The blog of Dr Glenn Andrew Peoples on Theology, Philosophy, and Social Issues

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

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.

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

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…

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. []


Comic Relief: The evangelical bunker


Nuts and Bolts 016: The Root Fallacy


  1. When you’re a hammer, everything looks like a nail.

    I’m a progr(h)ammer, and everything looks like software.

    I just had an idea. The Logos is a subclass of the human superclass. That solves the problem of two persons, only one person object is instantiated, and it inherits all that is human but is more than human. No, scratch that idea, it isn’t going to work. I see that. But I just had another idea. The Logos class implements the human interface. That might work.

  2. “I just had an idea. The Logos is a subclass of the human superclass.”

    No. The Logos exists independently of whether or not humanity exists.

    “The Logos class implements the human interface.”


  3. Hilary Butler

    And when a person is a theologian, everything is an argument. But that’s not so with God.

    When God said that “we” will make man in our image, He did just that. God’s image is three, The trinity BODY, which is God the whole, inside which is the SOUL( and Word), which is JESUS, and inside those two, the Holy Spirit, which is the collective spiritual will of God and Jesus which meshes all three and can go anywhere and act as a messenger…., or as the New Testament states, “the mind of Christ” (more later).

    Adam’s BODY was created out of earth, with a unique SOUL and God breathed into him, SPIRIT.

    So while Adam had all three parts of the likeness of God, the FULFILLMENT of God’s purpose, required Adam make a personal “choice” to either believe God and live with him in order to mesh all three, or be independent of God and believe that Satan’s words that eating the apple would make him superior to God.

    Eve, then Adam, chose to believe Satan not God, and at that moment, the “spirit” part of them died (though it revived to a degree after the birth of Seth).

    To God the principle of freedom of choice is crucial.

    Forced human love, can’t happen. Likewise, what would be the point of El Shaddai “forcing” people to love HIm?

    Therefore, Adam had to make a choice, which resulted in the spirit connection to God being cut off, and his spirit becoming “darkened”.

    From that point on, in the Old Testament, while people like Enoch,, Abraham, Moses, King David etc, could listen to God and by their own choice, activate the spirit part of themselves, there was still a sense in which the “spirit” part was tainted. The potential for trinity fullness was flawed.

    Therefore, Jesus came down to earth, in the same manner in which most people do, other than God’s DNA replacing the man’s DNA.

    Jesus had a body, and his unique soul, with a spirit partially activated. He grew in wisdom and stature and amazed the religious teachers at the age of 12, but it wasn’t until he was 30 and was baptised by John the Baptist that his “spirit” part was fully activated by God implanting the WHOLE of the Holy spirit into him.

    At that point, Jesus became fully functioning in God and only did was he SAW God do and say to do. That is what enabled him to do what he did.

    After Jesus rose from the dead, and returned to the disciples in the upper room, what was the first thing he did?

    As God, Jesus and the Holy Spirit in one, .. Jesus BREATHED into the disciples (John 20:20), forming a new spiritual covenant. This breath was a new and different “breath” from the one Adam received…, so that all who believed in home could have a new spirit – not the same spirit that was breathed into Adam – a spirit which should they believe in it, would be far more powerful than anything that anyone in the Old Testament had. And enabled the apostles to ACT – hence the “acts” of the apostles. Not the intellectual “beliefs” of the apostles.

    The problem with people who want to argue about what a human person is, from an intellectual point of view is that they MISS the key.

    For example, take Ephesians 3:20. Theologians often quote…. “Now until him that is able to do exceedingly abundantly above all that we ask or think…” …. conceding that God can do anything – way more than we ask or think… which leaves God as some distant intellectual concept who can, but who doesn’t. After all, if God did, the world wouldn’t be in the mess it is in today.

    The bit theologians miss, is the “new breath”.

    In order to become what jesus said we could become if we choose…., and become that NEW creation and be born again, the “breath” in you has to be the new testament breath, from Jesus – the Holy spirit – not the Old testament breath, which only wants to obey a set of rules and laws, and add to them and take away from them, as it is expedient to do so.

    When a person has been breathed on by Jesus, then Ephesians 3: 20 becomes this:. “Now until him that is able to do exceedingly abundantly above all that we ask or think ***ACCORDING TO THE POWER THAT WORKS IN US*** ”.

    And when you have that POWER working in you, ONLY THEN ….. God is able to do exceedingly abundantly, because you no longer think through “Adam’s” eyes, that ONLY what you see, hear, feel smell and taste is relevant. there is a difference between “natural” truth and “spiritual” truth, well exemplified in 2 Kings chapter 6. What you see with natural eyes, isn’t what you CAN see through spiritual eyes, if you allow them to be opened.

    The key, to opening the spiritual eyes, as it was with Adam, is that word “CHOOSE”.

