According to the intuitionist picture of moral normativity, prima facie duties are features of the overall nature of an act, which together make them overall right or wrong. W.D. Ross says that prima facie duties are «not a duty», but something which has a special relation to duty. These fea-tures are «apprehended» by way of an intellectual act (intuition), which implies that they are the object of a theoretical cognitive act. This image creates serious problems for both the theory of moral normativity and the theory of motivation. The problem is how to explain the practical nature of duties and their connection with the will: the intuitionist picture sketches a rather passive role for the will, both in determining the obligatoriness of an action and the possible motivation for it. This rather intellectualistic picture fails to explain the authority and motivational power of moral reasons. Furthermore, the outcome of this position is to lead back to a form of naturalism (an out-come which is certainly contrary to the intuitionist tradition itself) and to a problematic externalist explanation of moral motivation. In the end it is suggested that a more thoroughly Kantian theory of normativity shows a more promising picture for this problem
