This article is concerned with examining Kant's derivation of the various formulae of his Categorical Imperative. It is in agreement with Paton in maintaining that Kant actually mentions five formulae. But it is not in agreement with him, and some others, in maintaining that they are ultimately reducible to three. Nor is it in agreement with those who maintain that they are ultimately reducible to just one. According to the present article, they are ultimately reducible to two: that about a (...) moral law being a universal law; and that about a moral law involving treating human beings as ends in themselves. (shrink)