Marsilio Ficino’s Platonic Theology, Volume II

Fourth argument: a body is composed of matter and form.

1Every natural body is composed of matter and form. An animal is a natural body. It therefore has matter and form within it. Yet it is made up of soul and body. Body, however, is not a natural form, because a natural form is the form of something and exists in something as in a subject that it forms. But body is the form of nothing and does not exist in something as in a subject, but in a place. It remains that soul is the form, chiefly because it is the proper and inward principle of operations and motions. Indeed, it is also the animal's principle of being. All this belongs to form. Soul, therefore, is form. If the soul itself were also a body, another form would still be needed, belonging both to soul and body, by which the two together would be called one animal. We would more properly call that other form soul. For through soul, as through form, the body which before was living in a certain potency becomes living in act and an animal in act. Soul, then, is form alone. This is especially so because, if it had two parts, namely matter and form, three absurdities would follow. First, it would not form the body according to its whole self, because it would not form it through the part of itself that is matter.

2Yet a proper form must, through its entire essence, perfect the whole of its proper matter. Second, the part of soul called form would be the perfection of two matters of the same kind, which nature does not permit, just as it does not permit two forms of the same kind to form the same matter. Third, soul would be changed into these lower bodies, and they in turn into soul, if it possessed matter in common with them.