The supreme moral law is a practical truth from which every other practical truth can be derived objectively as consequence from its ground

The supreme moral law that Bolzano put in place of Kant’s Categorical Imperative was by no means original. Bolzano, however, modified and justified it in an original way and consistently applied it to many different areas. By the supreme moral law Bolzano means “a practical truth [i.e., a true ought proposition] from which every other practical truth […] can be derived objectively, i.e., as the consequence from its ‘ground’” (RW I, 228; cf. also RW I, 44, 244, 256, RW IV, 27, 217, 221, and WL II