Marsilio Ficino’s Platonic Theology, Volume I

8For then he would be God himself, not an angel. Yet neither does he lose both, lest God’s nearest and first work become utterly unlike its maker. What, then? Will he retain unity alone, or stability? He cannot possess unity alone without stability, for unity itself is wholly immovable. He will therefore retain stability but fall away from simple unity, so that angel is an immovable multiplicity.

9Nor do we assign multiplicity to the angel without cause. For if he were perfect and absolutely one, his power would be supreme and unlimited, since power consists in unity. God alone himself is unlimited power. Now, if it is proper to body to receive and undergo, but proper to incorporeal nature to give and act, then in corporeal nature there is what is called potency—namely, as the theologians say, receptive and passive potency—while in incorporeal nature there is actuality, that is, efficacy for action. Thus quality, because it is in itself incorporeal in a certain sense, possesses some power of acting and is therefore also called actuality. But because it is received and divided in matter, and thereby becomes in a certain sense corporeal, it is not pure actuality but is tainted by the passivity of body.