Chapter VII

It remains for us to show how in accordance with the affirmation of
Catholic belief Christ consists at once in and of both natures.

The statement that a thing consists of two natures bears two meanings;
one, when we say that anything is a union of two natures, as e.g. honey
and water, where the union is such that in the combination, however the
elements be confounded, whether by one nature changing into the other,
or by both mingling with each other, the two entirely disappear. This is
the way in which according to Eutyches Christ consists of two natures.

The other way in which a thing can consist of two natures is when it is
so combined of two that the elements of which it is said to be combined
continue without changing into each other, as when we say that a crown
is composed of gold and gems. Here neither is the gold converted into
gems nor is the gem turned into gold, but both continue without
surrendering their proper form.

Things then like this, composed of various elements, we say consist also
in the elements of which they are composed. For in this case we can say
that a crown is composed of gems and gold, for gems and gold are that in
which the crown consists. For in the former mode of composition honey
and water is not that in which the resulting union of both consists.

Since then the Catholic Faith confesses that both natures continue in
Christ and that they both remain perfect, neither being transformed into
the other, it says with right that Christ consists both in and of the
two natures; _in_ the two because both continue, _of_ the two
because the One Person of Christ is formed by the union of the two
continuing natures.

But the Catholic Faith does not hold the union of Christ out of two
natures according to that sense which Eutyches puts upon it. For the
interpretation of the conjunction out of two natures which he adopts
forbids him to confess consistence in two or the continuance of the two
either; but the Catholic adopts an interpretation of the consistence out
of two which comes near to that of Eutyches, yet keeps the
interpretation which confesses consistence in two.

"To consist of two natures" is therefore an equivocal or rather a
doubtful term of double meaning denoting different things; according to
one of its interpretations the substances out of which the union is said
to have been composed do not continue, according to another the union
effected of the two is such that both natures continue.

When once this knot of doubt or ambiguity has been untied, nothing
further can be advanced to shake the true and solid content of the
Catholic Faith, which is that the same Christ is perfect man and God,
and that He who is perfect man and God is One God and Son of Man, that,
however, quaternity is not added to the Trinity by the addition of human
nature to perfect Godhead, but that one and the same Person completes
the number of the Trinity, so that, although it was the manhood which
suffered, yet God can be said to have suffered, not by manhood becoming
Godhead but by manhood being assumed by Godhead. Further, He who is man
is called Son of God not in virtue of divine but of human substance,
which latter none the less was conjoined to Godhead in a unity of
natures. And although thought is able to distinguish and combine the
manhood and the Godhead, yet one and the same is perfect man and God,
God because He was begotten of the substance of the Father, but man
because He was engendered of the Virgin Mary. And further He who is man
is God in that manhood was assumed by God, and He who is God is man in
that God was clothed with manhood. And although in the same Person the
Godhead which took manhood is different from the manhood which It took,
yet the same is God and man. For if you think of man, the same is man
and God, being man by nature, God by assumption. But if you think of
God, the same is God and man, being God by nature, man by assumption.
And in Him nature becomes double and substance double because He is God-
man, and One Person since the same is man and God. This is the middle
way between two heresies, just as virtues also hold a middle place.[75]
For every virtue has a place of honour midway between extremes. For if
it stands beyond or below where it should it ceases to be virtue. And so
virtue holds a middle place.

Wherefore if the following four assertions can be said to be neither
beyond or below reason, viz. that in Christ are either two Natures and
two Persons as Nestorius says, or one Person and one Nature as Eutyches
says, or two Natures but one Person as the Catholic Faith believes, or
one Nature and two Persons, and inasmuch as we have refuted the doctrine
of two Natures and two Persons in our argument against Nestorius and
incidentally have shown that the one Person and one Nature suggested by
Eutyches is impossible--since there has never been anyone so mad as to
believe that His Nature was single but His Person double--it remains
that the article of belief must be true which the Catholic Faith
affirms, viz. that the Nature is double, but the Person one. But as I
have just now remarked that Eutyches confesses two Natures in Christ
before the union, but only one after the union, and since I proved that
under this error lurked two opposite opinions, one, that the union was
brought about by conception although the human body was certainly not
taken from Mary; the other, that the body taken from Mary formed part of
the union by means of the Resurrection, I have, it seems to me, argued
the twofold aspect of the case as completely as it deserves. What we
have now to inquire is how it came to pass that two Natures were
combined into one Substance.

[75] _Vide supra_, p. 100 note.