Christ's concrete human nature

One of the old puzzles of Christology is why it is that in us the soul and body together compose a person, but they do not do so in Christ.

The problem is intensified if one thinks that there is an entity composed of the soul and body of Christ, an entity one might call “Christ’s concrete human nature”. For the person of Peter just is the entity composed of the soul and body of Christ, while in Christ the quite similar (except in sin) entity composed of the body and soul is not a person, but rather is united to a person.

The standard way out of this difficulty is to say that being a person is an extrinsic feature of a concrete human nature. Thus, Peter’s concrete human nature is a person because it is not united to a person distinct from it. But Christ’s concrete human nature is not a person because it is united to a person distinct from it. A problematic consequence of this is that personhood is not an intrinsic feature of an entity.

But there is a better way to get out of the difficulty. Just deny that in Christ there is any entity composed of his soul and body, and any statements about “Christ’s human nature” we need to make about his concrete soul and body should get paraphrased as statements about two entities, Christ’s soul and Christ’s body. Since there is no such entity as Christ’s concrete human nature, there is no puzzle as to why this entity isn’t a person.

This also solves another problem. If there is such a thing as Christ’s concrete human nature, then plausibly it thinks human thoughts, just as Peter’s concrete human nature thinks human thoughts. But Christ also thinks human thoughts. So in Christ there are two human thinkers: Christ and Christ’s concrete human nature. This is implausible! Granted, we can get out of it by making human thinking extrinsic as well, but each time we do the extrinsicness move, we intensify puzzlement.

But there is still a problem: Why is it that Peter’s soul and Peter’s body compose a whole—namely, Peter’s person—while Christ’s soul and Christ’s body do not compose a whole? Here we should make an extrinsic move. Christ’s soul and Christ’s body do not compose a whole because they are personally united to something else. Peter’s soul and Peter’s body, however, are not personally united to something else (I don’t count composition as personal union).

It may seem like at this point we have made no progress: we are back to an extrinsicness move. But this extrinsicness move is plausible in non-theological cases. Suppose Fred is missing a left leg. Then Fred’s soul, head, arms, torso, and right leg compose a whole. But Peter’s soul, head, arms, torso, and right leg do not compose a whole. Why the difference? Because Peter’s soul, head, arms, torso, and right leg are personally united to something else–namely, a left leg. But Fred’s soul, head, arms, torso, and right leg are not personally united to something else.

There is another worry. Suppose we embrace survivalism and think that Peter continues to exist in a disembodied way after death and before the resurrection of the body. But now Peter’s concrete human nature is reduced to a soul, and the soul does exist. So now Peter’s soul is a person, while Christ’s soul is not, even though both exist and are intrinsically alike (apart from accidental features). However, I think there is a way out of this, too. We deny that Peter’s soul is a person. The easiest way is to go four-dimensionalist: Peter’s soul is just a part of a four-dimensional entity that includes a body, though the body doesn’t happen to exist at this time. A less easy, but still tenable, way is to say that disembodied Peter has the soul as a proper part, with no co-part, and classical mereology needs to be modified to avoid Weak Supplementation (which is the axiom that says that if an object has a proper part, then it has another non-overlapping part).