§ 17.

In the first book we considered the representation only as such, and hence only according to the general form. It is true that, so far as the abstract representation, the concept, is concerned, we also obtained a knowledge of it according to its content, in so far as it has all content and meaning only through its relation to the representation of perception, without which it would be worthless and empty. Therefore, directing our attention entirely to the representation of perception, we shall endeavour to arrive at a knowledge of its content, its more precise determinations, and the forms it presents to us. It will be of special interest for us to obtain information about its real significance, that significance, otherwise merely felt, by virtue of which these pictures or images do not march past us strange and meaningless, as they would otherwise inevitably do, but speak to us directly, are understood, and acquire an interest that engrosses our whole nature.

We direct our attention to mathematics, natural science, and philosophy, each of which holds out the hope that it will furnish a part of the information desired. In the first place, we find philosophy to be a monster with many heads, each of which speaks a different language. Of course, they are not all at variance with one another on the point here mentioned, the significance of the representation of perception. For, with the exception of the Sceptics and Idealists, the others in the main speak fairly consistently of an object forming the basis of the representation. This object indeed is different in its whole being and nature from the representation, but yet is in all respects as like it as one egg is like another. But this does not help us, for we do not at all know how to distinguish that object from the representation. We find that the two are one and the same, for every object always and eternally presupposes a subject, and thus remains representation. We then recognize also that being-object belongs to the most universal form of the representation, which is precisely the division into object and subject. Further, the principle of sufficient reason, to which we here refer, is also for us only the form of the representation, namely the regular and orderly combination of one representation with another, and not the combination of the whole finite or infinite series of representations with something which is not representation at all, and is therefore not capable of being in any way represented. We spoke above of the Sceptics and Idealists, when discussing the controversy about the reality of the external world.

Now if we look to mathematics for the desired more detailed knowledge of the representation of perception, which we have come to know only quite generally according to the mere form, then this science will tell us about these representations only in so far as they occupy time and space, in other words, only in so far as they are quantities. It will state with extreme accuracy the How-many and the How-large; but as this is always only relative, that is to say, a comparison of one representation with another, and even that only from the one-sided aspect of quantity, this too will not be the information for which principally we are looking.

Finally, if we look at the wide province of natural science, which is divided into many fields, we can first of all distinguish two main divisions. It is either a description of forms and shapes, which I call Morphology; or an explanation of changes, which I call Etiology. The former considers the permanent forms, the latter the changing matter, according to the laws of its transition from one form into another. Morphology is what we call natural history in its whole range, though not in the literal sense of the word. As botany and zoology especially, it teaches us about the various, permanent, organic, and thus definitely determined forms in spite of the incessant change of individuals; and these forms constitute a great part of the content of the perceptive representation. In natural history they are classified, separated, united, and arranged according to natural and artificial systems, and brought under concepts that render possible a survey and knowledge of them all. There is further demonstrated an infinitely fine and shaded analogy in the whole and in the parts of these forms which runs through them all (unité de plan),53 by virtue of which they are like the many different variations on an unspecified theme. The passage of matter into those forms, in other words the origin of individuals, is not a main part of the consideration, for every individual springs from its like through generation, which everywhere is equally mysterious, and has so far baffied clear knowledge. But the little that is known of this finds its place in physiology, which belongs to etiological natural science. Mineralogy, especially where it becomes geology, though it belongs mainly to morphology, also inclines to this etiological science. Etiology proper includes all the branches of natural science in which the main concern everywhere is knowledge of cause and effect. These sciences teach how, according to an invariable rule, one state of matter is necessarily followed by another definite state; how one definite change necessarily conditions and brings about another definite change; this demonstration is called explanation. Here we find principally mechanics, physics, chemistry, and physiology.

