Helmholtz's proof established mathematically what Kant had already, by direct insight, advanced as an À priori fundamental axiom: that in any given system [pg 233] the sum of energy can neither increase (impossibility of a perpetuum mobile) nor diminish (there is no disappearance of energy, but only transformation into another form). But even the vitalist had no need to deny this proposition. The “energy” which is required for the work of directing, setting agoing, changing and rearranging the chemico-physical processes in the body, and bringing about the effective reactions to stimuli which result in “development,” “transmission,” “regeneration,” and so on—if indeed any energy is required—of course could not come “from within” as a spontaneous increase of the existing sum of energy—that would, indeed, be a magical becoming out of nothing!—but must naturally be thought of as coming “from without.” The appeal to the law of the conservation of energy is therefore in itself irrelevant; but it conceals behind it an assertion of a totally different kind, namely, that in relation to physico-chemical sequences there can be no “without,” nothing transcending them—an assertion which Helmholtz's arguments cannot and were never intended to establish. But before any definite attitude to this newly imported assertion could be taken up, it would require to be distinctly defined, and that would lead us at once into all the depths of epistemological discussion. Here, therefore, we can only say so much: If this assertion is accepted it is well to see where it carries us; namely, back to the first-described naÏve standpoint, which, without critical scruples, quite seriously accepts the world as it appears to it for the [pg 234] reality, and quite seriously speaks of an infinity lying in time behind us—and therefore come to an end—and is not in the least disturbed from its “dogmatic slumber” by this or any of the other great antinomies of our conception of the universe. And it remains, too, for this standpoint to come to terms with the fact that, in voluntary actions, of which we have the most direct knowledge, we have through our will the power of intervention in the physico-chemical nexus of our bodily energies—a fact which implies the existence of a “without,” from which interpolations or influences may flow into the physico-chemical system, even if there be none in regard to the domain of “vital” phenomena. And we should require to find out through what parallelistic or abruptly idealistic system the “without” was done away with in this case. For if a transcendental basis, or reverse side, or cause of things, be admitted—even if only in the form of our materialistic popular metaphysics (the “substance” of Haeckel's “world-riddle”)—then a “without,” from which primarily the cosmic system with its constant sum of matter and energy is explained, is also admitted, and it is difficult to see why it should have exhausted itself in this single effort.