You must consider that all I have said so far has been for the purpose
of marking the difference between Nature and Person, that is, [Greek:
ousia] and [Greek: hupostasis]. The exact terms which should be applied
in each case must be left to the decision of ecclesiastical usage. For
the time being let that distinction between Nature and Person hold which
I have affirmed, viz. that Nature is the specific property of any
substance, and Person the individual substance of a rational nature.
Nestorius affirmed that in Christ Person was twofold, being led astray
by the false notion that Person may be applied to every nature. For on
this assumption, understanding that there were in Christ two natures, he
declared that there were likewise two persons. And although the
definition which we have already given is enough to prove Nestorius
wrong, his error shall be further declared by the following argument. If
the Person of Christ is not single, and if it is clear that there are in
Him two natures, to wit, divine and human (and no one will be so foolish
as to fail to include either in the definition), it follows that there
must apparently be two persons; for Person, as has been said, is the
individual substance of a rational nature.
What kind of union, then, between God and man has been effected? Is it
as when two bodies are laid the one against the other, so that they are
only joined locally, and no touch of the quality of the one reaches the
other--the kind of union which the Greeks term [Greek: kata parathesin]
"by juxtaposition"? But if humanity has been united to divinity in this
way no one thing has been formed out of the two, and hence Christ is
nothing. The very name of Christ, indeed, denotes by its singular number
a unity. But if the two persons continued and such a union of natures as
we have above described took place, there could be no unity formed from
two things, for nothing could ever possibly be formed out of two
persons. Therefore Christ is, according to Nestorius, in no respect one,
and therefore He is absolutely nothing. For what is not one cannot exist
either; because Being and unity are convertible terms, and whatever is
one is. Even things which are made up of many items, such as a heap or
chorus, are nevertheless a unity. Now we openly and honestly confess
that Christ is; therefore we say that Christ is a Unity. And if this is
so, then without controversy the Person of Christ is one also. For if
the Persons were two He could not be one; but to say that there are two
Christs is nothing else than the madness of a distraught brain. Could
Nestorius, I ask, dare to call the one man and the one God in Christ two
Christs? Or why does he call Him Christ who is God, if he is also going
to call Him Christ who is man, when his combination gives the two no
common factor, no coherence? Why does he wrongly use the same name for
two utterly different natures, when, if he is compelled to define
Christ, he cannot, as he himself admits, apply the substance of one
definition to both his Christs? For if the substance of God is different
from that of man, and the one name of Christ applies to both, and the
combination of different substances is not believed to have formed one
Person, the name of Christ is equivocal[66] and cannot be comprised in
one definition. But in what Scriptures is the name of Christ ever made
double? Or what new thing has been wrought by the coming of the Saviour?
For the truth of the faith and the unwontedness of the miracle alike
remain, for Catholics, unshaken. For how great and unprecedented a thing
it is--unique and incapable of repetition in any other age--that the
nature of Him who is God alone should come together with human nature
which was entirely different from God to form from different natures by
conjunction a single Person! But now, if we follow Nestorius, what
happens that is new? "Humanity and divinity," quoth he, "keep their
proper Persons." Well, when had not divinity and humanity each its
proper Person? And when, we answer, will this not be so? Or wherein is
the birth of Jesus more significant than that of any other child, if,
the two Persons remaining distinct, the natures also were distinct? For
while the Persons remained so there could no more be a union of natures
in Christ than there could be in any other man with whose substance, be
it never so perfect, no divinity was ever united because of the
subsistence of his proper person. But for the sake of argument let him
call Jesus, i.e. the human person, Christ, because through that person
God wrought certain wonders. Agreed. But why should he call God Himself
by the name of Christ? Why should he not go on to call the very elements
by that name? For through them in their daily movements God works
certain wonders. Is it because irrational substances cannot possess a
Person enabling them to receive the name of Christ? Is not the operation
of God seen plainly in men of holy life and notable piety? There will
surely be no reason not to call the saints also by that name, if Christ
taking humanity on Him is not one Person through conjunction. But
perhaps he will say, "I allow that such men are called Christs, but it
is because they are in the image of the true Christ." But if no one
Person has been formed of the union of God and man, we shall consider
all of them just as true Christs as Him who, we believe, was born of a
Virgin. For no Person has been made one by the union of God and man
either in Him or in them who by the Spirit of God foretold the coming
Christ, for which cause they too were called Christs. So now it follows
that so long as the Persons remain, we cannot in any wise believe that
humanity has been assumed by divinity. For things which differ alike in
persons and natures are certainly separate, nay absolutely separate; man
and oxen are not further separate than are divinity and humanity in
Christ, if the Persons have remained. Men indeed and oxen are united in
one animal nature, for by genus they have a common substance and the
same nature in the collection which forms the universal.[67] But God and
man will be at all points fundamentally different if we are to believe
that distinction of Persons continues under difference of nature. Then
the human race has not been saved, the birth of Christ has brought us no
salvation, the writings of all the prophets have but beguiled the people
that believed in them, contempt is poured upon the authority of the
whole Old Testament which promised to the world salvation by the birth
of Christ. It is plain that salvation has not been brought us, if there
is the same difference in Person that there is in Nature. No doubt He
saved that humanity which we believe He assumed; but no assumption can
be conceived, if the separation abides alike of Nature and of Person.
Hence that human nature which could not be assumed as long as the Person
continued, will certainly and rightly appear incapable of salvation by
the birth of Christ. Wherefore man's nature has not been saved by the
birth of Christ--an impious conclusion.[68]
But although there are many weapons strong enough to wound and demolish
the Nestorian view, let us for the moment be content with this small
selection from the store of arguments available.
[66] Cf. the discussion of _aequiuoca_=[Greek: homonumos] in _Isag.
Porph. Vide_ Brandt's Index.
[67] Vniuersalitas=[Greek: to katholou].
[68] For a similar _reductio ad absurdum_ ending in _quod nefas est_ see
_Tr._ iii. (_supra_, p. 44) and _Cons._ v. 3 (_infra_, p. 374).