somewhere or other, as well as their having been brought together somehow or other, precisely because of the transcendental nature of the principle of the permanence of Substance. In my Critique of Kantian Philosophy,[65] I have shown at length, that _Substance_ is but another word for _Matter_, the conception of substance not being realisable excepting in _Matter_, and therefore deriving its origin from _Matter_, and I have also specially pointed out how that conception was formed solely to serve a surreptitious purpose. Like many other equally certain truths, this eternity of Matter (called the permanence of substance) is forbidden fruit for professors of philosophy; so they slip past it with a bashful, sidelong glance. [65] "Die Welt a. W. u. V." vol. i. p. 550 of 2nd, and 580 of 3rd edition. By the endless chain of causes and effects which directs all _changes_ but never extends beyond them, two existing things remain untouched, precisely because of the limited range of its action: on the one hand, _Matter_, as we have just shown; on the other hand, the primary _forces of Nature_. The first (matter) remains uninfluenced by the causal nexus, because it is _that which undergoes_ all changes, or _on which_ they take place; the second (the primary forces), because it is they alone _by which_ changes or effects become possible; for they alone give causality to causes. _i.e._ the faculty of operating, which the causes therefore hold as mere vassals a fief. Cause and effect are _changes_ connected together to necessary succession in Time; whereas the forces of Nature by means of which all causes operate, are exempt from all change; in this sense therefore they are outside Time, but precisely on that account they are always and everywhere in reserve, omnipresent and inexhaustible, ever ready to manifest themselves, as soon as an opportunity presents itself in the thread of causality. A _cause_, like its _effect_, is invariably something individual, a single change; whereas a force of Nature is something universal, unchangeable, present at all times and in all places. The attraction of a thread by amber, for instance, at the present moment, is an effect; its cause is the preceding friction and actual contact of the amber with the thread; and the _force of Nature_ which acts in, and presides over, the process, is Electricity. The explanation of this matter is to be found in my chief work,[66] and there I have shown in a long chain of causes and effects how the most heterogeneous natural forces successively come into play in them. By this explanation the difference between transitory phenomena and permanent forms of operation, becomes exceedingly clear; and as, moreover, a whole section (§ 26) is devoted to the question, it will be sufficient here to give a brief sketch of it. The _rule_, by which a force of Nature manifests itself in the chain of causes and effects--consequently the link which connects it with them--is the law of Nature.