upon faith, is just exactly "the transcendental realist who plays the empirical idealist" censured by Kant in the "Critique of Pure Reason," first edition, p. 369.
The true idealism, on the contrary, is not the empirical but the transcendental. This leaves the empirical reality of the world untouched, but holds fast to the fact that every object, thus the empirically real in general, is conditioned in a twofold manner by the subject; in the first place materially or as object generally, because an objective existence is only conceivable as opposed to a subject, and as its idea; in the second place formally, because the mode of existence of an object, i.e., its being perceived (space, time, causality), proceeds from the subject, is prearranged in the subject. Therefore with the simple or Berkeleian idealism, which concerns the object in general, there stands in immediate connection the Kantian idealism, which concerns the specially given mode or manner of objective existence. This proves that the whole material world, with its bodies, which are extended in space and, by means of time, have causal relations to each other, and everything that depends upon this – that all this is not something which is there independently of our head, but essentially presupposes the functions of our brain by means of which and in which alone such an objective arrangement of things is possible. For time, space, and causality, upon which all those real and objective events rest, are them selves nothing more than functions of the brain; so that thus the unchangeable order of things which affords the criterion and clue to their empirical reality itself proceeds only from the brain, and has its credentials from this alone. All this Kant has expounded fully and thoroughly; only he does not speak of the brain, but calls it "the faculty of knowledge." Indeed he has attempted to prove that when that objective order in time, space, causality, matter, &c., upon which all the events of the real world ultimately rest, is properly considered, it cannot even be conceived as a self-existing order, i.e., an order of the thing in itself,
