This is an essay in defence of a compositional view of the incarnation. According to the compositional view defended here the second person of the Trinity, the eternal divine Son or Logos, adds to himself as a part a human body–soul complex and in so doing becomes the incarnate Christ. Such a view presents itself as a natural, and initially plausible, reading of the Chalcedonian formula which holds that Christ comprises two natures in one person. In addition, it offers several other advantages. Nevertheless, this compositional view has been the target of serious criticisms, criticisms which have led several recent writers to conclude that we need to look farther afield to find an acceptable view of the metaphysics of the incarnation. In this essay I shall provide a careful statement of the view as well as an enumeration of the advantages it offers. I shall then consider the main objections that have been raised against the view, and suggest answers to those objections. In the process, I shall offer reasons for rejecting another sort of compositional view, one that some thinkers have thought superior to the one under consideration here.

Since there is more than one compositional view of the incarnation, it will be useful to have a name that picks out the one under discussion. Following Thomas Flint, I will term this version of the compositional view ‘Model T’, in deference to its (somewhat tentative) adoption by Thomas Aquinas.Footnote ¹ Flint, with characteristic wit, also connects ‘Model T’ with Henry Ford; he implies that this venerable early model has become mechanically (or rather, metaphysically) unreliable and should now be replaced by more up-to-date versions. Whether this verdict of philosophical obsolescence should be sustained is one of the things we need to consider.

Model T is a concrete nature model of incarnation. We are told that Christ is one person with two natures, but how are these ‘natures’ to be understood? In contemporary philosophy natures are most commonly considered as abstract: a ‘kind-nature’ comprises all the properties that an individual must possess in order to qualify as belonging to the kind in question. This usage existed in ancient and medieval philosophy as well, but there was also a sense of ‘nature’ according to which a nature is concrete: it is the concrete ingredient in the metaphysical makeup of an individual that makes it the sort of individual that it is. Concrete-nature models of the incarnation take it that Christ's human nature is a nature of this sort: it is a concrete instance of humanness – what some modern views would term a ‘trope’ of humanity – which the eternal Son united with himself in order to become human, one of us. This nature was understood as consisting of Christ's human body and soul; I shall sometimes refer to it as the ‘body-soul complex’. (Concrete-nature views are however compatible with a considerable range of mind–body theories; they can accommodate Platonic dualism, Cartesian dualism, Thomistic dualism, emergent dualism, and many varieties of non-reductive materialism.) Abstract-nature models, in contrast, consider Christ's human nature to be an abstract universal; it is the set of properties which came to characterize Christ when he became human.Footnote ²

Or is this a distinction without a difference? Brian Leftow has suggested that it is; he writes:

Leftow's remarks here need to be carefully interpreted. Some abstract-nature views affirm that Christ came to possess the full set of essential human attributes without thereby ‘owning the full human natural endowment’, if by that is meant having a body and a soul that are produced in the ordinary way that is normal to human beings in general. Specifically, these views hold that Christ's divine nature either took the place of a human soul, or actually became such a soul, and thus he became fully human without possessing a human soul produced in the normal way, whatever exactly that way may be.Footnote ⁴ Leftow, I think, would still want to say that on such views Christ owned the full human natural endowment, and thus did ‘acquire the property of being human’. This, however, involves a rather broad interpretation of what it is to have a concrete human nature. But even if we were to agree with Leftow that abstract-nature incarnation occurs if and only if concrete-nature incarnation does, there would still be the question about the right way to understand ‘nature’ as it occurs in the various christological formulas.

