The Principle of Deontic Reflexivity and the Kantian Axiom

Some principles of propositional deontic logic present aspects of particular philosophical importance. Two of them are the subject of the present study. The first is the principle of deontic re flexivity (in short the deontic axiom T) according to which if something ought to be then it is. The second one is the Kantian principle (in short OP) according to which `ought-to' entails `can'. Despite their similarities, the two principles are profoundly different both from the formal point of view and as regards their truth value within plausible normative interpretations of deontic logic systems.