"Kant tells us that Space is the form of all external intuition, which is not true. He tells us that the consciousness of Space continues when the consciousness of all things contained in it is suppressed; which is also not true. From these alleged facts he infers that Space is an a priori form of intuition. I say infers, because this conclusion is not presented in necessary union with the premises, in the same way that the consciousness of duality is necessarily presented along with the consciousness of inequality; but it is a conclusion voluntarily drawn for the purpose of explaining the alleged facts. And then, that we may accept this conclusion, which is not necessarily presented along with these alleged facts which are not true, we are obliged to affirm several propositions which cannot be rendered into thought. When Space is itself contemplated, we have to conceive it as at once the form of intuition and the matter of intuition, which is impossible. We have to unite that which we are conscious of as Space with that which we are conscious of as the ego, and contemplate the one as a property of the other; which is impossible. We have, at the same time, to disunite that which we are conscious of as Space, from that which we are conscious of as the non-ego, and contemplate the one as separate from the other; which is also impossible. Further, this hypothesis, that Space is 'nothing else' than a form of intuition belonging wholly to the ego, commits us to one of the two alternatives, that the non-ego is formless, and that its form produces absolutely no effect upon the ego—both of which alternatives involve us in impossibilities of thought."—Principles of Psychology, § 399.—Advance Sheets from Fortnightly Review.