THREE:In like manner, Lucretius rejects the theory that living bodies are made up of the four elements, much as he admires110 its author, Empedocles. It seemed to him a blind confusion of the inorganic with the organic, the complex harmonies of life needing a much more subtle explanation than was afforded by such a crude intermixture of warring principles. If the theory of Anaxagoras fares no better in his hands, it is for the converse reason. He looks on it as an attempt to carry back purely vital phenomena into the inorganic world, to read into the ultimate molecules of matter what no analysis can make them yieldthat is, something with properties like those of the tissues out of which animal bodies are composed.Out of this eternal unchanging divine substance, which he calls aether, are formed the heavenly bodies and the transparent spheres containing them. But there is something beyond it of an even higher and purer nature. Aristotle proves, with great subtlety, from his fundamental assumptions, that the movement of an extended substance cannot be self-caused. He also proves that motion must be absolutely continuous and without a beginning. We have, therefore, no choice but to accept the existence of an unextended, immaterial, eternal, and infinite Power on which the whole cosmos depends.