Marsilio Ficino’s Platonic Theology, Volume II

Ninth argument. A bodily constitution is an accidental form.

1A bodily constitution is a certain nature made up in some fashion from contrary qualities and occupying a kind of middle position among them. From this it follows that it cannot be a substantial form, for it does not subsist in itself but in the body that is the subject of those contrary qualities. Because the qualities conflict with one another, they do not receive one another; rather, matter receives them, and when they are mingled with one another they generate a constitution. This constitution, therefore, is not a substance both for the reason I have given and because it has something contrary to it—namely, an excess of some foreign quality that disrupts its composition. Moreover, it admits of more and less: the nature, power, and operation of a constitution are intensified and diminished. Substance, however, neither has a contrary proper to itself—since the very contrariety of things belongs to a genus other than substance, namely the genus of quality—nor is substance in its own nature intensified toward more or diminished toward less, as though this or that substance, once it is a substance, were now more and now less what it is; that is, as though this stone were more or less a stone than that one. Since, therefore, a constitution is not a substance, if the soul is a substance, it is not a constitution.