    Deuteronomy 30:19 still applies. “Look, I call heaven and earth to record against you this day that I’ve set before you life and death, blessing and cursing, therefore choose life.”

    YOU choose.

    And when Jesus breathes into you, you KNOW, and don’t need to waffle around intellectual corridors, because the POWER that is within you (John 14:26 and 12 John 2 : 27) , gives you all the answers which your old intellectual “mind” couldn’t work out. You need no human to teach you.

    Why can’t the philosophers work it out?

    Because they are trying to work it out with their natural minds. 1 Corinthians 2 : 14 “The person without the Spirit does not accept the things that come from the Spirit of God but considers them foolishness, and cannot understand them because they are discerned ONLY through the Spirit.”

    So theologians waste hours arguing about concepts which – were they to choose life, and ask Jesus into their lives, – would become crystal clear.

    However, the problem for them, is that it’s still very hard to explain what is crystal clear to a natural man, because again, what is so simple, is considered “foolish”.

    A human being does indeed require a rational “soul”.

    A soul is comprised of the WILL, mind and emotions, and it’s the human soul, the human PERSONALITY which is the “trigger switch” and which has to make THE CHOICE.

    Without having a unique, “one-of-a-“kind, personal soul, which is different to every other soul in the world, the concept of choice is made null and void. We have to chose to allow Jesus to renew our minds, so that we understand this new spirit, the “mind of Christ” Jesus breaths into us.

    And that’s why God will metaphorically defend a person’s choice to go to hell.

    Love cannot be dictated.

    A relationship can’t be mandated.

    True service can’t be forced.

    Heart felt worship can never happen through gritted teeth.

    Anything done for any other motive is hypocrisy, which is why Jesus had such hard words for the intellectual leeches – the Pharisees and Saducees of his day, whose sole focus was to USE God for their own ends, while leaving the whole foundation of what God was saying completely out of the equation.

    to be continued:

  4. Hilary Butler


    Jesus would say no less today, to those who have a form of godliness with lofty words, and argumentative concepts, yet deny the power of God because they don’t understand or have a clue what “the spirit” is, in the first place.

    God’s idea of a fully functioning human person, is a body, a unique soul, and a spirit – preferable the breath of Jesus. A human can have another “spirit” (Luke 9:55) but that’s not the ideal spirit, is it?

    But without the natural man choosing life, and being breathed into by Jesus, a human remains a “natural” man, and that is all.

    So yes, a “human” can comprise just a body and a soul and that is sufficient condition for earthly existence.

    But that isn’t the existence that God wants us to chose. God wants us to chose life, and life more abundantly. And to do that, a person has to really understand Body, Soul and Spirit the way God means it, which is in the IMAGE and LIKENESS of God.

    It’s simple really, but foolish to the natural man.

  5. Interesting argument, Hilary. You may in future want to be a little more accepting of people who use arguments. 🙂

  6. Nathan

    LOL @Richard. Very funny!

    It would be an entertaining exercise to try and define Logos and Human as classes, and then try and bring them together to get incarnate Jesus, but ultimately it won’t work.

    Jesus will always be in a class of his own, but even that statement is saying too much… 😉

  7. Roy

    Hi Hilary

    I’m not sure you have Glenn enough credit for his exegetical abilitie, particularly in light of some of your non-biblical comments (eg Adam didn’t eat an apple; God breathed into Adams corpse and he became a living soul.

    Anyhoo check out

  8. Bengt Ödman

    Defining the incarnation in object oriented programming terminology is something that I also have thought about. The interesting thing is getting both the incarnation and the trinity right. Incarnation inherits from interfaces Son and Human, God inherits from Father, Son and Spirit. So far, no problem. But then, both Human, Father, Son and Spirit inherit from Person. Now we have the “diamond problem” – which person does Incarnation inherit – the human one or the Son’s? (non programmers, see

    But perhaps the answer is simply: the Son’s. Whatever being human implies, it does not matter which person you are. This is analogous to Glenn’s reasoning above about the soul. If we let “soul” mean just “person”, or perhaps better “agent”, is there a problem about the incarnated Christ having the son’s personhood? Isn’t this exactly what we want to affirm? (I’m aware that I’m somewhat mixing classes and instances, I’ll try to do this more strictly when I’m not supposed to be working (programming)).

  9. > I’ll try to do this more strictly when I’m not supposed to be working (programming)

    Bengt, be sure to keep us posted.

    Woot, woot! OOT. 🙂

  10. So I Googled the phrase “object-oriented theology”.

    About 33,100 results.

    Not sure if namespace collision or Ecclesiastes 1:9.

  11. Nathan

    > I’m aware that I’m somewhat mixing classes and instances

    Yah… exactly why it won’t work. Fun nonetheless 🙂

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