Should society attempt to restore law violators to the community, or should violators merely be punished for their misdeeds?
The justifications for imprisonment falls into four categories. First, it is a punishment. (Whether fear of that punishment in itself will prevent some crime is debatable.) Second, it is a preventative, in that the violator cannot commit any more crimes while imprisoned; this is particularly relevant in cases involving drug, alcohol, and/or sexual addiction. Third, it is considered a relief or closure for the victim of the crime; often in parole hearings the main opposing voice is that of the still suffering or angry victim, who thinks that the prisoner has not suffered enough yet. Lastly, imprisonment is seen as an opportunity for rehabilitation, by tangible programs such as AA, education classes, and peer counseling, and psychologically, by self-examination and personal repentance.
Of these possibilities, common sense tells us that restoring a wrong-doer to a productive place in society would be the most valuable result, but the stigma of having been in prison prevents much re-absorbing into society, because the average citizen thinks only that the psychological/ethical/moral conditions that prevailed for the first offense are still present in the offender – once a theft is exposed, the offender will always be a thief, not to be trusted in any business venture. (A very recent development here is to omit the box marked "Do you have a prison record?" on job applications.)
The main sociological problem with incarceration is that there is little or no room in the system for individualization – the prisoners are given numbers, the uniforms and rules for dress are strictly enforced, the diets are uniform, the ability to maintain one’s individuality is circumscribed by both the limiting of objects allowed (no paints, brushes, etc.) and by the automatic condensation into a gang or group of “like” prisoners. As a consequence, individual prisoners cannot be treated differently, depending on their motives, personal characteristics, etc. (The whole story of Les Miserables winds around this flaw in the Justice system.)
Society has never clearly stated the function of incarceration, except that it is the only “accepted” form of punishment -- no “cruel or unusual punishment” is allowed, according to the Constitution. If some lawmaker would spell out the need for rehabilitation as part of one’s punishment, much good would come of restoring law violators to the community. So from the standpoint of Society’s best interests, rehabilitation is by far the noblest and most humane motive. But unfortunately, human nature (the desire for revenge, fear of harm, and illusions of moral superiority) prevents much positive growth in this direction.