I say that Kant is prepared to prove that without these three assumptions, God, freedom and immortality, no categorical imperative is possible; but I am far from asserting that a conscientious thinker will be prepared to follow Kant in every step of this proof. It is in most parts a tortured process of reasoning at once over subtle and over simple, and back of it all, one feels that Kant’s deepest motives for arriving at his conclusions are the instinctive demands of his heart, which demands a marvelous intellect is made to serve as best it may. However, the first step is obvious enough: unless there is a sense in which the being on whom a duty is laid is free to follow or not to follow its command, there is no sense in which duty is possible. This ought ye to do; but alas you cannot! This ought ye to do, and besides you can’t help doing it! These expressions equally rob the ought of meaning. We can quite see that without freedom, duty is meaningless. Yet the beings on whom the commands of duty are laid are men like you and me, and in such beings we notice that what freedom they have is limited in a peculiar way. We are in the habit of attributing to each a certain nature or character that we try to regard as working itself out--if not in all--yet in many and various situations. But in this attempt to explain conduct in terms of character and its expression, we are constantly baffled by what seems to us a duality or even multiplicity of characters in the same individual. In this man we explain a certain part of his conduct as the outcome of a strong imperious animality; but another part shows his passion restrained by motives of honor, kindness, sympathy. Two natures are at war in him, and as we are likely to think of one of these as more really his than the other, we represent him as struggling to conquer himself. Well, this warfare of a man with himself is one of the commonest things in life, and life itself shows that a higher or better self may often enough win the victory over and free itself from a baser and lower disposition. But life shows too that the struggle is long and bitter, so long that a lifetime is too short a span in which to secure a complete victory. Just in proportion as the higher self is high, does the struggle grow hard and lengthen itself out. If we conceive the self whose struggles we are watching to be the moral self as Kant describes it, all the love and lust of life seem to be arrayed against it. If it is to free itself, that is if we are to become completely moral agents, not a lifetime, nor a century, nor a million years, but the whole of eternity must be allowed us for our battling. But this means that the actor must be immortal, and so it is that for Kant the possibility of a completely moral being, free to act out his moral nature, presupposes immortality.