But if we devote ourselves to its teaching, we soon become aware that the information we are chiefly looking for no more comes to us from etiology than it does from morphology. The latter presents us with innumerable and infinitely varied forms that are nevertheless related by an unmistakable family likeness. For us they are representations that in this way remain eternally strange to us, and, when considered merely in this way, they stand before us like hieroglyphics that are not understood. On the other hand, etiology teaches us that, according to the law of cause and effect, this definite condition of matter produces that other condition, and with this it has explained it, and has done its part. At bottom, however, it does nothing more than show the orderly arrangement according to which the states or conditions appear in space and time, and teach for all cases what phenomenon must necessarily appear at this time and in this place. It therefore determines for them their position in time and space according to a law whose definite content has been taught by experience, yet whose universal form and necessity are known to us independently of experience. But in this way we do not obtain the slightest information about the inner nature of any one of these phenomena. This is called a natural force, and lies outside the province of etiological explanation, which calls the unalterable constancy with which the manifestation of such a force appears whenever its known conditions are present, a law of nature. But this law of nature, these conditions, this appearance in a definite place at a definite time, are all that it knows, or ever can know. The force itself that is manifested, the inner nature of the phenomena that appear in accordance with those laws, remain for it an eternal secret, something entirely strange and unknown, in the case of the simplest as well as of the most complicated phenomenon. For although etiology has so far achieved its aim most completely in mechanics, and least so in physiology, the force by virtue of which a stone falls to the ground, or one body repels another, is, in its inner nature, just as strange and mysterious as that which produces the movements and growth of an animal. Mechanics presupposes matter, weight, impenetrability, communicability of motion through impact, rigidity, and so on as unfathomable; it calls them forces of nature, and their necessary and regular appearance under certain conditions a law of nature. Only then does its explanation begin, and that consists in stating truly and with mathematical precision how, where, and when each force manifests itself, and referring to one of those forces every phenomenon that comes before it. Physics, chemistry, and physiology do the same in their province, only they presuppose much more and achieve less. Consequently, even the most perfect etiological explanation of the whole of nature would never be more in reality than a record of inexplicable forces, and a reliable statement of the rule by which their phenomena appear, succeed, and make way for one another in time and space. But the inner nature of the forces that thus appear was always bound to be left unexplained by etiology, which had to stop at the phenomenon and its arrangement, since the law followed by etiology does not go beyond this. In this respect it could be compared to a section of a piece of marble showing many different veins side by side, but not letting us know the course of these veins from the interior of the marble to the surface. Or, if I may be permitted a facetious comparison, because it is more striking, the philosophical investigator must always feel in regard to the complete etiology of the whole of nature like a man who, without knowing how, is brought into a company quite unknown to him, each member of which in turn presents to him another as his friend and cousin, and thus makes them sufficiently acquainted. The man himself, however, while assuring each person introduced of his pleasure at meeting him, always has on his lips the question: “But how the deuce do I stand to the whole company?”

Hence, about those phenomena known by us only as our representations, etiology can never give us the desired information that leads us beyond them. For after all its explanations, they still stand quite strange before us, as mere representations whose significance we do not understand. The causal connexion merely gives the rule and relative order of their appearance in space and time, but affords us no further knowledge of that which so appears. Moreover, the law of causality itself has validity only for representations, for objects of a definite class, and has meaning only when they are assumed. Hence, like these objects themselves, it always exists only in relation to the subject, and so conditionally. Thus it is just as well known when we start from the subject, i.e., a priori, as when we start from the object, i.e., a posteriori, as Kant has taught us.

But what now prompts us to make enquiries is that we are not satisfied with knowing that we have representations, that they are such and such, and that they are connected according to this or that law, whose general expression is always the principle of sufficient reason. We want to know the significance of those representations; we ask whether this world is nothing more than representation. In that case, it would inevitably pass by us like an empty dream, or a ghostly vision not worth our consideration. Or we ask whether it is something else, something in addition, and if so what that something is. This much is certain, namely that this something about which we are enquiring must be by its whole nature completely and fundamentally different from the representation; and so the forms and laws of the representation must be wholly foreign to it. We cannot, then, reach it from the representation under the guidance of those laws that merely combine objects, representations, with one another; these are the forms of the principle of sufficient reason.

Here we already see that we can never get at the inner nature of things from without. However much we may investigate, we obtain nothing but images and names. We are like a man who goes round a castle, looking in vain for an entrance, and sometimes sketching the façades. Yet this is the path that all philosophers before me have followed.