God by the grace of adoption, but what is Divine is united to man;
hence, not God but man is perfected.

Reply Obj. 2: A Divine Person is said to be incommunicable inasmuch
as It cannot be predicated of several supposita, but nothing prevents
several things being predicated of the Person. Hence it is not
contrary to the nature of person to be communicated so as to subsist
in several natures, for even in a created person several natures may
concur accidentally, as in the person of one man we find quantity and
quality. But this is proper to a Divine Person, on account of its
infinity, that there should be a concourse of natures in it, not
accidentally, but in subsistence.

Reply Obj. 3: As was said above (Q. 2, A. 1), the human nature
constitutes a Divine Person, not simply, but forasmuch as the Person
is denominated from such a nature. For human nature does not make the
Son of Man to be simply, since He was from eternity, but only to be
man. It is by the Divine Nature that a Divine Person is constituted
simply. Hence the Divine Person is not said to assume the Divine
Nature, but to assume the human nature.
_______________________

SECOND ARTICLE [III, Q. 3, Art. 2]

Whether It Is Befitting to the Divine Nature to Assume?

Objection 1: It would seem that it is not befitting to the Divine
Nature to assume. Because, as was said above (A. 1), to assume is to
take to oneself. But the Divine Nature did not take to Itself human
nature, for the union did not take place in the nature, as was said
above (Q. 2, AA. 1, 3). Hence it is not befitting to the Divine
Nature to assume human nature.

Obj. 2: Further, the Divine Nature is common to the three Persons.
If, therefore, it is befitting to the Divine Nature to assume, it
consequently is befitting to the three Persons; and thus the Father
assumed human nature even as the Son, which is erroneous.

Obj. 3: Further, to assume is to act. But to act befits a person, not
a nature, which is rather taken to be the principle by which the
agent acts. Therefore to assume is not befitting to the nature.

_On the contrary,_ Augustine (Fulgentius) says (De Fide ad Petrum
ii): "That nature which remains eternally begotten of the Father"
(i.e. which is received from the Father by eternal generation) "took
our nature free of sin from His Mother."

_I answer that,_ As was said above (A. 1), in the word assumption two
things are signified--to wit, the principle and the term of the
acti