Marsilio Ficino’s Platonic Theology, Volume II

18These courses of reasoning are a kind of motion proper to the nature of the soul, as we have explained elsewhere. They do not belong to God or the angels, who possess and see all things at once; nor to bodies, which do nothing of themselves; nor to corporeal forms, which are not moved toward incorporeal things. Yet courses of reasoning of this kind, by leading us to divine things, raise us above the nature of body. Neither body nor anything else can of itself be carried above its own nature. Such revolutions, therefore, although alien to bodies, are nevertheless present in the soul and testify that the soul can be neither a body nor a form divided throughout a body. This is especially so because in these revolutions the soul is moved of itself—that is, by its own nature and power—and therefore moves itself, which body cannot do.

19Moreover, exemplars of corporeal motions appear in the soul. There is an exemplar of generation when it cleaves to divine things; of corruption when it cleaves to mortal things; of increase when it recollects; of decrease when it forgets; of alteration when it varies the succession of its affections; of condensation when it suddenly beholds something or gathers itself together; of rarefaction when it ranges abroad or is distracted among many things; and of progression in a straight line when it first reaches external things. There is an exemplar of circular motion when, within things themselves, it resolves an effect into its cause and derives the effect from the cause, or when it turns back to contemplate itself. Again it seems to move in a straight line when it descends toward body and sense; obliquely when it turns back upon itself or toward an angel; in a circle when it turns toward God, its beginning and end; upward toward universals; downward toward particulars; to the right and left toward the opposed differences of a kind; and finally forward and backward when it turns toward natural causes or effects.