Dive into any moment of the rich cosmogenesis of Plato’s Timaeus and you may find yourself swimming through celestial waters rife with symbolic imagery that unfold into a myriad display of applicable meaning. When the Same, the Different, and Being are brought together in a dynamic primordial mixture, the Soul of the World is born, a Soul that echoes and is echoed by the physical cosmos that is composed of fire, air, earth, and water. The shape and motion of the World Soul mirrors the shape and motion of the physical world, which can primarily be seen in the movement of the spheres of heaven, the motion of the planets and fixed stars around their earthly axis. When the Demiurge crafts the immortal spark present in every mortal human—the human soul—the Demiurge draws from the mixture of the Same, the Different, and Being of which the World Soul was composed. If the World Soul mirrors the motion of the cosmos, does this indicate the human soul does as well, as it too is made from the same, though slightly altered, substance as the first Soul? Additionally, can the illustration of Timaeus’ geocentric cosmos still carry symbolic meaning when read from a heliocentric perspective?
The substance of the World Soul is first divided into geometrical portions that are brought harmoniously back together to create the three-dimensional structure of the cosmos as we perceive it. This compound is then split in two and rejoined at the centers, before each is bent back upon itself and rejoined again to create two concentric spheres. This process of dividing and rejoining, over and over again to create the structure of Soul, mirrors the ingredients that were brought together to form the Soul in the first place: the Same, the Different, and Being. The Different brings division, the Same reunites that which has been divided, and thus they continue to form Being; it is a dialectic of creation. Once this substance has been shaped into the two spheres, the Demiurge “decreed that the outer movement should be the movement of the Same, while the inner one should be that of the Different.” The sphere of the Same remains whole, while the sphere of the Different is once again divided into “seven unequal circles.” The Demiurge “set the circles to go in contrary directions: three to go at the same speed, and the other four to go at speeds different from both each other’s and that of the other three.” We see here the different motions of the planetary orbits, perceived during Plato’s time to revolve around the fixed sphere of the Earth: “The Earth he devised to be our nurturer, and because it winds around the axis that stretches throughout the universe, also to be the maker and guardian of the day and night.” The sphere of the Same is the outermost circle of the fixed stars, which moves about the Earth to the right, while the Earth itself was understood to rotate on its axis causing day and night.
Timaeus’ account of the creation of the ensouled cosmos reflects the most sophisticated astronomical knowledge of his time, including the observations that the pathways traced by the seven planets were erratically wandering, something seemingly contrary to the belief that the heavens were a “moving image of eternity.” The Demiurge creates the cosmos as a begotten model of the eternal Forms, yet because it is an imitation and not the Forms themselves the cosmos is not itself eternal. Plato describes that which is eternal as “always changeless and motionless” whereas the ordered cosmos is always in motion. As Plato writes, it is the nature of the Forms on which the cosmos is modeled
to be eternal, but it isn’t possible to bestow eternity fully upon anything that is begotten. And so [the Demiurge] began to think of making a moving image of eternity: at the same time as he brought order to the universe, he would make an eternal image, moving according to number, of eternity remaining in unity. This number, of course, is what we now call “time.”
The planets, and the gods embodying them, “came to be in order to set limits to and stand guard over the numbers of time.” The differing speeds of their motions determine the course and divisions of time: the Sun’s “chief works would be to shine upon the whole universe and to bestow upon all those living things appropriately endowed and taught by the revolution of the Same and the uniform, a share in number”; the Moon inscribes the course of a month, the Sun the course of a year. The spheres of the Different divide into the differentiations of time the sempiternal quality of the fixed celestial sphere of the Same.
Timaeus observes that few people have taken note of the temporal length of the other planetary orbits. He says, “Nobody has given them names or investigated their numerical measurements relative to each other. And so people are all but ignorant of the fact that time really is the wanderings of these bodies, bewilderingly numerous as they are and astonishingly variegated.” Was it really the case that few people in Plato’s time knew that the orbit of Mars was two years, Jupiter’s twelve, or Saturn’s twenty-nine? Or is Plato pointing toward some other ignorance in relation to the wandering motion of the planets? Timaeus goes on to say directly after this statement:
It is nonetheless possible, however, to discern that the perfect number of time brings to completion the perfect year at that moment when the relative speeds of all eight periods have been completed together and, measured by the circle of the Same that moves uniformly, have achieved their consummation. This, then, is how as well as why those stars were begotten which, on their way through the universe, would have turnings. The purpose was to make this living thing as like as possible to that perfect and intelligible Living Thing, by way of imitating its sempiternity.
The ordered cosmos is an imitation of the eternal Forms, but “the resemblance still fell short” nonetheless of the perfect model. The wanderings of the planets are an indication of that imperfect imitation. Yet in the previous passage Plato seems to be indicating a time in which the eight spheres will all be aligned, the ‘perfect number of time’ that will complete the ‘perfect year’ and elevate the cosmos to the level of perfection of the eternal Forms.
How is this passage to be read from a heliocentric perspective, from a world view shaped by the Copernican Revolution? Is the consummation of that ‘perfect year’ reflective of a time when the wanderings of the planets are no longer erratic, but rather are in continuous geometrical motion, a true ‘moving image of eternity’?
The Soul of the World contains within it these continual motions of the Same and the Different, as it appears to strive for the perfection of the eternal Forms. This striving towards perfection, according to Plato, is also the task of the philosopher as he or she moves towards Wisdom. Indeed, the motions of the cosmos and the motions of the human soul appear to be parallel as they continue to move in their variegated orbits towards the eternal Forms, towards Goodness, Beauty, and Truth, towards Wisdom. If the philosopher is truly to be a lover of Wisdom he or she must remain as that: a lover and not possessor of Wisdom. So too the cosmos cannot possess the Forms of which it is a reflection; instead it is in a loving dance with eternity, the motions we witness across the sky with the passing of each night. Yet both the World Soul of the cosmos and the soul of the philosopher may still strive for that ‘perfect year,’ the consummation of all motion into one moment when eternity and time, the soul and Wisdom, are united.
Plato. Plato: Complete Works. Edited by John M. Cooper. Indianapolis, IN: Hackett, 1997.
 Plato, Timaeus, trans. Donald J. Zeyl, in Plato: Complete Works, ed. John M. Cooper (Indianapolis, IN: Hackett, 1997), 1240, 36c.
 Plato, Timaeus, 1240, 36d.
 Ibid, 1244, 40c.
 Ibid, 1241, 37d.
 Plato, Timaeus, 1241, 38a.
 Ibid, 1241, 37d.
 Ibid, 1242, 38c.
 Ibid, 1242, 39b.
 Plato, Timaeus, 1243, 39c-39d.
 Ibid, 1243, 39d-39e.
 Ibid, 1243, 39e.