As Kant had to allow that God and immortality were completely superfluous in the world of our experience, he was obliged to look for a world "beyond" experience for them, and thus the spaceless and timeless world of things in themselves corresponded exactly to his needs.
The best proof for the existence of God and immortality in this world of the "beyond" Kant obtained from the moral law. Thus we find with him, as with Plato, that the repudiation of the naturalist explanation and the belief in a special world of spirits, or, if it be preferred, a world of spirits lending each other mutual support, render it necessary.
How, however, did Kant manage to obtain further insight into this spirit world? The "Critique of Pure Reason" only allowed him to say of it that it was timeless and spaceless. Now this spacelessness has to be filled up with a content. Even for that Kant has an idea.
The unknowable world of things in themselves becomes at least partly knowable directly one succeeds in getting hold of a thing in itself. And this Kant finds in the personality of man. I am for myself at once phenomenon and thing in itself. My pure reason is a thing in itself. As a part of the sensuous world I am subject to the chain of cause and effect, therefore to necessity, as a thing in itself I am free, that is, my actions are not determined by the causes of the world of the senses, but by the moral law dwelling within me, which springs from the pure reason and calls out to
Scotland. … The father a saddler by profession, maintained in his name the Scottish spelling Cant; the Philosopher first changed the letters to prevent the false pronounciation as Zant. (Kuno Fischer, "History of Modern Philosophy" Vol. III., page 52, German Ed.). His family were very religious and this influence Kant never got over. Not less than Kant is Cant related to puritan piety.
The word signified first the puritan method of singing, then the puritan, the religious, and finally the customary thoughtless oft-repeated phrases to which men submit themselves. Bernstein appealed in his assumption of Socialism for a Kant as an ally against the materialist "Party-Cant"
