te matter,
on which it is first imprinted at the generation of that individual,
so that it never leaves that matter until the ultimate dissolution of
the individual. And this matter, say they, principally belongs to the
true human nature. But since this matter does not suffice for the
requisite quantity, some other matter must be added, through the
change of food into the substance of the individual partaking
thereof, in such a quantity as suffices for the increase required.
And this matter, they state, belongs secondarily to the true human
nature: because it is not required for the primary existence of the
individual, but for the quantity due to him. And if anything further
is produced from the food, this does not belong to true human nature,
properly speaking. However, this also is inadmissible. First, because
this opinion judges of living bodies as of inanimate bodies; in
which, although there be a power of generating their like in species,
there is not the power of generating their like in the individual;
which power in living bodies is the nutritive power. Nothing,
therefore, would be added to living bodies by their nutritive power,
if their food were not changed into their true nature. Secondly,
because the active seminal power is a certain impression derived from
the soul of the begetter, as stated above (Q. 118, A. 1). Hence it
cannot have a greater power in acting, than the soul from which it is
derived. If, therefore, by the seminal power a certain matter truly
assumes the form of human nature, much more can the soul, by the
nutritive power, imprint the true form of human nature on the food
which is assimilated. Thirdly, because food is needed not only for
growth, else at the term of growth, food would be needful no longer;
but also to renew that which is lost by the action of natural heat.
But there would be no renewal, unless what is formed from the food,
took the place of what is lost. Wherefore just as that which was
there previously belonged to true human nature, so also does that
which is formed from the food.

Therefore, according to others, it must be said that the food is
really changed into the true human nature by reason of its assuming
the specific form of flesh, bones and such like parts. This is what
the Philosopher says (De Anima ii, 4): "Food nourishes inasmuch as
it is potentially flesh."

Reply Obj. 1: Our Lord does not say that the "whole" of what enters
into the mouth, but "all"--because