is not
composite. For the Person of Christ is naught else than the Person or
hypostasis of the Word, as appears from what has been said (A. 2).
But in the Word, Person and Nature do not differ, as appears from
First Part (Q. 39, A. 1). Therefore since the Nature of the Word is
simple, as was shown above (I, Q. 3, A. 7), it is impossible that the
Person of Christ be composite.

Obj. 2: Further, all composition requires parts. But the Divine
Nature is incompatible with the notion of a part, for every part
implicates the notion of imperfection. Therefore it is impossible
that the Person of Christ be composed of two natures.

Obj. 3: Further, what is composed of others would seem to be
homogeneous with them, as from bodies only a body can be composed.
Therefore if there is anything in Christ composed of the two natures,
it follows that this will not be a person but a nature; and hence the
union in Christ will take place in the nature, which is contrary to
A. 2.

_On the contrary,_ Damascene says (De Fide Orth. iii, 3, 4, 5), "In
the Lord Jesus Christ we acknowledge two natures, but one hypostasis
composed from both."

_I answer that,_ The Person or hypostasis of Christ may be viewed in
two ways. First as it is in itself, and thus it is altogether simple,
even as the Nature of the Word. Secondly, in the aspect of person or
hypostasis to which it belongs to subsist in a nature; and thus the
Person of Christ subsists in two natures. Hence though there is one
subsisting being in Him, yet there are different aspects of
subsistence, and hence He is said to be a composite person, insomuch
as one being subsists in two.

And thereby the solution to the first is clear.

Reply Obj. 2: This composition of a person from natures is not
so called on account of parts, but by reason of number, even as that
in which two things concur may be said to be composed of them.

Reply Obj. 3: It is not verified in every composition, that
the thing composed is homogeneous with its component parts, but only
in the parts of a continuous thing; for the continuous is composed
solely of continuous [parts]. But an animal is composed of soul and
body, and neither of these is an animal.
_______________________

FIFTH ARTICLE [III, Q. 2, Art. 5]

Whether in Christ There Is Any Union of Soul and Body?

Objection 1: It would seem that in Christ there was no union of soul
and body. For from the union of soul and body in us a person or a
human hypo