to the intelligible substratum, of the phenomena which in this way arise for us. Thus that on the occasion of certain sensations occurring in my organs of sense there arises in my head a perception of things which are extended in space, permanent in time, and causally efficient by no means justifies the assumption that they also exist in themselves, _i.e._, that such things with these properties belonging absolutely to themselves exist independently and outside of my head. This is the true outcome of the Kantian philosophy. It coincides with an earlier result of Locke’s, which is just as true, but far more easily understood. For although, as Locke’s doctrine permits, external things are absolutely assumed as the causes of sensations, yet there can be no _resemblance_ between the sensation in which the _effect_ consists and the objective nature of the _cause_ which occasions it. For the sensation, as organic function, is primarily determined by the highly artificial and complicated nature of our organs of sense. It is therefore merely excited by the external cause, but is then perfected entirely in accordance with its own laws, and thus is completely subjective. Locke’s philosophy was the criticism of the functions of sense; Kant has given us the criticism of the functions of the brain. But to all this we have yet to add the Berkeleian result, which has been revised by me, that every object, whatever its origin may be, is _as object_ already conditioned by the subject, is in fact merely its _idea_. The aim of realism is indeed the object without subject; but it is impossible even to conceive such an object distinctly. From this whole inquiry it follows with certainty and distinctness that it is absolutely impossible to attain to the comprehension of the inner nature of things upon the path of mere _knowledge_ and _perception_. For knowledge always comes to things from without, and therefore must for ever remain outside them. This end would only be reached if we could find _ourselves_ in the inside of things, so that their inner nature would be known to us directly. Now, how far this is actually the case is considered in my second book. But so long as we are concerned, as in this first book, with objective comprehension, that is, with _knowledge_, the world is, and remains for us, a mere _idea_, for here there is no possible path by which we can cross over to it.