The dominant approaches to justifying punishment are retributive (claiming that punishment is justified because people deserve it) and utilitarian (believing that justification lies in the useful purposes that punishment serves). Close analysis of the retributivist position reveals troubling questions about the state's proper purposes and human attempts to equate reward and punishment to moral deserts. Utilitarians generally regard the most important benefits of punishment as general deterrence, norm reinforcement, individual deterrence, incapacitation, reform, and vengeance. During the mid-20th century, U.S. sentencing practices were consonant with utilitarian premises although also consistent with important retributive limits on severity. However, the 1970's reaction against rehabilitation has focused attention on the disparities in the indeterminate sentencing system. Both retributivists and utilitarians share concerns about avoiding convictions of the innocent and not punishing those persons who have the misfortune to be accidental instruments of harm, act in self-defense, or who are insane. The article includes 21 references.