There are several considerations that speak in favour of the concrete-nature view. Such a view clearly enjoys the majority support of traditional Christian theology: according to Oliver Crisp, ‘most of the Fathers and the medieval schoolmen’ held that ‘a human nature is not fundamentally a property, but a concrete particular composed of a human body and a distinct soul’.Footnote ⁵ Furthermore, this seems by far the most natural way to understand the Chalcedonian formula, the touchstone of christological orthodoxy. Note in particular the famous series of prohibitions: Christ is ‘made known in two natures, without confusion, without change, without division, without separation.’Footnote ⁶ On the concrete-nature view, it is fairly clear what is being ruled out here. The problem for the abstract-nature view is not so much that if the natures are understood abstractly these prohibitions would be violated. The problem lies, rather, in understanding in any coherent way what it is that is being prohibited if the two natures are considered as abstract. Abstract natures are by definition unchanging, and on the other hand the natures of God and of human beings are distinct, and therefore ‘separate’, if any meaning can be attached to the word in this context. So at least it seems to me; friends of the abstract-nature view are invited to propose their own plausible and natural interpretation of the prohibitions. Furthermore, there is a strong case that, in the doctrine of the Trinity, the divine nature or ousia is understood to be a single concrete nature that is shared by the three Persons;Footnote ⁷ the parallel in terminology between the doctrines of Trinity and incarnation argues for a concrete interpretation of Christ's human nature as well.

Another difficulty urged by Crisp is that existing abstract-nature views (those that embrace abstract-nature incarnation without concrete-nature incarnation) imply monothelitism, the view that there is in Christ only a single will. Now, some moderns might well consider this an advantage rather than a disadvantage. It is a fact, however, that monothelitism was condemned, and dyotheletism affirmed, at the Sixth Ecumenical Council, which met in Constantinople in 680–681. Furthermore, dyotheletism has been affirmed by major theologians of all the main Christian traditions, including Protestants for whom the Sixth Ecumenical Council may not be fully authoritative.Footnote ⁸ Embracing monothelitism may be an option, but adopting that option involves a major deviation from the mainstream tradition of orthodox christology.

These considerations may well fall short of a conclusive case in favour of the concrete-nature view. I would maintain, however, that they give us good reason to consider seriously such a view, and to realize that abandoning it comes with some serious costs. And there is at least one additional major potential advantage of the concrete-nature view, an advantage which, if it can be sustained, may turn out to be decisive in the view's favour. One of the problems confronting the doctrine of incarnation – some would consider it the most serious problem – is what might be termed the ‘attribute problem’ – the problem, that is, of reconciling the apparently inconsistent attributes the doctrine requires us to ascribe to Christ. He is present throughout the universe, yet for thirty years he was confined to a small area of Palestine. He knows all things, yet he is limited in knowledge and on some points was actually in error – and so on. For lovers of paradox these contradictions may be welcome, but for a theologian or philosopher intent on arriving at a rationally coherent understanding of the incarnation they are troubling. Now a rather natural thing to say here, and that has often been said, is that (for example) Christ is omniscient qua God, but limited in knowledge qua human being. But then there is a need for understanding the qua terminology, and it is not clear that this terminology can give us what we want. If being omniscient qua God just is a way of being omniscient, then ‘Christ is omniscient qua God’ entails ‘Christ is omniscient.’ Similarly, ‘Christ is limited in knowledge qua human being’ will entail ‘Christ is limited in knowledge’, and now we have our contradiction back again full strength; the qua move has accomplished nothing.

It has occurred to a number of writers that what is needed at this point is some way to segregate the apparently contradictory attributes, so that they do not need to be attributed, in the first instance, to literally the same subject. And what makes this possible, in general, is that a whole can ‘borrow’ attributes from its parts, even when there are there are other parts to which those same attributes do not apply. An apple is red because its skin is red, even though the flesh of the apple is not red at all. And on the other hand, the apple is nutritious because its flesh is nutritious, even though the skin, composed almost entirely of cellulose, contributes little in the way of nutrients. Just here is where the distinct parts of Christ, as featured in the concrete-nature view, can be of service. Clearly the omniscience is in the first instance attributed to his divine mind, and in virtue of that to the divine-human person as a whole. The limitations in knowledge, on the other hand, are those of the human mind and soul of Christ, so that he is truly said to be so limited even though his divine mind suffers no such limitation. This will, no doubt, leave us with some difficult questions about the relations between the two natures, and in particular between the two minds in Christ. But we do seem to have solved the problem of contradictory attributes.

