A redated post. This seems to have gotten some discussion just today. Also, see this essay by a Brandeis University sophomore (!) which brings the discussion of Lewis on punishment up to date.
This is the famous essay in which Lewis defends a retributive theory of criminal punishment. Should criminal punishment be retributive?
I am redating this post once again to show how, in present-day secular thinking, the idea of what a person deserves has a tendency to drop out. This is something that has to be sorted out when we talk about moral responsibility. Remember, Lewis wrote the essay because he thought the idea of punishment based on desert was in danger of being lost.