Thus it is that Leibniz not only denies the equivalence of soul and consciousness, but asserts that the fundamental error of the psychology of the Cartesians (and here, at least, Locke is a Cartesian) is in identifying them. He asserts that "unconscious ideas" are of as great importance in psychology as molecules are in physics. They are the link between unconscious nature and the conscious soul. Nothing happens all at once; nature never makes jumps; these facts stated in the law of continuity necessitate the existence of activities, which may be called ideas, since they belong to the soul and yet are not in consciousness. When, therefore, Locke asks how an innate idea can exist and the soul not be conscious of it, the answer is at hand. The "innate idea" exists as an activity of the soul by which it represents--that is, expresses--some relation of the universe, although we have not yet become conscious of what is contained or enveloped in this activity. To become conscious of the innate idea is to lift it from the sphere of nature to the conscious life of spirit. And thus it is, again, that Leibniz can assert that all ideas whatever proceed from the depths of the soul. It is because it is the very being of the soul as a monad to reflect "from its point of view" the world. In this way Leibniz brings the discussion regarding innate ideas out of the plane of examination into a matter of psychological fact into a consideration of the essential nature of spirit. An innate idea is now seen to be one of the relations by which the soul reproduces some relation which constitutes the universe of reality, and at the same time realizes its own individual nature. It is one reflection from that spiritual mirror, the soul. With this enlarged and transformed conception of an idea apt to be so meagre we may well leave the discussion. There has been one mind at least to which the phrase "innate ideas" meant something worth contending for, because it meant something real. CHAPTER V. SENSATION AND EXPERIENCE.