Kant's moral philosophy intends to be an articulated project between metaphysics of morals and practical anthropology. In the works in which he undertakes the task of grounding his metaphysics of morals, namely, The Groundwork of the Metaphysics of Morals and the Critique of Practical Reason, Kant insists that he borrows nothing from anthropology to support this grounding, whereas in his two other most important practical writings, the Religion Within the Boundaries of Mere Reason and the Metaphysics of Morals, Kant applies his metaphysics of morals to anthropology. By discussing Kant's idea that empirical happiness is an essential end for every human being, and that his metaphysics of morals is just incoherent without denying rationality and freedom to every sensible incentive, this paper problematizes the possibility of the articulated project of Kant's moral philosophy. [ABSTRACT FROM AUTHOR]