 The first of the main sections of the discourse explains the existence of the universe and some of its most general features teleologically. The universe exists and manifests goodness because it is the handiwork of a supremely good, ungrudging Craftsman, who brought order to an initially disorderly state of affairs. It is a living thing (zô[i]on, also translatable as “animal”), because it is better for it to possess intelligence than to lack it, and the acquisition of intelligence requires the acquisition of soul. It is complete, and thus it includes within itself all the species of living things as its parts. It is unique, because its model is unique; the uniqueness of the model follows from its completeness. The world’s body is composed of fire (for visibility) and earth (for tangibility), but these so-called elements require the mediation of air and water in a progression of proportion to bind them together into a unified, concordant whole. The shape of the universe’s body—a sphere—and the characteristics it possesses or lacks are all explained in terms of their various purposes. The composition of the world’s soul out of a harmonically proportionate series of portions of a mixture of both divisible and indivisible Sameness, Difference and Being, and the division of these portions into two intersecting circles (called the circle of the Same and of the Different) explain the cognitive powers of the soul in relation to the different types of objects of cognition: those that are and those that become. When joined with the world’s body, they also explain the cosmological organization of the universe. The heavenly bodies are divine and move in their various orbits to serve as markers of time: the fixed stars to mark a day/night, the moon to mark the (lunar) month and the sun to mark the year. Time itself came into being together with these celestial movements as an “image of  eternity.”[4]  Individual souls are made up of the residue (and an inferior grade) of the soul stuff of the universe, and are eventually embodied in physical bodies. This embodiment throws the previously regular motions of the soul into confusion as the soul is subjected to the forceful disturbances of internal bodily processes as well as the impact of external bodies upon it, particularly in sense experience. These disturbances gravely impair the soul’s cognitive functioning; only with appropriate nurture and education can its original motions be reestablished and proper cognitive functioning be restored. The body and its parts were designed to support that functioning, and Timaeus takes the design of the eyes and the mechanics of vision as an important case in point.