[From the name of the German philosopher Immanuel Kant (1724-1804).]
(system) Although Immanuel Kant is known for transcendentalism or idealism in metaphysics and a subtle constructivism in epistemology, his signature idea was deontologism in ethics. In particular, Kant's fundamental contribution to ethical thought was the categorical imperative, according to which the only actions we can legitimately call moral are those that are done purely for the sake of a universal moral law, not from any personal interest (not even an interest in acting ethically!).