Richard Cross, however, has questioned the viability of this solution. He writes:

Cross raises important points, but the advocate of the concrete-nature view is not without resources for a reply. First of all, as noted previously, the traditional orthodox doctrine of the Trinity understands the common nature as being concrete, rather than abstract; it is the identical concrete nature that is shared between the divine persons. Now, one may very well ask how this is possible, and answering that question may prove to be a challenge for the trinitarian. Nevertheless, when we are undertaking to expound the doctrine of the incarnation in the light of the doctrine of the Trinity I would suggest that it is this traditional doctrine that we need to have in mind – unless, of course, we have repudiated the traditional doctrine of the Trinity and elaborated a version of our own that we propose to substitute for it. Cross may, perhaps, have had some such replacement in mind, but if so he is far from explicit about how we are to understand it.

But there is a second reason why Cross's objection fails to be decisive: it supposes a parallelism between the roles of the human nature and the divine nature which does not in fact obtain. Are we to imagine, as he suggests, that a divine person ‘borrows’ divinity from the divine nature? If we were to imagine this, the question would arise, ‘Who or what does the borrowing?’ Not, one assumes, a nature-less bare particular! But of course, this is misconceived. The divine person has no need to borrow divinity; the divine person already exists, from all eternity, and his existence is inseparable from his possession of the divine nature. Eleonore Stump, in a passage quoted by Cross, points to ‘a distinction between a property a whole has in its own right and a property it has in virtue of having a constituent that has that property in its own right’;Footnote ¹⁰ it is only the second sort of properties that are said to be ‘borrowed’. Undoubtedly, Stump would consider divinity to be a property that a divine person has in his own right. The borrowing that does occur is done by the divine person, as he takes to himself attributes which, in the first instance, are attributes of the human nature – of Jesus’ body, mind, and soul – attributes he would not have in virtue of the divine nature alone. I believe, therefore, that Cross's objection fails, and that the concrete-nature view really does provide us with a solution of the incarnational attribute problem. Furthermore, this is arguably the best solution that is available, or even possible. If there are not in Christ diverse natures to which the conflicting attributes can in the first instance be assigned, it seems that the only way to avoid the contradiction is by either modifying or rejecting altogether the attributes in question. Kenotic christology provides a clear example of this, by either rejecting or modifying almost beyond recognition some characteristic divine attributes during the time of Christ's earthly life. I would argue that the solution to the attribute problem provided by concrete-nature theory is much superior to solutions which reject some of the relevant attributes, or modify them in major ways. If so, that is a strong argument in favour of the concrete-nature theory.

We shall proceed, then, on the basis of a concrete-nature understanding of the Incarnation. But the model being expounded, Model T, also says something specific about the way in which the natures are united: it says that they are united in virtue of the divine Son's adding to himself the human nature – a human body-soul complex – as a part. This, however, has seemed objectionable, even to some who are happy with a concrete-nature understanding of the doctrine. So we need to consider these objections, beginning with some posed by Brian Leftow. Leftow is strongly averse to the idea that a divine person can in any way include something material as a part.Footnote ¹¹ Some of his arguments for this are exegetical: God the Son said that God is a spirit (John 4:24), but a spirit by definition has no material parts. So at the moment when Jesus said this, he both had material parts (according to Model T), and implied that he had no such parts. To the suggestion that in this text ‘God’ refers to the Father, Leftow replies that ‘GS spoke of the Father as Father quite freely, and so when He uses “God,” not “Father,” plausibly He means to refer to God, not the Father . . .’Footnote ¹² Furthermore, the Bible insists that no one has ever seen God, but if God the Son has a visible part, then quite a few people have seen God.Footnote ¹³

It is difficult to see much force in these arguments. Leftow's exegesis of John 4:24 strangely ignores the immediate context, which reads like this:

It is clear enough from this that Jesus is referring to the God of Israel, whom he knew as Father. It is unfortunate for Leftow's interpretation that the New Testament never uses ‘God’ to refer to the Trinity – a fact to which unitarians point with great satisfaction. Nor is ‘God’ used to refer indifferently to any of Father, Son, and Holy Spirit. (It really is not helpful to appeal to the usage of ‘God’ by contemporary trinitarians as a basis for interpreting the New Testament.) There are a few (but crucially important) texts in which Jesus is called ‘God’; otherwise, ‘God’ refers to Yahweh, the God of the Hebrews, whom Jesus knew and proclaimed as his Father. But as for Jesus as a ‘pure spirit’, consider Luke 24:39: ‘See my hands and my feet, that it is I myself; handle me and see, for a spirit has not flesh and bones, as you see that I have’ (RSV). To be sure the ‘spirit’ here is not a divine person but rather a ghost – but the positive assertion is that Jesus, the Son of God, does have flesh and bones and can be seen and handled. This seems to say of Jesus precisely what Leftow wants to deny – that his bodily parts are really him, really Jesus himself. The argument about visibility loses almost all of its force once Leftow admits, as he is forced to do, that we can indeed see God indirectly, by seeing Jesus. And consider this text: ‘No one has ever seen God. It is God the only Son, who is close to the Father's heart, who has made him known’ (John 1:18, NRSV). Here it is precisely because the Father cannot be seen that a Revealer is needed – and it is because the Son, who is also divine, can be seen that he is uniquely qualified to be that Revealer.

Also of interest here is Leftow's ‘body snatching’ objection. Leftow assumes, not implausibly, that if Jesus’ body and soul had come into existence without being assumed by a divine person, there would have been a human person that would have been either identical with or constituted by that body–soul complex. But if this is so, ‘there is a person there who would have been from the beginning in this body but for the Incarnation. . . . So GS turns out to have been a body snatcher, robbing this other of his chance at life.’ He then asks, ‘Should one hold a view of the Incarnation that makes it in any respect morally questionable?’Footnote ¹⁴ Indeed, the notion of the Son as a body snatcher is quite unappealing. However, Leftow makes a fallacious inference. He first asserts, in effect:

From this he infers:

But this doesn't follow; what we have here is a quantifier-shift fallacy. The fact that under certain conditions there would have been a person of a certain sort in no way implies that, as things stand, there actually is such a person. So the correct conclusion is that, as a matter of fact, there is no such person, and therefore no one to be the victim of the alleged body-snatching.

There is something else that Leftow says that gives us some insight into his views on these topics. He writes:

Notice, however, that there two different ways in which an immaterial thing could become partly material. One way is that part of the immaterial thing could change into something material. Perhaps Leftow is right in deeming this impossible. The other way, is that the immaterial thing could have added to it a part that is material, and that does not seem so obviously impossible. In fact, widely held views concerning eschatology imply that this actually happens in a large number of cases. Suppose, to begin with, that humans are body–soul compounds (not souls alone).Footnote ¹⁶ At some point, the body perishes; the person then enters into an ‘intermediate state’ in which he or she exists unembodied. At the resurrection, the person is once again clothed in flesh; it is once again a material-immaterial compound. This seems to be a clear and straightforward case of an immaterial thing (the unembodied person) becoming partly material through the addition of a material part.

We turn now to a pair of somewhat similar objections put forward by Thomas Flint and Robin Le Poidevin.Footnote ¹⁷ In each case we begin with a puzzle from general metaphysics, which is then applied to the incarnation so as to present a problem for Model T. We begin with Flint's argument, which he presents as a special case of ‘a standard objection to mereological increase, sometimes called the growing argument, that is difficult to handle for mundane cases of substances gaining parts and, as I see it, even harder to handle in the case of Model T’.Footnote ¹⁸ He states Model T as follows:

With regard to our understanding of D, Flint proposes that we

Flint refers subsequently to D as the ‘divine-substance-plus-whatever’. He points out that since the incarnation is a contingent event, we can contrast a world Y, in which incarnation occurs, with a world N, in which there is no incarnation. Given this machinery, he presents his argument as follows:

1. (1) W in Y = W in N.

