attributed to that Person: both when a word is
employed to stand for it, signifying the Divine Nature, and when a
word is used signifying the human nature. Now, conception and birth
are attributed to the person and hypostasis in respect of that nature
in which it is conceived and born. Since, therefore, the human nature
was taken by the Divine Person in the very beginning of the
conception, as stated above (Q. 33, A. 3), it follows that it can be
truly said that God was conceived and born of the Virgin. Now from
this is a woman called a man's mother, that she conceived him and
gave birth to him. Therefore the Blessed Virgin is truly called the
Mother of God. For the only way in which it could be denied that the
Blessed Virgin is the Mother of God would be either if the humanity
were first subject to conception and birth, before this man were the
Son of God, as Photinus said; or if the humanity were not assumed
unto unity of the Person or hypostasis of the Word of God, as
Nestorius maintained. But both of these are erroneous. Therefore it
is heretical to deny that the Blessed Virgin is the Mother of God.

Reply Obj. 1: This was an argument of Nestorius, and it is solved by
saying that, although we do not find it said expressly in Scripture
that the Blessed Virgin is the Mother of God, yet we do find it
expressly said in Scripture that "Jesus Christ is true God," as may
be seen 1 John 5:20, and that the Blessed Virgin is the "Mother of
Jesus Christ," which is clearly expressed Matt. 1:18. Therefore, from
the words of Scripture it follows of necessity that she is the Mother
of God.

Again, it is written (Rom. 9:5) that Christ is of the Jews "according
to the flesh, who is over all things, God blessed for ever." But He
is not of the Jews except through the Blessed Virgin. Therefore He
who is "above all things, God blessed for ever," is truly born of the
Blessed Virgin as of His Mother.

Reply Obj. 2: This was an argument of Nestorius. But Cyril, in a
letter against Nestorius [*Cf. Acta Conc. Ephes., p. 1, cap. ii],
answers it thus: "Just as when a man's soul is born with its body,
they are considered as one being: and if anyone wish to say that the
mother of the flesh is not the mother of the soul, he says too much.
Something like this may be perceived in the generation of Christ. For
the Word of God was born of the substance of God the Father: but
because He took flesh, we must of necessity confess that in the flesh
H