not a free choice. And yet I still feel strongly that my not believing in free will appears to be my free choice.