This paper casts doubt on two objections commonly raised against the "Metaphysics of Morals", namely, its lack of "systematic consistency" when compared with other central works of Kant's critical philosophy and also the apparently misleading admission of legality as a legitimate concept of his practical metaphysical system. It will be argued that the identification of the act of free choice as the supreme concept of the system allows us to face these criticisms firstly by presenting a principle of systematic arrangement which is employed in other admittedly systematic works, and secondly by justifying the central position occupied by the right act, or the action in conformity with duty in Kant's system of morals, which allows for the possibility that both Law and ethical legality be considered as authentic elements of a "Metaphysics of Morals".57134401419