Brian Leftow on “One Person Christology”

How can a Chalcedonian Christology avoid ending up with Christ being two people? If the divine logos (the second person of the Trinity) combined with a fully functioning human body and soul (which some people take to be the ingredients of a human being), that is surely two people and not one, right?

According to the orthodox way of describing the person Jesus Christ who walked around in Judea, performed miracles, ate the last supper, died and rose again, he is one person who is truly divine and truly human. One of the major concerns of the famous “Definition of Chalcedon” was to stress that Jesus did not simply appear to be human, rather he was truly human in addition to being truly divine. Jesus had everything that is required in order to be a particular human being. Having a dualistic view of what it means to be a human being, the theologians who wrote this definition believed, meant having a physical human body and a non-physical human soul, and accordingly they described the person of Jesus as follows:

This selfsame one is perfect both in deity and in humanness; this selfsame one is also actually God and actually man, with a rational soul and a body. He is of the same reality as God as far as his deity is concerned and of the same reality as we ourselves as far as his humanness is concerned.

The “rational soul” here is the human soul. I may as well say that while I agree with what the framers of this statement were trying to say – namely that Jesus really was truly human, I do not share their view of what is required in order for a human being to exist – namely a body and a soul. But this is not what I want to discuss here. The point is that they considered that Jesus had everything required in order for a complete human nature to exist – which in their view required them to say that Jesus had all the ingredients of a human being, namely a human body and soul, and that the Son of God as the second person of the Trinity (also called the Logos or the Word, following John’s description in John 1:1) was a divine person with or without the incarnation, so his divinity consisted in the presence of the Logos in Jesus.

A number of theologians and philosophers of religion have noted, however, that if you’re talking about these three ingredients but only about one person, then you’re in a difficult position. Surely, they say, a complete human person like you or me consists of a human body plus a human soul. If those two things are present, then a human person is present. They might read Genesis 2:7, the creation of Adam, and say that God formed a body from matter and breathed into it something immaterial, a spirit, you might call it, and when you have those two things together, one of us is present.1 So the fact that in Jesus there is a human body and a human soul means, it follows, that a complete human person is present. But then if you add to this the Logos, the eternal son of God, one of the persons of the Trinity, then it must follow, these objectors note, that whereas we already had one person, we now have two. So Jesus of Nazareth is really two persons, not one. Indeed, on this model, the Son of God did not become a human being at all, he merely came alongside a complete human being. The view that Jesus of Nazareth was really two persons, one human and one divine, was called Nestorianism (after Nestorius) and falls unambiguously outside of Christian orthodoxy.

On reflection, a doctrine of the Incarnation thus described has no real advantage over the “Gnostic” Christologies (descriptions of the person of Christ) that the orthodox faith tried to distance itself from. Consider what those Gnostic views are widely reported to have been like: Jesus of Nazareth was a man upon whom the divine Spirit, Christ, descended (at his baptism). Then on the cross, Christ sacrificed, not himself (heaven forbid!), but that human being instead, while the Spirit of Christ lived on. Is there really any important difference between this, one might ask, and a view in which the Son of God joins hands, so to speak, with an already complete human nature with a body and soul?

One solution is that of William Lane Craig and J. P. Moreland (in their book Philosophical Foundations of a Christian Worldview). They opt for a view that they identify with that of Apollinarius, widely regarded as heretical but, they claim, simply misunderstood. Apollinarius is accused of saying that Jesus did not have a full human nature. Instead, the Incarnation was a combination of the Logos with a human body (so there is no human “rational soul”). That way the person is really divine, Jesus still has a human aspect, and there is only one person. Craig and Moreland allege that Apollinarius was simply misunderstood here. They seek to rehabilitate both his view and his reputation, by claiming that actually, there is no need for a “rational soul” in addition to the human body and the Logos, for the Logos already has within it everything that is necessary for a human rational soul to exist. It contains within itself the archetype of human personhood, the perfect human mind, so that the Logos is fully divine but also the blueprint for humanity (my summary). Therefore in combining with a human body, the Logos caused the result to be a person both fully human and divine, having a human body, a rational soul, and the divine Logos (which was also the rational soul).2

