Such therefore, being the animation of the world, or its participation of soul, Plato, as it is usual with him, beginning according to conversion from things that are last, first imparts soul to the middle, afterwards to the universe, and in the third place leaves something of soul external to the universe. For as he gave subsistence to body prior to soul, and to parts prior to wholes, thus also he imparts soul to the world, beginning from things that have an ultimate existence. When Plato therefore delivered the order of the plenitudes of the world according to progression, beginning supernally, he placed intellect in soul, and soul in body. But here where he delivers the order according to conversion, he first animates the middle, and afterwards the universe itself. For the river of vivification proceeds as far as to the centre; as the Chaldean oracles also assert, when speaking about the middle of the five centres, which from on high passes entirely to the opposite part, through the centre of the earth. For they say: “And another fifth middle fiery centre, where a life-bearing fire descends as far as to the material rivers.” Hence Plato beginning from those things in which animation ends, recurs to the whole vivification, and prior to this surveys the exempt power of the soul. We must not therefore place the ruling part of the soul in the centre; for this is exempt from the universe; but a certain power of it which guards the whole order of the world. For nothing else in the universe has so much the power of entirely subverting the whole of things, as the centre and the power of the centre, about which the universe with measured motion harmoniously revolves. Hence it appears to me that Plato divinely says that the demiurgus placed _soul_ and not _the soul_ in the middle of the universe. For these differ from each other, because the latter establishes the whole soul in the centre, but the former a certain power of it, and a different power in different parts.