You would probably consider me to your right, but I'm right there with you. Prison should be protective: we lock up people from whom the rest of us will not be safe unless they are segregated. Ideally it is also rehabilitatative, and once (if!) prisoners will be safe and productive members of society there is no point to keeping them locked up.

If there are other methods short of prison that can render law-breakers harmless - such as restrictions on certain activities and occupations - then those should be pursued first.

The ghost of this philosophy, however attenuated, can be seen in systems of pardon and parole.

I acknowledge that a desire for retribution - to punish the evil-doer; make them suffer for what they've done - is a strong impulse (I feel it myself!), deeply imbedded in our tribal psyches, but it should be fought, not indulged.

This seems to me to be the only moral basis for a system of justice and incarceration, though I have no idea how to nudge a society towards this model. Some northern European countries approach it.