The interpretation of the Categorical Imperative presented in the last two chapters shows that Kant’s ethical theory can effectively classify acts under two headings. It can determine whether they are obligatory, merely permissible or forbidden, and whether they are morally worthy, lacking in moral worth or morally unworthy. Kant, it seems, has both a theory of right action and a theory of morally worthy action.

On closer inspection this impression becomes less definite. Are the moral categories which Kant’s theory discriminates in fact those which his labels suggest? Do they correspond to the moral categories distinguished either in common speech or by other theorists? Has he provided decision procedures for either the rightness (i.e. obligatoriness and mere permissibility) or the moral worth of acts in the senses in which we normally use those terms? To answer these questions we must step back from the Kantian texts.

kant and supererogation

The first step back brings into focus Kant’s basic ethical categories and their logical relations. Kant’s account of the basic categories of ethics has recently been challenged by Eisenberg, who contends that Kant’s theory of right and morally worthy action is seriously incomplete because he cannot allow for acts of supererogation, and has to misclassify such acts as fulfilments of duties. I shall consider this charge against Kant’s theory before moving on to the charges often brought that more global defects mar the theory.