to be apt
for conception. And therefore of such matter was Christ's body
conceived.

Reply Obj. 1: Since the Blessed Virgin was of the same nature as
other women, it follows that she had flesh and bones of the same
nature as theirs. Now, flesh and bones in other women are actual
parts of the body, the integrity of which results therefrom: and
consequently they cannot be taken from the body without its being
corrupted or diminished. But as Christ came to heal what was corrupt,
it was not fitting that He should bring corruption or diminution to
the integrity of His Mother. Therefore it was becoming that Christ's
body should be formed not from the flesh or bones of the Virgin, but
from her blood, which as yet is not actually a part, but is
potentially the whole, as stated in _De Gener. Animal._ i. Hence He
is said to have taken flesh from the Virgin, not that the matter from
which His body was formed was actual flesh, but blood, which is flesh
potentially.

Reply Obj. 2: As stated in the First Part (Q. 92, A. 3, ad 2), Adam,
through being established as a kind of principle of human nature, had
in his body a certain proportion of flesh and bone, which belonged to
him, not as an integral part of his personality, but in regard to his
state as a principle of human nature. And from this was the woman
formed, without detriment to the man. But in the Virgin's body there
was nothing of this sort, from which Christ's body could be formed
without detriment to His Mother's body.

Reply Obj. 3: Woman's semen is not apt for generation, but is
something imperfect in the seminal order, which, on account of the
imperfection of the female power, it has not been possible to bring
to complete seminal perfection. Consequently this semen is not the
necessary matter of conception; as the Philosopher says (De Gener.
Animal. i): wherefore there was none such in Christ's conception: all
the more since, though it is imperfect in the seminal order, a
certain concupiscence accompanies its emission, as also that of the
male semen: whereas in that virginal conception there could be no
concupiscence. Wherefore Damascene says (De Fide Orth. iii) that
Christ's body was not conceived "seminally." But the menstrual blood,
the flow of which is subject to monthly periods, has a certain
natural impurity of corruption: like other superfluities, which
nature does not heed, and therefore expels. Of such menstrual blood
infected with corruption and repudiated