[These courses were encased in the head, which, like the universe, is in the form of a sphere. The body, with its four limbs, is the vehicle of the head; it moves forward because the front part of us is the more honourable. In the front part of the head the face was inserted, and in the face, eyes. Sight arises thus:—The light from the eyes and the light of day, which is akin to it, combine; and when they meet with the light from an object, all three form one body, which transmits to the soul the motions of the object. In the case of reflections in plane mirrors, the transposition of right and left is due to the fact that the light from the eye and the object meet in an unusual manner. In a concavemirror, if held horizontally, there is no transposition; but if it be held vertically.] First, then, the gods, imitating the spherical shape of the universe, enclosed the two divine courses in a spherical body,