Prison is not for punishment. Prison is punishment. The question then is, ‘what purpose does that punishment serve?’
Not vengeance. That is up to God, right? We are dealing with practical goals, not abstractions. This is why I cringe at a statement that a criminal ‘deserves’ a certain punishment. It is not up to us to decide who deserves what, only to find a solution to the problem of the criminal.
The purposes of prison are threefold: One, to keep dangerous individuals away from society for a period of time. Two, to discourage others from doing wrong, and Three, to attempt rehabilitation.
The first of these obviously works. Someone in prison can’t harm society. Life imprisonment is just as effective as a death penalty,* if this is our goal. It might well be argued that some people serving long sentences would be harmless if released and some people serving short sentences should never be released. But we can’t be arbitrary about such things; best to follow rules.
Second, discouragement of crime. That certainly works some. Or so we assume — who knows how much more law-breaking would occur without it? And there are those who will never be discouraged by the threat of imprisonment. They just don’t think their choices through nor realize they don’t have the brains to get away with their crimes.** Thousands of years of punishments have not stopped crimes from being committed. There is no reason to think they will in the future. I’ve know career criminals and many seemed to have difficulty assessing the risk of their actions. It is some impulsive act that tends to get them caught.
And then, rehabilitation. It should certainly be available, even if it will never work for some individuals. People do learn in prison, do come out for the better sometimes. Of course, it would have been nice if they had learned before going to prison. Better late than never, I suppose; education is always a good thing. Some people can not be rehabilitated, I believe. They are simply broken. That is not true of the great majority of lawbreakers.
The ‘punishment’ of prison may always be necessary. Human nature is not likely to change.*** It will never be a solution, in the sense of ending crime, but it does help keep it under control. So, admittedly, would changes in society; that, however, is a different discussion!
*If I were faced with a life in prison sentence and no chance to get out of it, I would almost certainly kill myself. Perhaps we could give the sentenced person that choice.
**It would be obvious that smart criminals evade arrest and conviction more frequently, wouldn’t it? It’s not like the average policeman is particularly brainy (no offense intended to those who serve but you can’t all be Columbo).
***Except maybe by tinkering with our genes.