concept of the supersensible which (by means of the causality that is thought in it) proves its objective reality in nature by means of the effects it can produce there; and thus renders possible the connexion of both the others with nature, and of all three together with Religion. We have therefore in us a principle capable of determining the Idea of the supersensible within us, and thus also that of the supersensible without us, for knowledge, although only in a practical point of view; a principle this of which mere speculative philosophy (which could give a merely negative concept of freedom) must despair. Consequently the concept of freedom (as fundamental concept of all unconditioned practical laws) can extend Reason beyond those bounds, within which every natural (theoretical) concept must remain hopelessly limited.