Marsilio Ficino’s Platonic Theology, Volume II

Eighth argument. A form in the mind is universal; such a form cannot exist in a body.

1A body, and a form extended throughout a body, are so material, if I may speak in this way, and so bound to a particular place and time that they possess no universal power. For the nearer a thing comes to bodily matter, the narrower it is; the farther it withdraws, the more ample it becomes. Therefore, if the intellect were a body or a form diffused throughout one, every form it received—even if universal in itself—would at least become wholly particular and material within it. Forms in a subject bound by the passions of matter retain no power to represent anything universal. Whatever the intellect thought, then, it would think through a material form bound by singular conditions. Since the activity of every thing follows the form of the thing acting, an intellect operating through such a form—that is, thinking through it—would operate only in a singular manner. The work is always of the same character as the operation. Thus an intellect thinking singularly would think only singular things and would know nothing common or universal. It would turn over within itself one individual human being, such as Socrates or Plato, but by no means the human nature equally common to them both. Nor would it establish in morals and the arts a universal rule applying to many instances, or ever frame a law governing the actions of many human beings.

2If the mind, even without deliberate choice or habitual practice, brings forth universal forms within itself day after day, it follows that it is their natural source and their natural receptacle. Forms of this kind are in no way bound to any matter as its exclusive property. The mind therefore is not bound to matter and will never be corrupted, for corruption arises from the snares of matter.