He made the real evidence for religion that of the moral sense, of the nonscience and hearts of men themselves. The real ground of religious conviction is the religious experience. He thus set free both science and religion from an embarrassment under which both laboured, and by which both had been injured. Kant parted company with the empirical philosophy which had held that all knowledge arises from without, comes from experienced sensations, is essentially perception. This theory had not been able to explain the fact that human experience always conforms to certain laws. On the other hand, the philosophy of so-called innate ideas had sought to derive all knowledge from the constitution of the mind itself. It left out of consideration the dependence of the mind upon experience. It tended to confound the creations of its own speculation with reality, or rather, to claim correspondence with fact for statements which had no warrant in experience. There was no limit to which this speculative process might not be pushed. By this process the medieval theologians, with all gravity, propounded the most absurd speculations concerning nature. By this process men made the most astonishing declarations upon the basis, as they supposed, of revelation. They made allegations concerning history and the religious experience which the most rudimentary knowledge of history or reflection upon consciousness proved to be quite contrary to fact. Both empiricism and the theory of innate ideas had agreed in regarding all knowledge as something given, from without or from within. The knowing mind was only a passive recipient of impressions thus imparted to it. It was as wax under the stylus, _tabula rasa_, clean paper waiting to be written upon. Kant departed from this radically. He declared that all cognition rests upon the union of the mind's activity with its receptivity. The material of thought, or at least some of the materials of thought, must be given us in the multiformity of our perceptions, through what we call experience from the outer world. On the other hand, the formation of this material into knowledge is the work of the activity of our own minds. Knowledge is the result of the systematising of experience and of reflection upon it. This activity of the mind takes place always in accordance with the mind's own laws. Kant held them to the absolute dependence of knowledge upon material applied in experience. He compared himself to Copernicus who had taught men that they themselves revolved around a central fact of the universe. They had supposed that the facts revolved about them. The central fact of the intellectual world is experience. This experience seems to be given us in the forms of time and space and cause. These are merely forms of the mind's own activity. It is not possible for us to know 'the thing in itself,' the _Ding an sich_ in Kant's phrase, which is the external factor in any sensation or perception. We cannot distinguish that