dental, which will be
disproved later on (A. 6). Secondly, because thereby we should not
have an absolute unity, but relative only, for there remain several
things actually. Thirdly, because the form of such is not a nature,
but an art, as the form of a house; and thus one nature would not be
constituted in Christ, as they wish.

Secondly, one thing is made up of several things, perfect but
changed, as a mixture is made up of its elements; and in this way
some have said that the union of the Incarnation was brought about by
manner of combination. But this cannot be. First, because the Divine
Nature is altogether immutable, as has been said (I, Q. 9, AA. 1, 2),
hence neither can it be changed into something else, since it is
incorruptible; nor can anything else be changed into it, for it
cannot be generated. Secondly, because what is mixed is of the same
species with none of the elements; for flesh differs in species from
any of its elements. And thus Christ would be of the same nature
neither with His Father nor with His Mother. Thirdly, because there
can be no mingling of things widely apart; for the species of one of
them is absorbed, e.g. if we were to put a drop of water in a flagon
of wine. And hence, since the Divine Nature infinitely exceeds the
human nature, there could be no mixture, but the Divine Nature alone
would remain.

Thirdly, a thing is made up of things not mixed nor changed, but
imperfect; as man is made up of soul and body, and likewise of divers
members. But this cannot be said of the mystery of the Incarnation.
First, because each nature, i.e. the Divine and the human, has its
specific perfection. Secondly, because the Divine and human natures
cannot constitute anything after the manner of quantitative parts, as
the members make up the body; for the Divine Nature is incorporeal;
nor after the manner of form and matter, for the Divine Nature cannot
be the form of anything, especially of anything corporeal, since it
would follow that the species resulting therefrom would be
communicable to several, and thus there would be several Christs.
Thirdly, because Christ would exist neither in human nature nor in
the Divine Nature: since any difference varies the species, as unity
varies number, as is said (Metaph. viii, text. 10).

Reply Obj. 1: This authority of Cyril is expounded in the Fifth Synod
(i.e. Constantinople II, coll. viii, can. 8) thus: "If anyone
proclaiming one nature of the Word of God