equently it is impossible for
any substantial form to receive "more" or "less." Nor is it less
impossible for anything to be a medium between substance and accident.

Therefore we must say, in accordance with the Philosopher (De Gener.
i, 10), that the forms of the elements remain in the mixed body, not
actually but virtually. For the proper qualities of the elements
remain, though modified; and in them is the power of the elementary
forms. This quality of the mixture is the proper disposition for the
substantial form of the mixed body; for instance, the form of a stone,
or of any sort of soul.
_______________________

FIFTH ARTICLE [I, Q. 76, Art. 5]

Whether the Intellectual Soul Is Properly United to Such a Body?

Objection 1: It would seem that the intellectual soul is improperly
united to such a body. For matter must be proportionate to the form.
But the intellectual soul is incorruptible. Therefore it is not
properly united to a corruptible body.

Obj. 2: Further, the intellectual soul is a perfectly immaterial
form; a proof whereof is its operation in which corporeal matter does
not share. But the more subtle is the body, the less has it of matter.
Therefore the soul should be united to a most subtle body, to fire,
for instance, and not to a mixed body, still less to a terrestrial
body.

Obj. 3: Further, since the form is the principle of the species, one
form cannot produce a variety of species. But the intellectual soul
is one form. Therefore, it should not be united to a body which is
composed of parts belonging to various species.

Obj. 4: Further, what is susceptible of a more perfect form should
itself be more perfect. But the intellectual soul is the most perfect
of souls. Therefore since the bodies of other animals are naturally
provided with a covering, for instance, with hair instead of clothes,
and hoofs instead of shoes; and are, moreover, naturally provided
with arms, as claws, teeth, and horns; it seems that the intellectual
soul should not have been united to a body which is imperfect as
being deprived of the above means of protection.

_On the contrary,_ The Philosopher says (De Anima ii, 1), that "the
soul is the act of a physical organic body having life potentially."

_I answer that,_ Since the form is not for the matter, but rather the
matter for the form, we must gather from the form the reason why the
matter is such as it is; and not conversely. Now the intellectual
soul, as we h