To this last posture of materialism, a competent understanding of Kant is the _only reply that has ever been needed_. It is simply of no consequence to the case what states of consciousness precede or follow other states of consciousness. Let it be granted (whether true or not) that "phenomena of consciousness to which we give the names of matter and motion" precede all others. What of it? Kant has proved to us that _no_ phenomenon of consciousness--no matter, no motion, no sensation--and, beyond all these, no time and no space, in which all the rest appear--has, or can have, _any existence_, except as put into unity, form, and order, by the unity, form, and order of mind. If both "the synthesis of apprehension" and "the synthesis of apperception" enter into any state of consciousness named matter, _to give it birth_, there is no possibility that the element of intelligence can be an _after-birth_ of the process. All our objects, then, from a germ cell to the horizon, are constructed such through a mental principle innate in our own structure. But here it must be re-iterated and re-emphasized that whatever we, as units of mind, may embody in objects as _form_, the _filling_ of them is not ours. It has a source apart. The filling of our objects comes from "the ultimate non-ego," the "background of matter." This ultimate non-ego was a heritage to Kant from British idealism. He took it for granted at his first step and held by it unchanged when he was old and exhausted. He called it the "noumenon," the "real correlate of matter," and pluralized it as "things in themselves." But he insisted, as firmly as Herbert Spencer has since done, that the "noumenon" is "unknown and unknowable."