The World as Will and Idea, Vol. II — Arthur Schopenhauer, trans. Haldane & Kemp

(26) Every change in matter can take place only on account of another change which preceded it ; and therefore a first change, and thus also a first state of matter, is just as inconceivable as a beginning of time or a limit of space. (Principle of sufficient reason of becoming.)

(27) Matter, as that which is movable in space, makes phoronomy possible.

(28) The simple element in phoronomy is the atom.

224. FIRST BOOK. CHAPTER IV.

NOTES TO THE ANNEXED TABLE.

(i) To No. 4 of Matter.

The essence of matter is acting, it is acting itself, in the abstract, thus acting in general apart from all difference of the kind of action : it is through and through causality. On this account it is itself, as regards its existence, not subject to the law of causality, and thus has neither come into being nor passes away, for otherwise the law of causality would be applied to itself.

Since now causality is known to us a priori, the conception of matter, as the indestructible basis of all that exists, can so far take its place in the knowledge we possess a priori, inasmuch as it is only the realisation of an a priori form of our knowledge.

For as soon as we see anything that acts or is causally efficient it presents itself to ipso as material, and conversely anything material presents itself as necessarily active or causally efficient. They are in fact interchangeable conceptions.

Therefore the word "actual " is used as synonymous with " material ; " and also the Greek kot' ertpyeuw, in opposition to Kara Svrafiw, reveals the same source, for tvepytia. signifies action in general; so also with actu in opposition to po> tentia, and the English "actually" for "vrirklich.

What is called spaceoccupation, or impenetrability, and regarded as the essential predicate of body {i.e. of what is material), is merely that kind of action which belongs te all bodies without exception, the mechanical.

It is this universality alone, by virtue of which it belongs to the conception of body, and follows a prion from this conception, and therefore cannot be thought away from it without doing away with the conception itself — it is this, I say, that distinguishes it from any other kind of action, such as that of electricity or chemistry, or light or heat.

Kant has very accurately analysed this space-occupation of the mechanical mode of activity into repulsive and attractive force, just as a given mechanical force is analysed into two others by means of the parallelogram of forces. But this is really only the thoughtful analysis of the phenomenon into its two constituent parts.

The two forces in conjunction exhibit the body within its own limits, that is, in a definite volume, while the one alone would diffuse it into infinity, and the other alone would contract it to a point. Notwithstanding this reciprocal balancing or neutralisation, the body still acts upon other bodies which contest its space with the first force, repelling them, and with the other force, in gravitation, attracting all bodies in general.

So that the two forces are not extinguished in their product, as, for instance, two equal forces acting in different directions, or + E and - E, or oxygen and hydrogen in water. That impenetrability and gravity really exactly coincide is shown by their empirical inseparableness. in that the one never appears without the other, although we can separate them in thought.

I must not, however, omit to mention that the doctrine of Kant referred to, which forms the fundamental thought of the second part of his "Metaphysical First Principles of Natural Science," thus of the Dynamics, was distinctly and fully expounded before Kant by Priestley, in his exoafl^B "Disquisitions on Matter and Spirit," § i and 2, a book which appearedp. 225 in 1777, and the second edition in 1782, while Kant's work was published in 1786. Unconscious recollection may certainly be assumed in the case of subsidiary thoughts, flashes of wit, comparisons, &c, but not in the case of the principal and fundamental thought. Shall we then believe that Kant silently appropriated such important thoughts of anoiher man? and this from a book which at that time was new ? Or that this book was unknown to him, and that the same thoughts sprang up in two minds within a short time? The explanation, also, which Kant gives, in the "Metaphysical First Principles of Natural Science " (first edition, p. 88 ; Rosenkranz's edition, p. 384), of the real difference between fluids and solids, is in substance already to be found in Kaspar Freidr. "Wolff's "Theory of Generation," Berlin 1764, p. 132. But what are we to say if we find Kant's most important and brilliant doctrine, that of the ideality of space and the merely phenomenal existence of the corporeal world, already expressed by Maupertuis thirty years earlier ? This will be found more fully referred to in Frauenstadt's letters on my philosophy, Letter 14. Maupertuis expresses this paradoxical doctrine so decidedly, and yet without adducing any proof of it, that one must suppose that he also took it from somewhere else.