Thus every universal, original force of nature is nothing but a low grade of the objectification of will, and we call every such grade an eternal Idea in Plato's sense. But a law of nature is the relation of the Idea to the form of its manifestation. This form is time, space, and causality, which are necessarily and inseparably connected and related to each other. Through time and space the Idea multiplies itself in innumerable phenomena, but the order according to which it enters these forms of multiplicity is definitely determined by the law of causality; this law is as it were the norm of the limit of these phenomena of different Ideas, in accordance with which time, space, and matter are assigned to them. This norm is therefore necessarily related to the identity of the aggregate of existing matter, which is the common substratum of all those different phenomena. If all these were not directed to that common matter in the possession of which they must be divided, there would be no need for such a law to decide their claims. They might all at once and together fill a boundless space throughout an endless time. Therefore, because all these phenomena of the eternal Ideas are directed to one and the same matter, must there be a rule for their appearance and disappearance; for if there were not, they would not make way for each other. Thus the law of causality is essentially bound up with that of the permanence of substance; they reciprocally derive significance from each other. Time and space, again, are related to them in the same way. For time is merely the possibility of conflicting states of the same matter, and space is merely the possibility of the permanence of the same matter under all sorts of conflicting states. Accordingly, in the preceding book we explained matter as the union of space and time, and this union shows itself as change of the accidents in the permanence of the substance, of which causality or becoming is the universal possibility. And accordingly, we said that matter is through and through causality. We explained the understanding as the subjective correlative of causality, and said matter (and thus the whole world as idea) exists only for the understanding; the understanding is its condition, its supporter as its necessary correlative. I repeat all this in passing, merely to call to mind what was demonstrated in the First Book, for it is necessary for the complete understanding of these two books that their inner agreement should be observed, since what is inseparably united in the actual world as its two sides, will and idea, has, in order that we might understand each of them more clearly in isolation, been dissevered in these two books.
It may not perhaps be superfluous to elucidate further by an example how the law of causality has meaning only in relation to time and space, and the matter which consists in the union of the two. For it determines the limits in accordance with which the phenomena of the forces of nature divide themselves in the possession of matter, while the original forces of nature, as the immediate objectification of will, which, as a thing in itself, is not subordinated to the principle of sufficient reason, lie outside these forms, within which alone all etiological explanation has validity and meaning, and just on that account can never lead us to the inner reality of nature. For this purpose let us think of some kind of machine constructed according to the laws of mechanics. Iron weights begin the motion by their gravity; copper wheels resist by their rigidity, affect and raise each other and the lever by their impenetrability, and so on. Here gravity, rigidity, and impenetrability are original unexplained forces; mechanics only gives us the condition under which, and the manner in which, they manifest themselves, appear, and govern a definite matter, time, and place. If, now, a strong magnet is made to attract the iron of the weight, and overcome its gravity, the movement of the machine stops, and the matter becomes forthwith the scene of quite a different force of nature—magnetism, of which etiology again gives no further explanation than the condition under which it appears. Or let us suppose that the copper discs of such a machine are laid upon zinc plates, and an acid solution introduced between them. At once the same matter of the machine has become subject to another original force, galvanism, which now governs it according to its own laws, and reveals itself in it through its phenomena; and etiology can again tell us nothing about this force except the conditions under which, and the laws in accordance with which, it manifests itself. Let us now raise the temperature and add pure acid; the whole machine burns; that is to say, once more an entirely different force of nature, chemical energy, asserts at this time and in this place irresistible claims to this particular matter, and reveals itself in it as Idea, as a definite grade of the objectification of will. The calcined metal thus produced now unites with an acid, and a salt is obtained which forms itself into crystals. These are the phenomena of another Idea, which in itself is again quite inexplicable, while the appearance of its phenomena is dependent upon certain conditions which etiology can give us. The crystals dissolve, mix with other materials, and vegetation springs up from them—a new phenomenon of will: and so the same permanent matter may be followed ad infinitum, to observe how now this and now that natural force obtains a right to it and temporarily takes possession of it, in order to appear and reveal its own nature. The condition of this right, the point of time and space at which it becomes valid, is given by causality, but the explanation founded upon this law only extends thus far. The force itself is a manifestation of will, and as such is not subject to the forms of the principle of sufficient reason, that is, it is groundless. It lies outside all time, is omnipresent, and seems as it were to wait constantly till the circumstances occur under which it can appear and take possession of a definite matter, supplanting the forces which have reigned in it till then. All time exists only for the phenomena of such a force, and is without significance for the force itself. Through thousands of years chemical forces slumber in matter till the contact with the reagents sets them free; then they appear; but time exists only for the phenomena, not for the forces themselves. For thousands of years galvanism slumbered in copper and zinc, and they lay quietly beside silver, which must be consumed in flame as soon as all three are brought together under the required conditions. Even in the organic kingdom we see a dry seed preserve the slumbering force through three thousand years, and when at last the favourable circumstances occur, grow up as a plant.35
If by this exposition the difference between a force of nature and all its phenomena has been made quite distinct; if we have seen clearly that the former is the will itself at this particular grade of its objectification, but that multiplicity comes to phenomena only through time and space, and that the law of causality is nothing but the determination of the position of these phenomena in time and space; then we shall recognise the complete truth and the deep meaning of Malebranche's doctrine of occasional causes (causes occasionelles). It is well worth while comparing this doctrine of his, as he explains it in the “Recherches de la Vérite,” both in the 3rd Chapter of the second part of the 6th Book, and in the éclaircissements appended to this chapter, with this exposition of mine, and observing the complete agreement of the two doctrines in the case of such different systems of thought. Indeed I cannot help admiring how Malebranche, though thoroughly involved in the positive dogmas which his age inevitably forced upon him, yet, in such bonds and under such a burden, hit the truth so happily, so correctly, and even knew how to combine it with these dogmas, at all events verbally.
For the power of truth is incredibly great and of unspeakable endurance. We find constant traces of it in all, even the most eccentric and absurd dogmas, of different times and different lands—often indeed in strange company, curiously mixed up with other things, but still recognisable. It is like a plant that germinates under a heap of great stones, but still struggles up to the light, working itself through with many deviations and windings, disfigured, worn out, stunted in its growth—but yet, to the light.
In any case Malebranche is right: every natural cause is only an occasional cause. It only gives opportunity or occasion for the manifestation of the one indivisible will which is the “in-itself” of all things, and whose graduated objectification is the whole visible world. Only the appearance, the becoming visible, in this place, at this time, is brought about by the cause and is so far dependent on it, but not the whole of the phenomenon, nor