this operation as properly
belonging to him. Man must therefore derive his species from that
which is the principle of this operation. But the species of anything
is derived from its form. It follows therefore that the intellectual
principle is the proper form of man.

But we must observe that the nobler a form is, the more it rises above
corporeal matter, the less it is merged in matter, and the more it
excels matter by its power and its operation; hence we find that the
form of a mixed body has another operation not caused by its elemental
qualities. And the higher we advance in the nobility of forms, the
more we find that the power of the form excels the elementary matter;
as the vegetative soul excels the form of the metal, and the sensitive
soul excels the vegetative soul. Now the human soul is the highest and
noblest of forms. Wherefore it excels corporeal matter in its power by
the fact that it has an operation and a power in which corporeal
matter has no share whatever. This power is called the intellect.

It is well to remark that if anyone holds that the soul is composed of
matter and form, it would follow that in no way could the soul be the
form of the body. For since the form is an act, and matter is only in
potentiality, that which is composed of matter and form cannot be the
form of another by virtue of itself as a whole. But if it is a form by
virtue of some part of itself, then that part which is the form we
call the soul, and that of which it is the form we call the "primary
animate," as was said above (Q. 75, A. 5).

Reply Obj. 1: As the Philosopher says (Phys. ii, 2), the ultimate
natural form to which the consideration of the natural philosopher is
directed is indeed separate; yet it exists in matter. He proves this
from the fact that "man and the sun generate man from matter." It is
separate indeed according to its intellectual power, because the
intellectual power does not belong to a corporeal organ, as the power
of seeing is the act of the eye; for understanding is an act which
cannot be performed by a corporeal organ, like the act of seeing. But
it exists in matter so far as the soul itself, to which this power
belongs, is the form of the body, and the term of human generation.
And so the Philosopher says (De Anima iii) that the intellect is
separate, because it is not the faculty of a corporeal organ.

From this it is clear how to answer the Second and Third objections:
since, in order tha