Abstract
A moral code consists of principles that assign moral status to individual actions – principles that evaluate acts as right or wrong, prohibited or obligatory, permissible or supererogatory. Many theorists have held that such principles must serve two distinct functions. On the one hand, they serve a theoretical function, insofar as they specify the characteristics in virtue of which acts possess their moral status. On the other hand, they serve a practical function, insofar as they provide an action-guide: a standard by reference to which a person can choose which acts to perform and which not. Although the theoretical and practical functions of moral principles are closely linked, it is not at all obvious that what enables a principle to fill one of these roles automatically equips it to fill the other. In this paper I shall briefly examine some of the reasons why a moral principle might fail to fill its practical role, i.e., be incapable of guiding decisions. I shall then sketch three common responses to this kind of failure, and examine in some detail the adequacy of one of the most popular of these responses