immortal spirit, absolutely no proof in a theoretical point of view is possible for the human Reason, which can bring about even the least degree of belief. The ground of this is quite easy to comprehend. For determining our Ideas of the supersensible we have no material whatever, and we must derive this latter from things in the world of sense, which is absolutely inadequate for such an Object.

Thus, in the absence of all determination of it, nothing remains but the concept of a non-sensible something which contains the ultimate ground of the world of sense, but which does not furnish any knowledge (any amplification of the concept) of its inner constitution.