Putting together Kant's theory of emotion is complicated by two facts: (1) Kant has no term which is an obvious equivalent of "emotion" as used in contemporary English; (2) theorists disagree about what emotions are. These obstacles notwithstanding, my dissertation aims to provide the foundation for a reconstruction of Kant's theory of emotion that is both historically accurate and responsive to contemporary philosophical concerns. In contrast to available approaches which rest on contested assumptions about emotions, I start from the generally accepted and reasonable premise that what we call "emotions" refers in Kant to a set of mental states, some of which he associates with the feeling of pleasure and displeasure ("feelings"), others with the faculty of desire ("desires"). I then proceed to examine the nature of these two kinds of mental states and their proper treatment. I argue that Kantian feelings are representations of objects' relation to the subject, that have a felt quality, and dispose their subject to certain behaviors. While feelings can only motivate action by causing desires and have no temporal direction, desires - except for certain wishes - are future-directed, which allows them to motivate actions immediately (but they need not bring action about). Equipped with this account of feelings and desires, I proceed to examine the kind of treatment Kant prescribes for them, and argue that feelings (except affects) should be cultivated, that is, acquired and improved so that they could be used to pursue rational ends, while inclinations, i.e., habitual sensuous desires, should generally be disciplined, that is, constrained by rules. The resultant picture is compelling because it rests on minimal assumptions about emotions and successfully incorporates the phenomenological, evaluative, and dispositional functions traditionally associated with emotions.