Marsilio Ficino’s Platonic Theology, Volume I

The souls of the spheres move the spheres according to the law of fate, and move them in a circle because they are themselves circles.

1In what manner do the heavenly souls move their spheres? Surely—as the Platonists hold—in the same way that your soul moves your body through appetite, an appetite which there too is aroused by thought.

2There, thought itself springs from the fated law of that soul. Hence Plato says in the *Statesman*: "Fate and an inborn desire move heaven." He seems to have received this from Zoroaster, from whom all the wisdom of the ancient theologians flowed. For when Zoroaster speaks of heaven, he says, "ἀϊδίῳ βουλῇ φέρεται, ἀεὶ τρέχει ἔργῳ ἀνάγκης"—that is, "It is borne by an everlasting will; it runs always under necessity's working." We shall understand this clearly if we consider the order of things as follows.

3There is something said to be above every whole, and something that lies beneath every whole. What is said to be above every whole is God, who cannot properly be a whole, because he is the most simple unity, above number. These individual bodies lie beneath every whole. Between that which is above every whole and that which lies beneath every whole, therefore, there must be something intermediate.

4That intermediate is the Whole itself, the complete sum of all things.

5There will, however, be a threefold Whole—or rather, three kinds of whole. The first whole depends immediately upon the very unity of God. Since it is most like that unity, it must therefore be one to the greatest extent possible. A thing can be one in three ways: in essence, in point, and in moment. It is one in essence when it is a single substance, not composed of several substances; one in point when it is not dispersed into many parts and thereby forced to be divided among many points of space; and one in moment when it acquires in the blink of an eye whatever it can ever possess, and does not vary through the successive moments of time.