ABSTRACT
Aside from any “backward-looking” or retributivistic aims we may happen to have, there are at least two things we are typically trying to do when we punish someone for disobeying the law: we are trying to keep them from disobeying the law again, and we are trying to keep others from following their example. In many cases, we may have reason to believe that both of these aims will be served quite effectively by one and the same penalty: the “two-to-five” that we give the mugger for his first offence may arguably be likely both to deter him and to serve as an effective warning to others not to do likewise. In other cases, though, what we think is necessary for effectively deterring potential wrongdoers may be considerably more than what we think is necessary in order to keep the wrongdoer we are punishing from doing wrong again. The most dramatic example of this latter sort of case, of course, is capital punishment. For holding aside complications that are irrelevant to the present point, it seems that the most we would ever have to do to keep a convicted murderer from murdering again would be to imprison him for life. If, however, we had reason to believe that certain potential murderers could be deterred from murdering if we executed those convicted of the relevant sorts of murderers, we might be tempted to resort to execution despite the fact that we are willing to concede that this is not necessary in order to keep the person executed from murdering again.