Whatever problems Craig and Moreland may be solving, it is hard to call their solution historically orthodox, as there is very little doubt that the theologians of Chalcedon conceived of the Logos taking to itself a complete human nature in the incarnation, rather than “bringing” part of that human nature into the world with it and receiving only part of it (the less significant part, a dualist would think) by becoming incarnate.3 The chief objection to Apollinarianism throughout history applies with equal force to the view of Craig and Moreland: That which is not assumed is not redeemed. The logos took to itself human nature in order to redeem it, and if the logos did not take complete human nature to itself but only part of it (because it already had some aspects of human nature within itself, albeit not in need of redemption), then human nature is not redeemed through the work of Christ. That is one reason that I am not going to defend their view. I am also not trying to defend that view because I happen to think it is false, as I do not think that a human being requires a rational soul (i.e. an immaterial soul, in principle not dependent on a body for life or existence) in order to be complete – but that is another matter. The question that interests me here is whether or not the historically orthodox view – That the Logos came into the world as a complete divine person and nothing else, and took to itself a complete human nature including a rational soul – can withstand the charge that it results in there being two persons in Jesus of Nazareth.

In fact I’m not really going to answer that question, but I am going to offer somebody else’s answer for your consideration. The problem, restated again: How can there be a human body and soul without there being a human person? Isn’t a human person a human body and soul? To summarise Brian Leftow’s answer in my own words is this: That all depends on what you mean by “is.” And this is not mere hair splitting, as this answer may sound to those outside of philosophy. We can mean a range of things by the word “is.” For example when I say “Bruce is tall,” I am ascribing a property to Kevin, the property of tallness. But when I say “Bruce is Batman,” I am making a statement about identity: The person who is Bruce Wayne is identical with the person who is Batman. Unless one of these people existed, the other one would not exist.4 Similarly, when we say that “The combination of a human body and a human soul is a human person,” there are a couple of things we could mean. We might mean that the combination of a human body and a human soul is identical with a particular human person, so that the existence of a human body and a human soul is a sufficient condition for the existence of a human person. If this statement is true then the combination of the second person of the Trinity with a human body and soul necessarily counts as two people and Nestorianism is true.

But, asks Leftow, what if this is not what we (should) mean by “is” here? What if by “is” we mean “constitutes”? If this is so, then we are saying “the combination of a human body and a human soul is what constitutes a human person.” The distinction may appear a subtle one to many, but it makes a difference. Think of a marble statue of David. It is made of a heavy piece of marble, but it is not just identical with a heavy piece of marble so that wherever there is a heavy piece of marble, there is a statue of David. Not every heavy piece of marble is a statue of David. The statue is constituted by a heavy piece of marble that has been co-opted into the “act” (if we can speak of marble as acting) of participating in the existence of a statue of David. Or (to use an example that is in more similar territory) consider the distinction among materialist philosophies of mind between a brain-identity or perhaps body-identity theory, in which you are identical with a specific brain or body, and a constitution view of human persons, like that of Kevin Corcoran, in which a particular human body constitutes you and is caught up in the life that is yours, but is not identical with you.5 Leftow proposes that if we think of a human being or person, not as being identical with a particular body and soul, but as being constituted by a particular body and soul, we can go on to think of circumstances under which a human body both exist in combination but fail to constitute a human person. One such possible example, he proposes, is the incarnation of the Logos. He explains a possible model as follows (note: “concretism” in this context is the view that in the incarnation the logos was combined with the substances required for a human being, namely a body and (if necessary) a soul):

One [reply] is that the Son assumes Christ’s body (henceforth B) and soul (henceforth S) before S and B can on their own constitute a human being or person. … For if he does not, then either concretism is Nestorian, or the Son’s assumption destroys destroys the person to whom S + B previously belonged – turning the incarnation into a bizarre form of human sacrifice. Just when S + B would on their own constitute a compose a person or a human being is a knotty issue. … [O]ne can assume that the Son ‘gets to’ S + B before S + B are or constitute persons by holding that Christ assumes S + B as a zygote, at the moment of conception.6

The reason that the incarnation did not include two people then, in Leftow’s view, is that the Logos prevented the body and the soul from working as they normally would to constitute a person, instead making it so that they constitute a person in combination with the Logos. While under normal circumstances a human person is constituted by a body and soul, the Logos made it so that this person was constituted by a body and a soul and the Logos. Had the Logos not intervened, there would have been a simply been a human person, but by throwing itself into the “mix,” as it were, the presence of the Logos caused something else to be there – containing all the elements of a human nature (i.e. a body and a soul), but being a different type of person (having a divine nature as well).7

