Marsilio Ficino’s Platonic Theology, Volume I

19If even a light breeze stirs the dust, and wind enclosed within the entrails of the earth shakes mountains, will you marvel that sublime souls turn the most subtle bodies with the slightest command? This is especially so because they move those bodies about their natural axis and within their proper circuit, and because the bodies themselves are more inclined by natural instinct toward such motion than an earthly body is toward descent when our soul guides its body down a slope. Heaven's body is disposed with such perfect balance and ease toward any position about the center as elemental matter is toward any form—indeed, far more so. Thus, as efficacy in moving belongs to soul, so readiness to be moved belongs to body. Since body is made by actuality, exists in actuality, and is directed toward actuality, its nature is to be exercised continually through its forms. And because both its substance and quality are divisible, whatever it does or undergoes must be done or undergone in a divisible manner—that is, through motion.

20The motion of the heavens and its variety contribute to generation and to the diversity of things that are generated. This motion adorns heaven with changing configurations and transmits the heavenly powers more forcefully into the elements. It moves the elements and compels them to mingle with one another in many ways, while by a certain alternation it equally illumines and nourishes their globe on every side. Moreover, the matter of the world cannot possess at once either all the configurations in heaven or all the forms beneath heaven, since many are contrary to one another. Yet everywhere it desires them all as perfections of its nature. It is therefore made prone to everlasting motion, so that what it cannot attain in a state of rest it may at least attain in some measure through succession. But why do the spheres revolve chiefly in a circle? Although I have just indicated the reason, let us begin again from a higher principle.