Most people would be upset if prisoners could go in on Friday, and emerge, rehabilitated, on Sunday.
I for one wouldn't. What do you suppose is wrong with that - besides that it's counterfactual?
(I believe you're misstating Rawls' position on punishment; for instance he says "by enforcing a public system of penalties government removes the grounds for thinking that others are not complying with the rules", which strikes me as a consequentialist argument. I can't recall his arguing in ToJ that "everyone should get the same punishment for the same crime" - I don't even think that can be argued sanely.)
Instead of going to prison, you should be placed somewhere where you can't hurt anybody
Note that in either case your freedom is severely curtailed. The main difference between the two cases seems to be that in one case we classify the condition as a disease, and attempt to treat it; in the other we classify the condition as an aspect of the offender's character, which we believe we shouldn't try to treat (think Clockwork Orange).
You might think this is what we already try to do. But it isn't! Witness this confused article
It is you who are confusing me with this articulation: you are proferring an article (one person's opinion) as supporting evidence for a claim as to what "we" (a vague and nebulous we - is that we humans, we in Western society, we in the US, we the LessWrong community) already try to do. It doesn't seem as if that can possibly work.
One problem with deterrence, as I see it, is that it frequently doesn't work. Putting people in prison doesn't necessarily deter them from crime: it can plausibly make them more likely to commit a crime, because it puts them in contact with a criminal element. In effect, prison trains criminals to become more so.
One root cause of crime seems obvious: socio-economic inequality. Yet instead of passing laws that mitigate inequalities, what we observe in many countries is growing inequality - and predictably no significant abatement of criminal behaviour.
A final point: to a first approximation, no adult ever punishes another. Society has confiscated the authority to punish from citizens and concentrated it into a very small class of specialists. So I'd be suspicious of arguments about what society does that are purely based on evidence about individuals' attitudes toward punishment. What matters isn't everyone's attitude toward punishment; it's how our system for inflicting punishment works, and that may depend little on personal attitudes, in much the same way that personal attitudes toward violence may provide little explanation for how the modern military system works.
One root cause of crime seems obvious: socio-economic inequality.
"Seems obvious" is not an argument. Does someone have links to literature on whether inequality causes crime? On average, are more dollars stolen by rich criminals, or by poor criminals? Is more violence directed by rich people, or by poor people? In Mexico today, the body count in the drug wars, directed by rich people, is greater than all other violence combined.
...What matters isn't everyone's attitude toward punishment; it's how our system for inflicting punishment works
Why do those words go together?
Society - and for once, I'm using this term universally - teaches that, if you committed a crime, you should be punished.
But in some societies, we have an insanity defense. If you had a brain condition so that you had no - here it's a little vague - consciousness, or moral sense, or free will, or, well, something - then it would be cruel to punish you for your crime. Instead of going to prison, you should be placed somewhere where you can't hurt anybody, where professional physicians and counselors can study your case and try to reform you so that you can rejoin society.
Wait - so that isn't what prison is for?
No. Prison is to punish people. Is it any wonder that prison doesn't reform people, when we don't want it to reform them? Most people would be upset if prisoners could go in on Friday, and emerge, rehabilitated, on Sunday. When people say, "It would be cruel to punish people who aren't responsible for their actions", they are implicitly saying, "Prison is necessarily cruel; and that's good, because we should be cruel to criminals who are responsible for their actions."
But the more we learn about psychology and neuroscience, the further responsibility recedes into the distance.
Outcome-based justice argues that we should give up playing the blame game, because neuroscience keeps finding more and more proofs that things are "not our fault". Instead, we should write laws that deter crime.
You might think this is what we already try to do. But it isn't! Witness this confused article from the Brookings Institute, Cognitive Neuroscience and the Future of Punishment by O. Carter Snead. Snead objects to outcome-based justice. He summarized all of the arguments for it, yet managed to completely miss their point, concluding where he started from, saying that outcome-based justice is obviously bad because it could lead to being cruel to people who didn't deserve it. (Instead of only being cruel to the people who do deserve it, which is obviously what we want to do.)
Snead understands that outcome-based justice deters crime:
You might expect that Snead goes on to explain why these laws are bad things. But he doesn't! He assumes we can all see that these are obviously bad things.
The Wrath of Kahneman describes a study which asked whether people punish others in order to deter crime, and concluded, No. People are doing something else.
One theory is that people are trying to be fair. Everyone should get the same chances; everyone should get the same punishment for the same crime. John Rawls argues this explicitly in Justice as Fairness: Justice should not be utilitarian, but should instead be fair.
I believe Rawls' view is also the popular view of what "justice" means. And, I will argue in a later post, it is part of a pattern showing a deep divide between two different ways of using the word "ethics".
ADDED: Constant made the point that, while one part of outcome-based justice is preventing future harm from the criminal on the dock, another part is deterring harm by other criminals. This latter part does not benefit from punishing criminals who cannot be deterred. Thus, to optimally punish both criminals who can and cannot be deterred, the law requires a concept of moral culpability, and should punish criminals who can't be deterred more lightly. This is a better origin story for the linking together of morality and free will than the just-so story I'd come up with, so I plan on stealing it for my next post. (SilasBarta may have been trying to make the same point, but I found his comments impenetrable.)
(This post is laying groundwork for two other posts that will go in different directions, neither of which concerns justice.)