from this perception which arises under such a variety of conditions, all our conceptions are drawn. They have all their content from it, or even only in relation to it. Therefore, as Kant says, they are only for immanent, not for transcendental, use; that is to say, these conceptions of ours, this first material of thought, and consequently still more the judgments which result from their combination, are unfitted for the task of thinking the nature of things in themselves, and the true connection of the world and existence; indeed, to undertake this is analogous to expressing the stereometrical content of a body in square inches. For our intellect, originally only intended to present to an individual will its paltry aims, comprehends accordingly mere relations of things, and does not penetrate to their inner being, to their real nature. It is therefore a merely superficial force, clings to the surface of things, and apprehends mere species transitivas, not the true being of things. From this it arises that we cannot understand and comprehend any single thing, even the simplest and smallest, through and through, but something remains entirely inexplicable to us in each of them. Just because the intellect is a product of nature, and is therefore only intended for its ends, the Christian mystics have very aptly called it “the light of nature,” and driven it back within its limits; for nature is the object to which alone it is the subject. The thought from which the Critique of Pure Reason has sprung really lies already at the foundation of this expression. That we cannot comprehend the world on the direct path, i. e., through the uncritical, direct application of the intellect and its data, but when we reflect upon it become ever more deeply involved in insoluble mysteries, points to the fact that the intellect, thus knowledge itself, is secondary, a mere product, brought about by the development of the inner being of the world, which consequently till then preceded it, and it at last appeared as a breaking through to the light out of the obscure depths of the unconscious striving the nature of which exhibits itself as will to the self-consciousness which now at once arises. That which preceded knowledge as its condition, whereby it first became possible, thus its own basis, cannot be directly comprehended by it; as the eye cannot see itself. It is rather the relations of one existence to another, exhibiting themselves upon the surface of things, which alone are its affair, and are so only by means of the apparatus of the intellect, its forms, space, time, and causality. Just because the world has made itself without the assistance of knowledge, its whole being does not enter into knowledge, but knowledge presupposes the existence of the world; on which account the origin of the world does not lie within its sphere. It is accordingly limited to the relations between the things which lie before it, and is thus sufficient for the individual will, for the service of which alone it appeared. For the intellect is, as has been shown, conditioned by nature, lies in it, belongs to it, and cannot therefore place itself over against it as something quite foreign to it, in order thus to take up into itself its whole nature, absolutely, objectively, and thoroughly. It can, if fortune favours it, understand all that is in nature, but not nature itself, at least not directly.
However discouraging to metaphysics this essential limitation of the intellect may be, which arises from its nature and origin, it has yet another side which is very consoling. It deprives the direct utterances of nature of their unconditional validity, in the assertion of which naturalism proper consists. If, therefore, nature presents to us every living thing as appearing out of nothing, and, after an ephemeral existence, returning again for ever to nothing, and if it seems to take pleasure in the unceasing production of new beings, in order that it may be able unceasingly to destroy, and, on the other hand, is unable to bring anything permanent to light; if accordingly we are forced to recognise matter as that which alone is permanent, which never came into being and never passes away, but brings forth all things from its womb, whence its name appears to be derived from mater rerum, and along with it, as the father of things, form, which, just as fleeting as matter is permanent, changes really every moment, and can only maintain itself so long as it clings as a parasite to matter (now to one part of it, now to another), but when once it entirely loses hold, disappears, as is shown by the palæotheria and the ichthyosaurians, we must indeed recognise this as the direct and genuine utterance of nature, but on account of the origin of the intellect explained above, and the nature of it which results from this origin, we cannot ascribe to this utterance an unconditional truth, but rather only an entirely conditional truth, which Kant has appropriately indicated as such by calling it the phenomenon in opposition to the thing in itself.
If, in spite of this essential limitation of the intellect, it is possible, by a circuitous route, to arrive at a certain understanding of the world and the nature of things, by means of reflection widely pursued, and the skilful combination of objective knowledge directed towards without, with the data of self-consciousness, this will yet be only a very limited, entirely indirect, and relative understanding, a parabolical translation into the forms of knowledge, thus a quadam prodire tenus, which must always leave many problems still unsolved. On the other hand, the fundamental error of the old dogmatism in all its forms, which was destroyed by Kant, was this, that it started absolutely from knowledge, i.e., the world as idea, in order to deduce and construct from its laws being in general, whereby it accepted that world of idea, together with its laws, as absolutely existing and absolutely real; while its whole existence is throughout relative, and a mere result or phenomenon of the true being which lies at its foundation, – or, in other words, that it constructed an ontology when it had only materials for a dianoiology. Kant discovered the subjectively conditioned and therefore entirely immanent nature of knowledge, i. e., its unsuitableness for transcendental use, from the constitution of knowledge itself; and therefore he very appropriately called his doctrine the Critique of Reason. He accomplished this partly by showing the important and thoroughly a priori part of all knowledge, which, as throughout subjective, spoils all objectivity, and partly by professedly proving that if they were followed out to the end the principles of knowledge, taken as purely objective, led to contradictions. He had, however, hastily assumed that, apart from objective knowledge, i. e., apart from the world as idea, there is nothing given us except conscience, out of which he constructed the little that still remained of metaphysics, his moral theology, to which, however, he attributed absolutely only a practical validity, and no theoretical validity at all. He had overlooked that although certainly objective knowledge, or the world as idea, affords nothing but phenomena, together with their phenomenal connection and regressus, yet our own nature necessarily also belongs to the world of things in themselves, for it must have its root in it. But here, even if the root itself cannot be brought to light, it must be possible to gather some data for the explanation of the connection of the world of phenomena with the inner nature of things. Thus here lies the path upon which I have gone beyond Kant and the limits which he drew, yet always restricting myself to the ground of reflection, and consequently of honesty, and therefore without the vain pretension of intellectual intuition or absolute thought which characterises the period of pseudo-philosophy between Kant and me. In his proof of the insufficiency of rational knowledge to fathom the nature of the world Kant started from knowledge as a fact, which our consciousness affords us, thus in this sense he proceeded a posteriori. But in this chapter, and also in my work, “Ueber den Willen in der Natur,” I have sought to show what knowledge is in its nature and origin, something secondary, designed for individual ends; whence it follows that it must be insufficient to fathom the nature of the world. Thus so far I have reached the same goal a priori. But one never knows anything wholly and completely until one has gone right round it for that purpose, and has got back to it from the opposite side from which one started. Therefore also, in the case of the important fundamental knowledge here considered, one must not merely go from the intellect to the knowledge of the world, as Kant has done, but also from the world, taken as given, to the intellect, as I have undertaken here. Then this physiological consideration, in the wider sense, becomes the supplement of that ideological, as the French say, or, more accurately, transcendental consideration.
In the above, in order not to break the thread of the exposition, I have postponed the explanation of one point which I touched upon. It was this, that in proportion as, in the ascending series of animals, the intellect appears ever more developed and complete, knowledge always separates itself more distinctly from will, and thereby becomes purer. What is essential upon this point will be found in my work, “Ueber
