not know the immaterial substance, soul. The most recent advances in the physiology of the nervous system, through Sir Charles Bell, Magendie, Marshall Hall, and others, have also enriched and corrected the material of this method of consideration. A philosophy which, like the Kantian, entirely ignores this point of view for the intellect is one-sided, and consequently inadequate. It leaves an impassable gulf between our philosophical and our physiological knowledge, with which we can never find satisfaction.
Although what I have said in the two preceding chapters concerning the life and the activity of the brain belongs to this method of consideration, and in the same way all the discussions to be found under the heading, “Pflanzenphysiologie,” in the essay, “Ueber den Willen in der Natur,” and also a portion of those under the heading “Vergleichende Anatomie,” are devoted to it, the following exposition of its results in general will be by no means superfluous.
We become most vividly conscious of the glaring contrast between the two methods of considering the intellect opposed to each other above if we carry the matter to the extreme and realise that what the one, as reflective thought and vivid perception, directly assumes and makes its material is for the other nothing more than the physiological function of an internal organ, the brain; nay, that we are justified in asserting that the whole objective world, so boundless in space, so infinite in time, so unsearchable in its perfection, is really only a certain movement or affection of the pulpy matter in the skull. We then ask in astonishment: what is this brain whose function produces such a phenomenon of all phenomena? What is the matter which can be refined and potentiated to such a pulp that the stimulation of a few of its particles becomes the conditional supporter of the existence of an objective world? The fear of such questions led to the hypothesis of the simple substance of an immaterial soul, which merely dwelt in the brain. We say boldly: this pulp also, like every vegetable or animal part, is an organic structure, like all its poorer relations in the inferior accommodation of the heads of our irrational brethren, down to the lowest, which scarcely apprehends at all; yet that organic pulp is the last product of nature, which presupposes all the rest. But in itself, and outside the idea, the brain also, like everything else, is will. For existing for another is being perceived; being in itself is willing: upon this it depends that on the purely objective path we never attain to the inner nature of things; but if we attempt to find their inner nature from without and empirically, this inner always becomes an outer again in our hands, – the pith of the tree, as well as its bark; the heart of the animal, as well as its hide; the white and the yolk of an egg, as well as its shell. On the other hand, upon the subjective path the inner is accessible to us at every moment; for we find it as the will primarily in ourselves, and must, by the clue of the analogy with our own nature, be able to solve that of others, in that we attain to the insight that a being in itself independent of being known, i. e., of exhibiting itself in an intellect, is only conceivable as willing.
If now, in the objective comprehension of the intellect, we go back as far as we possibly can, we shall find that the necessity or the need of knowledge in general arises from the multiplicity and the separate existence of beings, thus from individuation. For suppose there only existed a single being, such a being would have no need of knowledge: because nothing would exist which was different from it, and whose existence it would therefore have to take up into itself indirectly through knowledge, i. e., image and concept. It would itself already be all in all, and therefore there would remain nothing for it to know, i. e., nothing foreign that could be apprehended as object. In the case of a multiplicity of beings, on the other hand, every individual finds itself in a condition of isolation from all the rest, and hence arises the necessity of knowledge. The nervous system, by means of which the animal individual primarily becomes conscious of itself, is bounded by a skin; yet in the brain that has attained to intellect it passes beyond this limit by means of its form of knowledge, causality, and thus there arises for it perception as a consciousness of other things, as an image of beings in space and time, which change in accordance with causality. In this sense it would be more correct to say, “Only the different is known by the different,” than as Empedocles said, “Only the like is known by the like,” which was a very indefinite and ambiguous proposition; although points of view may certainly also be conceived from which it is true; as, for instance, we may observe in passing that of Helvetius when he says so beautifully and happily: “Il n'y a que l'esprit qui sente l'esprit: c'est une corde qui ne frémit qu'à l'unison,” which corresponds with Xenophon's “σοφον ειναι δει τον επιγνωσομενον τον σοφον” (sapientem esse opportet eum, qui sapientem agniturus sit), and is a great sorrow. But now, again, from the other side we know that multiplicity of similars only becomes possible through time and space; thus through the forms of our knowledge. Space first arises in that the knowing subject sees externally; it is the manner in which the subject comprehends something as different from itself. But we also saw knowledge in general conditioned by multiplicity and difference. Thus knowledge and multiplicity, or individuation, stand and fall together, for they reciprocally condition each other. Hence it must be inferred that, beyond the phenomenon in the true being of all things, to which time and space, and consequently also multiplicity, must be foreign, there can also be no knowledge. Buddhism defines this as Pratschna Paramita, i. e., that which is beyond all knowledge (J. J. Schmidt, “On the Maha-Jana and Pratschna Paramita”). A “knowledge of things in themselves,” in the strictest sense of the word, would accordingly be already impossible from the fact that where the thing in itself begins knowledge ceases, and all knowledge is essentially concerned only with phenomena. For it springs from a limitation, by which it is made necessary, in order to extend the limits.
For the objective consideration the brain is the efflorescence of the organism; therefore only where the latter has attained its highest perfection and complexity does the brain appear in its greatest development. But in the preceding chapter we have recognised the organism as the objectification of the will; therefore the brain also, as a part of it, must belong to this objectification. Further, from the fact that the organism is only the visibility of the will, thus in itself is the will, I have deduced that every affection of the organism at once and directly affects the will, i. e., is felt as agreeable or painful. Yet, with the heightening of sensibility, in the higher development of the nervous system, the possibility arises that in the nobler, i. e., the objective, organs of sense (sight and hearing) the exquisitely delicate affections proper to them are perceived without in themselves and directly affecting the will, that is, without being either painful or agreeable, and that therefore they appear in consciousness as indifferent, merely perceived, sensations. But in the brain this heightening of sensibility reaches such a high degree that upon received impressions of sense a reaction even takes place, which does not proceed directly from the will, but is primarily a spontaneity of the function of understanding, which makes the transition from the directly perceived sensation of the senses to its cause; and since the brain then at once produces the form of space, there thus arises the perception of an external object. We may therefore regard the point at which the understanding makes the transition from the mere sensation upon the retina, which is still a mere affection of the body and therefore of the will, to the cause of that sensation, which it projects by means of its form of space, as something external and different from its own body, as the boundary between the world as will and the world as idea, or as the birthplace of the latter. In man, however, the spontaneity of the activity of the brain, which in the last instance is certainly conferred by the will, goes further than mere perception and immediate comprehension of causal relations. It extends to the construction of abstract conceptions out of these perceptions, and to operating with these conceptions, i. e., to thinking, as that in which his reason consists. Thoughts are therefore furthest removed from the affections of the body, which, since the body is the objectification of the will, may, through increased intensity, pass at once into pain, even in the organs of sense. Accordingly idea and thought may also be regarded as the efflorescence of the will, because they spring from the highest perfection and development of the organism; but the organism, in itself and apart from the idea, is the will. Of course, in my explanation, the existence of the body presupposes the world of idea; inasmuch as it also, as body
