"When... Heraclitus names the world an ever-living fire that... extinguishes itself and again kindles itself, when... all is exchanged for fire and fire for all... he can only understand by this that fire, this restless, all-consuming, all-transmuting, and equally (in heat) all-vivifying element, represents the constant force of this eternal alteration and transformation, the notion of life, in the most vivid and energetic manner. ...the means of which the power of motion that is precedent to all matter avails itself for the production of the living process of things. Heraclitus... explains the multiplicity of things... [fire] condenses itself into material elements, first air, then water, then earth. ...These two processes of extinction and ignition... alternate... in perpetual rotation with each other and... in stated periods the world resolves itself into the primal fire, in order to re-create itself out of it again. ...[F]ire is to him... the principle of movement, of physical as of spiritual vitality; the soul itself is a fiery vapour; its power and perfection depend on its being pure from all grosser and duller elements."