Metaphysics is ripe for a similar advance. It must be promoted to the rank of positive science by the transforming power of an analogous method. The fundamental and distinguishing characteristic of mathematical and physical procedure is the legislative power to which reason lays claim. Such procedure, if generalised and extended, will supply the required method of the new philosophy. Reason must be regarded as self-legislative in all the domains of our possible knowledge. _Objects must be viewed as conforming to human thought, not human thought to the independently real._ This is the “hypothesis” to which Kant has given the somewhat misleading title, “Copernican.”[113] The _method of procedure_ which it prescribes is, he declares, analogous to that which was followed by Copernicus, and will be found to be as revolutionary in its consequences. In terms of this hypothesis a complete and absolutely certain metaphysics, valid now and for all time, can be created at a stroke. The earliest and oldest enterprise of the human mind will achieve a new beginning. Metaphysics, the mother of all the sciences, will renew her youth, and will equal in assurance, as she surpasses in dignity, the offspring of her womb. From this new standpoint Kant develops phenomenalism on rationalist lines. He professes to prove that though our knowledge is only of appearances, it is conditioned by _a priori_ principles. His “Copernican hypothesis,” so far from destroying positive science, is, he claims, merely a philosophical extension of the method which it has long been practising. Since all science worthy of the name involves _a priori_ elements, it can be accounted for only in terms of the new hypothesis. Only if objects are regarded as conforming to our forms of intuition, and to our modes of conception, can they be anticipated by _a priori_ reasoning. Science can be _a priori_ just because, properly understood, it is not a rival of metaphysics, and does not attempt to define the absolutely real.