Marsilio Ficino’s Platonic Theology, Volume I

17Mind itself does not necessarily depend on a body in its understanding and will; it naturally abstracts forms, occupies itself with forms so abstracted, and advances through rest rather than motion. It is therefore free by nature from body and motion. Hence it accords better with its nature to live apart from body and motion than to live in body and motion. Many minds nevertheless lead a mobile life in bodies. All the more, then—and in far greater numbers—do minds live an immobile life without bodies. Who would deny that it accords better with the nature of the incorporeal kind for an incorporeal substance to exist outside a body than within one, and therefore that more of its species should be separate from body than conjoined to it? For whatever is more natural to any kind is found in it in the greatest abundance.

18Such, indeed, are angels: if they move the bodies of the world, they themselves are in no way moved when those bodies move. Souls, by contrast, are themselves carried along while they convey bodies from place to place. A mover that ranges together with a moving body does not preserve an everlasting, stable course and order of motion unless an immobile mover presides over it. The perpetual order of the world's revolution therefore testifies that there are immobile movers above souls. Because the elements consist of fluctuating matter and constantly affect one another, they would preserve no order of themselves unless they were ruled by the supremely ordered law of celestial motion. And since heaven is of itself perpetually mobile and therefore needy, the stable order in its motion does not come from itself but from a higher mover, wholly immobile and indivisible. For among things so diverse and mobile, no stable union endures unless it comes from a supremely stable and unified pivot, which is referred in the end to unity itself and to stability. Indeed, as one mobile thing stands in relation to another, so one mover stands in relation to another. Thus an element, which is moved changeably, is related to heaven, which is moved stably; in the same way heaven's mobile and varying mover is related to a stable and unified mover; and what is stable and unified is finally reduced to stability and unity themselves.