Kant on duty in the groundwork

Barbara Herman offers an interpretation of Kant's Groundwork on which an action has moral worth if the primary motive for the action is the motive of duty. She offers this approach in place of Richard Henson's sufficiency-based interpretation, according to which an action has moral worth when the motive of duty is sufficient by itself to generate the action. Noa Latham criticizes Herman's account and argues that we cannot make sense of the position that an agent can hold multiple motives for action and yet be motivated by only one of them, concluding that we must accept a face-value interpretation of the Groundwork where morally worthy actions obtain only when the agent's sole motive is the motive of duty. This paper has two goals, one broad and one more constrained. The broader objective is to argue that interpretations of moral worth, as it is presented in the Groundwork, depend on interpretations of Kant's theory of freedom. I show that whether we can make sense of the inclusion of nonmoral motives in morally worthy actions depends on whether the 'always causal framework' is consistent with Kant's theory of freedom. The narrow goal is to show that if we adopt an 'always causal' framework for moral motivation, then Herman's position and her critique of the sufficiency-based approach fail. Furthermore, within this framework I will specify a criterion for judging whether an action is determined by the motive of duty, even in the presence of nonmoral motives. Thus, I argue Latham's conclusion that we must accept a face-value interpretation is incorrect