In this paper I shall analyze what Kant says about the different kinds of love, trying to reconstruct what I call a typology of love. I begin with the feeling of sympathy in the Groundwork. Then, I examine the love of benevolence in the Doctrine of Virtue as a duty to love other human beings, which is a duty of virtue toward other people. The introduction of a feeling like love seems, at first sight, strange to the Kantian system, since the moral action should be practiced from duty and not because of sensible inclinations.

I shall show that the duty to love, one that implies the derived duties of beneficence (Wohltätigkeit), gratitude (Dankbarkeit), and sympathy (Teilnehmung), does not reject the purity of moral law. Although the a priori origin of the moral law remains valid, the Metaphysics of Morals deals with the moral applied to rational sensible beings, for which some feelings can be useful in the accomplishment of moral actions, when the respect for the law is not enough. Finally, using the Anthropology, I compare the virtue of love and three other kinds of inclinations: desire, the love-affect, and the love-passion.