The Practical and Philosophical Significance of Kant's Universality Formulations of the Categorical Imperative

This article begins with the claim that the Formula of Universal Law, interpreted as a test of the deontic status of actions, can't be made to work. If not, then one might wonder whether what other work it might do in the overall economy of Kant's ethics. I defend what I call the "formal constraint" interpretation of FUL, explaining how it can figure in a defense of the Formula of Humanity, and its psychological significance in moral thinking