That this undecomposable mode of consciousness into which all other modes may be decomposed, cannot be itself the Power manifested to us through phenomena, has been already proved (§ 18). We saw that to assume an identity of nature between the cause of changes as it absolutely exists, and that cause of change of which we are conscious in our own muscular efforts, betrays us into alternative impossibilities of thought. Force, as we know it, can be regarded only as a certain conditioned effect of the Unconditioned Cause—as the relative reality indicating to us an Absolute Reality by which it is immediately produced. And here, indeed, we see even more clearly than before, how inevitable is that transfigured realism to which sceptical criticism finally brings us round. Getting rid of all complications, and contemplating pure Force, we are irresistibly compelled by the relativity of our thought, to vaguely conceive some unknown force as the correlative of the known force. Conditioned effect and unconditioned cause, are here presented in their primordial relation as two sides of the same change; of which we are obliged to regard the conditioned and the unconditioned sides as equally real: the only difference being that the reality of the one is made relative by the imposition of the forms and limits of our consciousness, while the reality of the other, in the absence of those forms and limits, remains absolute. Thus much respecting the nature of our ultimate scientific ideas. Before proceeding to our general inquiry concerning the causes of Evolution, we have still to consider certain ultimate scientific truths. ----- Footnote 11: For the psychological conclusions briefly set forth in this and the three sections following it, the justification will be found in the writer’s _Principles of Psychology_. CHAPTER VI. THE INDESTRUCTIBILITY OF MATTER. § 66. Not because the truth is unfamiliar, is it needful here to say something concerning the indestructibility of Matter; but partly because the symmetry of our argument demands the enunciation of this truth, and partly because the evidence on which it is accepted requires examination. Could it be shown, or could it with any rationality be even supposed, that Matter, either in its aggregates or in its units, ever became non-existent, there would be an end to the inquiry on which we are now setting out. Evolution, considered as a re-arrangement of parts, could not be scientifically explained, if, during its course, any of the parts might arise out of nothing or might lapse into nothing. The question would no longer be one comprehending only the forces and motions by which the re-arrangement is effected; but would involve an incalculable element, and would hence be insoluble. Clearly, therefore, the indestructibility of Matter is an indispensable axiom.