Although punishment has been a crucial feature of every legal system, widespread disagreement exists over the moral principles that can justify its imposition. One fundamental question is why (and whether) the social institution of punishment is warranted. A second question concerns the necessary conditions for punishment in particular cases. A third relates to the degree of severity that is appropriate for particular offenses and offenders. Debates about punishment are important in their own right, but they also raise more general problems about the proper standards for evaluating social practices. The main part of this theoretical overview of the subject of legal punishment concentrates on these issues of justification. That discussion is...