“God, freedom and immortality,” these three are traits inseparable from a world in which duty can speak and be obeyed; the Old Testament world is not only _a_ moral world, it is _the only_ moral world. And if, so far, Kant has clung very closely to the Old Testament, we should find him in his later writing--his “Religion within the Domain of Pure Reason”--clinging just as closely to the spirit of the New Testament. Those who find his reasoning obscure and faulty, would explain all this in terms of his personal psychology and his early environment, for Kant was a child of that deep Pietism, one might say Quakerism, that characterizes the Germany of the eighteenth century. But if we look upon him as the child of his age in his devotion to Christianity, he was no less profoundly influenced by that other and equally characteristic movement of his day and generation--the inheritance of Rationalism. The Old Testament and even the New Testament world images may have deep truth hidden in their symbolism--so the child of pietism would be likely to think--but the authority of this truth was not to be sought in revelation. It must be established, if at all, by one’s reason--so the disciple of rationalism was bound to maintain. Now Kant is not only a rationalist, rejecting revelation as a source of authority. He is also a critic, to whom the arguments of rationalism for the existence of God appear flimsy and irrational. Neither in reason nor in experience can we find grounds for accepting the existence of God as a scientific fact. Hume could be no more convinced than Kant that no aspect of the world with which our experience acquaints us justifies a belief in divine purpose. Kant went further--no extension of experience in future ages could give us the assurance we now lack. God is unknown to our science and unknowable. Well then, if neither the necessities of thought nor the facts of experience, however we conceive our knowledge of them extended, can force upon us a belief in God and all that hangs on him, what is left of religion and of morality that cannot be separated from religion? Kant’s answer to this question is so confusing that it is little wonder the interpreters of Kant are confused, in disagreement with each other and each doubtful of himself. I am obliged then, since we have not the time to try out all the ifs and buts of the case, to present dogmatically one line of thought that is to be found in Kant, the one along which post-Kantian thought developed. If anyone tell me that he fails to find this thought in his edition of Kant, or that he finds others that do not run parallel with it, we shall not quarrel about a matter commentators have always quarreled about.