The word punishment is used in varying contexts. The punishment meted out by the state to a criminal or by a parent to his children is not the same as the punishment boxers give or receive. The latter, however, is punishment only in a metaphorical sense, for it lacks several of the features necessary to a standard case of punishment. Characteristically, punishment is unpleasant. It is inflicted on an offender because of an offense he has committed; it is deliberately imposed, not just the natural consequence of a person's action (like a hangover), and the unpleasantness is essential to it, not an accidental accompaniment to some other treatment (like the pain of the dentist's drill). It is imposed by an agent authorized by the system of rules against which an offense has been committed; a lynching is not a standard case of punishment. Philosophers who have written on...