Abstract
In this paper, I shall discuss the relation between practical reason and emotions in Kant. First, I begin by explaining why knowledge of emotions is important for the transcendental project in the moral domain, understood as the claim that reason can determine our actions, in spite of our inclinations. Second, I explain the definition of affects and passions in Kant's philosophy and relate the two to feelings and the faculty of desire. I then question the possibility of controlling emotions, showing that it is, if not an altogether impossible task, at least a difficult one. I show that while affects present a momentary loss of control, they can still coexist with practical reason. Passions, however, may ground principles for actions, and represent a serious danger for rational mastery over inclinations.