Marsilio Ficino’s Platonic Theology, Volume I

21God is a single circle: he is from himself and, like a circle, returns into himself, since outside himself he has neither the source of his being nor its end, but begins in himself and ends in himself. An angel is a double circle: first, because it returns to the source from which it flowed, when it understands and loves its author; and second, because it contemplates itself. Soul traces a threefold circuit: it looks toward God, considers itself, descends from causes to their effects, and ascends again from effects to causes. If these three movers of heaven describe their own circuits, what prevents them from carrying heaven itself around in a circuit? Since heaven imitates the higher causes in its figure and substance, why should it not imitate them also in motion and activity? Heaven lies beneath a mobile soul, and from this its motion begins. As soon as one part of heaven begins to move, the continuity of the whole makes it draw another part with it and drive another before it, while the parts necessarily turn back upon one another in a circle.

22Heaven cannot stand still, since its soul knows no rest; yet neither does it wish to leave its natural place. Thus it revolves about the same point and, though always moving, remains in the same place; for earth, which lies farthest from it, is always motionless. Whatever moves forever must return to the same point, since no corporeal expanse is infinite. Plato says further in the *Statesman*: Only the most divine of all things can possess a condition wholly exempt from change.

23The world, however, because it is body and has already fallen away from the dignity of divine things, cannot be wholly immutable. Yet because it is nearest to the divine, it was fitting that it should move with a circular motion. Such motion revolves in the same place, around the same point, along the same course, with even and unbroken continuity, and therefore departs as little as possible from stability of place. So far Plato. Add that, among all forms of motion, motion in place alone, since it is as though external, is not compelled to alter the natural substance or quality of its subject. Likewise, among local motions, circular motion alone does not change place and may therefore be said to be motion that is almost no motion at all.