Heraclitus has analyzed the principle of the becoming still more closely, in the propositions which he utters, to account for the origin of things, where he shows that all becoming must be conceived as the product of warring opposites, as the harmonious union of opposite determinations. Hence his two well-known propositions: “Strife is the father of things,” and “The One setting itself at variance with itself, harmonizes with itself, like the harmony of the bow and the viol.” “Unite,” so runs another of his sayings, “the whole and the not-whole, the coalescing and the not-coalescing, the harmonious and the discordant, and thus we have the one becoming from the all, and the all from the one.” 4. THE PRINCIPLE OF FIRE.—In what relation does the principle of fire, which is also ascribed to Heraclitus, stand to the principle of the becoming? Aristotle says that he took fire as his principle, in the same way that Thales took water, and Anaximenes took air. But it is clear we must not interpret this to mean that Heraclitus regarded fire as the original material or fundamental element of things, after the manner of the Ionics. If he ascribed reality only to the becoming, it is impossible that he should have set by the side of this becoming, yet another elemental matter as a fundamental substance. When, therefore, Heraclitus calls the world an ever-living fire, which in certain stages and certain degrees extinguishes and again enkindles itself, when he says that every thing can be exchanged for fire, and fire for every thing, just as we barter things for gold and gold for things, he can only mean thereby that fire represents the abiding power of this eternal transformation and transposition, in other words, the conception of life, in the most obvious and effective way. We might name fire, in the Heraclitic sense, the symbol or the manifestation of the becoming, but that it is also with him the substratum of movement, _i. e._ the means with which the power of movement, which is antecedent to all matter, serves it self in order to bring out the living process of things. In the same way Heraclitus goes on to explain the manifoldness of things, by affirming that they arise from certain hindrances and a partial extinction of this fire. The product of its extremest hindrance is the earth, and the other things lie intermediately between.