All this, however, rests on the fundamental distinction between dogmatic and critical or transcendental philosophy. Whoever wishes to make this quite clear to himself, and realise it by means of an example, may do so very briefly by reading, as a specimen of dogmatic philosophy, an essay of Leibnitz entitled "De Rerum Originatione Radicali," and printed for the first time in the edition of the philosophical works of Leibnitz by Erdmann (vol. i. p. 147). Here the origin and excellence of the world is demonstrated a priori, so thoroughly in the manner of realistic dogmatism, on the ground of the veritates æternæ and with the assistance of the ontological and cosmological proofs. It is indeed once admitted, by the way, that experience shows the exact opposite of the excellence of the world here demonstrated ; but experience is therefore given to understand that it knows nothing of the matter, and ought to hold its tongue when philosophy has spoken a priori. Now, with Kant, the critical philosophy appeared as the opponent of this whole method. It takes for its problem just these veritates æternæ, which serve as the foundation of every such dogmatic structure, investigates their origin, and finds it in the human mind, where they spring from the peculiar forms which belong to it, and which it carries in itself for the purpose of comprehending an objective world. Thus, here, in the brain, is the quarry which supplies the material for that proud dogmatic edifice. But because the critical philosophy, in order to attain to this result, was obliged to go beyond the veritates æternæ upon which all the preceding dogmatism was founded, and make these truths themselves the objects of investigation, it became transcendental philosophy. From this, then, it also follows that the objective world, as we know it, does not belong to the true being of the thing in itself, but is merely its phenomenal appearance conditioned by those very forms which lie a priori in the intellect (i.e., the brain), therefore it cannot contain anything but phenomena.
