Experiences, as understood in the vulgar sense, there are none whatever. Our perceptions are purely token-values out of which experiences may be derived in the same way that practical results may be derived out of a sum of algebraical token-values by cancelling out one against the other. Here must be borne in mind what was treated of in our sixth Essay. With the perception “green” I get no positive content of knowledge, but merely the fact “not-red, not-yellow, not-blue,” and so forth. At this point we are confronted by the so-called epistemological problem, to the which, therefore, we now must devote some little attention. The question which forms the subject-matter of this problem is this: How is it possible from bare perceptions, mere sense-impressions, ever to arrive at conscious ideas, concepts, experiences? This problem is associated above all with the name of Kant. Starting with the idea that the sense-impressions received from without, contain no element out of which experience, _i.e._ an inner connection of individual impressions, could ever be developed, he taught that in the subject there was contained a business capital, so to speak, which, given _a priori_ to all experience, upon the occasion of the activity of the organs of sense, came to fruition. This business capital he called the given _a priori_ faculty of cognition. The practical significance of this teaching lies not so much in itself as in the fact that in contrast to it the position of the natural sciences is formulated all the more clearly and distinctly: the passage from bare perceptions to experience is of a purely empirical nature. The erroneous features in such ideas find some support in certain misunderstood physiological and pathological facts. Physiology teaches that the human infant does not “see” but only “looks,” _i.e._ he is the percipient of impressions from without in virtue of the existence of sense organs, but he attaches no meaning to these impressions. It is the same with the grown-up person after certain lesions of the cerebral cortex, in animals from which the brain has been artificially removed, and so forth. From this the conclusion is drawn that bare perceptions may be transmuted into experiences and that the condition of experience can again sink back into a condition of bare perception. Such ideas are supported by the teachings of many philosophers who make the young living being to enter the world as a _tabula rasa_, so to speak--as an empty pot which only now is to be filled with material from this world.