 Kant, on the other hand, seemed to have understood the categorical imperative as a kind of action-guiding standard. Kant’s discussion of examples in the Groundwork (1785) and his characterization of the Formula of Universal Law as appropriate method for testing our maxims makes clear that he thinks of it as appropriately guiding the actions of the morally virtuous agent. Equally clearly, the categorical imperative is to be understood as the most fundamental explanation of why given actions are right or wrong, and so also counts as a principle qua standard. On a constitutivist reading, the categorical imperative is meant to play both of these roles in virtue of its constituting our rational agency. Finally, it is worth noting in this context that a principle can function usefully as a guide even if its application requires judgment and sensitivity; principles qua guides need not be algorithmic.