an Himself in human nature.

Further, Christ in His human nature is the servant of God the Father,
according to John 20:17: "I ascend to My Father and to your Father to
My God and your God." Now whoever is the servant of the Father is the
servant of the Son; otherwise not everything that belongs to the
Father would belong to the Son. Therefore Christ is His own servant
and is subject to Himself.

_I answer that,_ As was said above (A. 1, ad 2), to be master or
servant is attributed to a person or hypostasis according to a
nature. Hence when it is said that Christ is the master or servant of
Himself, or that the Word of God is the Master of the Man Christ,
this may be understood in two ways. First, so that this is understood
to be said by reason of another hypostasis or person, as if there was
the person of the Word of God ruling and the person of the man
serving; and this is the heresy of Nestorius. Hence in the
condemnation of Nestorius it is said in the Council of Ephesus (Part
III, ch. i, anath. 6): "If anyone say that the Word begotten of God
the Father is the God or Lord of Christ, and does not rather confess
the same to be at once God and man as the Word made flesh, according
to the Scriptures, let him be anathema." And in this sense it is
denied by Cyril and Damascene (Obj. 1); and in the same sense must it
be denied that Christ is less than Himself or subject to Himself.
Secondly, it may be understood of the diversity of natures in the one
person or hypostasis. And thus we may say that in one of them, in
which He agrees with the Father, He presides and rules together with
the Father; and in the other nature, in which He agrees with us, He
is subject and serves, and in this sense Augustine says that "the Son
is less than Himself."

Yet it must be borne in mind that since this name "Christ" is the
name of a Person, even as the name "Son," those things can be
predicated essentially and absolutely of Christ which belong to Him
by reason of the Person, Which is eternal; and especially those
relations which seem more properly to pertain to the Person or the
hypostasis. But whatever pertains to Him in His human nature is
rather to be attributed to Him with a qualification; so that we say
that Christ is simply greatest, Lord, Ruler, whereas to be subject or
servant or less is to be attributed to Him with the qualification, in
His human nature.

Reply Obj. 1: Cyril and Damascene deny that Christ is the head of
Hims