II. Do the two natures of Christ constitute one or more persons?

There are two natures in Christ, whole and distinct; but only one person. Marcion taught that there were two Christs: the one crucified, the other not: and that the one came to the assistance of the other upon the cross. But it behooved one to be Christ, because it was necessary that one should be mediator both by merit and efficacy. Therefore there must needs be only one person.

Obj. 1. In whom there are two things which constitute two entire persons, in him there are also two persons. In Christ there are two natures which constitute two entire persons; for the Word is a complete person, whilst body and soul also constitute a person. Therefore there are two persons in Christ. Ans. We deny that part of the minor proposition which affirms that body and soul, in connection with the Word, constitute a person. This appears to be false, according to the definition which we have given of person, which does not belong to the human nature assumed by the Word; for it does not subsist by itself, but is sustained in, and by another, viz., in and by the Word. It was formed and assumed by the Word at one and the same time, and never would have existed, unless it had been assumed by the Word; nor could it even now exist were it not sustained by the Word. It is also a part of another, viz., of the mediator. But a person, according to the definition which we have given, is something individual, intelligent, subsisting by itself, not sustained by another, nor part of another. Hence it is evident that the human nature of Christ is not in, and of itself, a proper person, although it may be said to belong to the substance of Christ, and to be a part of him. The Word, however, was and is a person, and yet has a relation to our nature in as far as he has taken it upon himself. Hence it is correct to say: the person took the nature, and the nature assumed a nature; but we cannot correctly say, the person took a person, or the nature took a person; for the human nature which is in Christ was created in order that it might be made a part of another, so that we may properly say that it is a part of another; yet, when we so speak, all imperfections must be carefully excluded. Many, however, refrain from the use of such language in consequence of the dangers and abuses to which it may lead. Yet Damascenus and others often use this form of speaking.

Obj. 2. But, according to this the Word cannot be a person, because he is a part of the person; and that which is only a part cannot be a person. Ans. That which is only part of a person (and such a part that is not of itself a person) is no person; or, that which is a part of a person, is not that person of which it is a part. And so it may be said of the Word, if it be properly understood, that he is not the whole person of the mediator, although he is in, and of himself, a whole and complete person in respect to the Godhead.
Obj. 3. God and man are two persons. Christ is God and man. Therefore there are two persons in him. Ans. The major is true if we understand God and man as existing separately, without any union. But Christ is God and man in union. There is, therefore, here a fallacy of composition and division; for in the major proposition God and man are taken disjunctively, or as existing separately; and in the minor conjunctively, or as joined together.

Reply 1. But the Word united to himself a body and soul; and therefore a person. Ans. It is true indeed, he united these to himself, but it was by a personal union, so that the body and soul which Christ took, do not exist by themselves, but in the person of the Word.

Reply 2. But he united to himself the essential parts of a person, and therefore he must also have united a person. Ans. This holds true merely in relation to such parts as subsist by themselves ; but the body and soul of Christ do not subsist, nor could they ever have subsisted, unless in this union.