The important matter now would be to indicate the relation of atoms to sensuous appearance, to allow essence to pass over into the negative: but here Epicurus rambles amidst the indeterminate which expresses nothing; for we perceive in him, as in the other physicists, nothing but an unconscious medley of abstract ideas and realities. All particular forms, all objects, light, colour, &c., the soul itself even, are nothing but a certain arrangement of these atoms. This is what Locke also said, and even now Physical Science declares that the basis of things is found in molecules, which are arranged in a certain manner in space. But these are empty words, and a crystal, for instance, is not a certain arrangement of parts, which gives this figure. It is thus not worth while to deal with this relation of atoms; for it is an altogether formal way of speaking, as when Epicurus again concedes that figure and magnitude, in so far as pertaining to atoms, are something different from what they are as they appear in things. The two are not altogether unlike; the one, implicit magnitude, has something in common with apparent magnitude. The latter is transitory, variable; the former has no interrupted parts,[156] that is, nothing negative. But the determination of the atoms, as originally formed in this or that fashion, and having original magnitude of such and such a kind, is a purely arbitrary invention. That interruption, which we regarded above (p. 288) as the other side to atoms, or as vacuum, is the principle of movement: for the movement of thought is also like this and has interruptions. Thought in man is the very same as atoms and vacuum are in things, namely their inward essence; that is to say, atoms and vacuum belong to the movement of thought, or exist for this in the same way as things are in their essential nature. The movement of thinking is thus the province of the atoms of the soul; so that there takes place simultaneously therein an interruption of the inward flow of atoms from without. There is therefore nothing further to be seen in this than the general principle of the positive and negative, so that even thought is affected by a negative principle, the moment of interruption. This principle of the Epicurean system, further applied to the difference in things, is the most arbitrary and therefore the most wearisome that can be imagined. Besides their different figures, atoms have also, as the fundamental mode in which they are affected, a difference of movement, caused by their weight; but this movement to some extent deviates from the straight line in its direction. That is to say, Epicurus ascribes to atoms a curvilinear movement, in order that they may impinge on one another and so on.[157] In this way there arise particular accumulations and configurations; and these are things.