On the other side, the division of the circles from the centre to the extremities, being harmoniously appropriated to the essence of the soul, the one knows existing things and establishes harmony between them, because it is itself composed of harmonious elements. The circle of what is changeable, engenders opinion by its regular movements; but the circle of that which is always the same produces knowledge.
XLI. Plato lays down two primary causes or principles of all things, God and matter, which he also calls mind, and the cause. And he defines matter as something without shape and without limitation, and says that from it all concretions arise. He affirms also that as it was moving about at random, it was brought by God into one settled place, as God thought order better than disorder; and that this nature is divided into four elements, fire, water, air, and earth, of which the world itself and everything in it was made. But he says that the earth is the only thing that is unchangeable, as he considers the cause to be the difference of the figures of which it is composed; for he says that the figures of the others are homogeneous; for that they are all composed equally of scalene triangles. The figure of the earth, however, is peculiar to itself; for the element of fire is a pyramid; of air, an octagon; of water, an eicosagon; and of the earth, a cube; owing to which these things cannot be changed into earth, nor earth into them. He teaches also that these elements are not separated so as to occupy each a peculiar and distinct place; for the spherical motion collects and compresses all the small things towards the centre, and the small things separate the great ones, on which account the species, as they change, do also change their positions.
Moreover he asserts that the world is one, and has been produced, since it has been made by God, in such a manner as to be an object of sensation. And he considers it endowed with life, because that which is so endowed,