fore, that the semen is not something
separated from what was before the actual whole; rather is it the
whole, though potentially, having the power, derived from the soul of
the begetter, to produce the whole body, as stated above (A. 1; Q.
108, A. 1). Now that which is in potentiality to the whole, is that
which is generated from the food, before it is transformed into the
substance of the members. Therefore the semen is taken from this. In
this sense the nutritive power is said to serve the generative power:
because what is transformed by the nutritive power is employed as
semen by the generative power. A sign of this, according to the
Philosopher, is that animals of great size, which require much food,
have little semen in proportion to the size of their bodies, and
generate seldom; in like manner fat men, and for the same reason.

Reply Obj. 1: Generation is from the substance of the begetter in
animals and plants, inasmuch as the semen owes its virtue to the
form of the begetter, and inasmuch as it is in potentiality to the
substance.

Reply Obj. 2: The likeness of the begetter to the begotten is on
account not of the matter, but of the form of the agent that
generates its like. Wherefore in order for a man to be like his
grandfather, there is no need that the corporeal seminal matter
should have been in the grandfather; but that there be in the semen a
virtue derived from the soul of the grandfather through the father.
In like manner the third objection is answered. For kinship is not in
relation to matter, but rather to the derivation of the forms.

Reply Obj. 4: These words of Augustine are not to be understood as
though the immediate seminal virtue, or the corporeal substance from
which this individual was formed were actually in Adam: but so that
both were in Adam as in principle. For even the corporeal matter,
which is supplied by the mother, and which he calls the corporeal
substance, is originally derived from Adam: and likewise the active
seminal power of the father, which is the immediate seminal virtue
(in the production) of this man.

But Christ is said to have been in Adam according to the "corporeal
substance," not according to the seminal virtue. Because the matter
from which His Body was formed, and which was supplied by the Virgin
Mother, was derived from Adam; whereas the active virtue was not
derived from Adam, because His Body was not formed by the seminal
virtue of a man, but by the operat