As a footnote to all of this, I realise that Dr Leftow does not hold to a materialist view of human beings. He is a dualist in this regard (or at least, a Thomist/Aristotelian as far as I know, a view that gets called dualism (by Catholics, I add wryly), but that is another subject, touched on in my final podcast episode in the In Search of the Soul series). Be that as it may, if his argument that we can hold to a Chalcedonian Christology while avoiding two persons in Christ is sound, then it can be pressed into the service of materialism about human persons combined with an orthodox Christology.8 Some have claimed that if you hold to a materialist view of human persons then you must hold to Apollinarianism – the view that Christ lacked a fully human nature. This objection is a non-starter, for it merely assumes that a full human nature requires an immaterial soul, which is simply not true if materialism about human beings is true. The opposite objection is that if a human being can be complete without a “soul,” then the addition of the logos to a human body must amount to the existence of two persons, which is Nestorianism.

The first reply to this claim is that it is a sword that cuts both ways and gives dualism no advantage over materialism. For if a human being is a body and a soul, then a body and a soul plus the logos is two people. This is the claim that Leftow responds to. The second response, beyond this tu quoque reply, is to adopt Leftow’s argument. Perhaps it is true that a human body can constitute a human being by itself, provided it comes to function in a given way (roughly similar to the way that I am functioning as I type this), but this does not justify the claim that a the presence of human body is always a sufficient condition for the presence of a human being. Just as, on Leftow’s model, the Logos may have “gotten to” the human body and soul of Jesus (let us say at the moment of conception) to prevent them from functioning as a complete human being all by themselves, it is similarly available to the materialist to claim that the Logos may have “gotten to” the human body of Jesus before it was able to constitute a human being all by itself. The result is a fully functioning human body whose life (i.e. whose timeline) was the life of the incarnate Son of God rather than whatever life it would otherwise have constituted. Any objection from an orthodox Christian as to the unknowability of how the Logos might have been “attached” to this body is appropriately met with the observation that even if the answer is that we absolutely no idea, this puts dualist and materialist Christologies on a level playing field.9

Glenn Peoples

1. I say that this is quite the wrong way to read Genesis 2:7, but I’m overlooking that for now in the interests of getting to the real point. [↩]
2. For Craig and Moreland’s explanation of their view, see William Lane Craig and James Porter Moreland, Philosophical Foundations for a Christian Worldview (Downers Grove: IVP Academic, 2003), 597-614. [↩]
3. Some dualists might blush at the admission that theirs is a view that downplays the importance of the physical aspects of a human being, but if their view is stated literally and without flinching, it is surely the view that Alvin Plantinga declares as his own:  “Now I should confess up front that I accept dualism: I believe that I and other (living) human beings are immaterial souls, minds or persons (I prefer the last), related in a peculiarly intimate way to a material body of a certain sort-a human body.” Alvin Plantinga, “On Heresy, Mind and Truth,” Faith and Philosophy 16:2 (1999), 186. [↩]
4. Similarly, consider the often used example: “The morning star is the evening star,” which is to say that they are the very same object: The planet Venus. If Venus did not exist, then neither the morning star nor the evening star would exist. If the morning star ceased to exist, then so would the evening star. [↩]
5. Kevin’s chapter in In Search of the Soul is worth reading if you are unfamiliar with this position. [↩]
6. Brian Leftow, “A Timeless God Incarnate” in Stephen T. Davis, Daniel Kendall SJ, Gerald O’Collins SJ (eds), The Incarnation: An Interdisciplinary Symposium on the Incarnation of the Son of God (Oxford: Oxford University Press, 2002), 280,281. [↩]
7. Essential to this is that either a human body and soul do not constitute a human being from conception, or else the Logos was present from conception so that as long as the body and soul of Christ had existed, they did not constitute a human person apart from the Logos. The latter seems clearly adequate, although for some reason Leftow asserts that nobody who wishes to maintain an orthodox Christology can believe that an embryo is a human being from conception – something that hardly follows from his explanation of the incarnation. [↩]
8. Yes of course I realise that this does not constitute Dr Leftow’s approval of materialism about human beings or of this use of his argument. [↩]
9. Of course this does not mean that just any materialist Christology is on a level playing field with just any dualist Christology in every other respect – just this one. A materialist Christology in which human beings are conceived of as material and the divine Logos also became a material object is not suggested (or addressed at all) here, and also a dualist Christology that clearly implied Nestorianism would be less than equal to the sort of materialist Christology discussed here. [↩]