This seems correct, because the same Son or Word exists in both of these possible worlds. But we can also assert:

1. (2) W in N = D in N.

This is so because ‘In worlds such as N . . . there are no parts to compose the Son other than the divine-substance-plus-whatever. In such worlds, then, it seems that the Son must be simply identical with D.’Footnote ²¹ Furthermore,

1. (3) D in N = D in Y.

D is itself a necessary being; it exists whether or not the Son becomes incarnate. But now we can infer:

1. (4) W in Y = D in Y.

‘But,’ Flint says, ‘(4) is clearly lethal to Model T. For that model insists that the incarnate Son is a composite being, one who is not identical with D, but rather has D as a proper part.’Footnote ²²

How might the friends of Model T respond to Flint's argument? The best response, I think, is to focus on premise (2) of the argument, which states that in the no-incarnation world N, D, the divine-substance-plus-whatever, is identical with W, the divine Word or Son. Is this premise true or false? If we suppose that (2) is false, it follows immediately that Flint's argument is unsound, and as such it can pose no threat to Model T. Suppose on the other hand that (2) is true. (Flint's argument in support of (2) will no doubt strike many as persuasive.) If so, it follows immediately that (4), the argument's conclusion, is true as well. (Identity does not vary across possible worlds.) This, however, poses a problem for Model T, as indicated by Flint's remark, ‘the incarnate Son is a composite being, one who is not identical with D, but rather has D as a proper part’. This remark spells out what was implied by Flint's earlier statement, in explaining Model T, that the ‘Son . . . combines both his original, divine substance (D) and his created human nature (CHN)’. Here it is apparent that the divine substance does not add the human nature to itself as a part; rather, the divine substance and the human nature are distinct elements in the composition of the Son. This, however, immediately implies that the Son and the divine substance are not identical, as asserted by (2). This is because Model T asserts that the Son does add the human nature as a part of himself, whereas the divine nature does not (and presumably cannot) do this. So we see that (2), far from being implied by Model T, actually contradicts that model; instead, we are forced to assert that (2) is false, in spite of the fact that the Son has no parts in addition to the divine nature.

To be sure, Flint's argument may still raise puzzling questions. For instance, it might lead us to ask, what is the relation between D and W, given that it is not identity? My own preferred answer to this question is that D constitutes the Son, but is not identical with the Son; spelling this out, however, must await another occasion.Footnote ²³ But as an objection to Model T, the argument does not succeed.Footnote ²⁴

Le Poidevin's objection is introduced with a ‘tale of a tail’.Footnote ²⁵ The protagonist of his story is Tibbles, a cat. There is, however, also Tib, which consists of all of Tibbles except for his tail. Tib is not, of course, a cat, but rather a proper part of a cat. And Tib is obviously distinct from Tibbles: the latter, but not the former, is a cat with a tail. But then an accident occurs, and Tibbles loses his tail. This is a misfortune for Tibbles, but it also changes the status of Tib. Tib, it seems, is no longer a mere proper part of a cat; rather, Tib is ‘all the cat there is’ in that region of space, and there is no longer any reason to deny that Tib is a cat. Tibbles, however, still exists: the accident was not fatal. But now it seems that Tibbles and Tib are identical, whereas before they were distinct. (If we think they remain distinct, we now have two exactly similar cats occupying the same region of space. We will have multiplied cats by subtracting a tail, which seems impossible.) This is a puzzling situation, to say the least.

And now we are ready for Le Poidevin's argument. It is stated as follows:

1. (a) The pre-incarnate divine nature = the incarnate divine nature (since nothing intrinsic has happened to it).

2. (b) The pre-incarnate divine nature = the Second Person of the Trinity (since the three members of the Trinity exhaust its composition, and nothing else is divine, so only the Second Person of the Trinity could be identical to the divine nature, given that neither the Father nor the Holy Ghost become incarnate).

3. (c) The Second Person of the Trinity = Jesus Christ (since Christ is the Son made man).

From (a), (b), and transitivity:

1. (d) The Second Person of the Trinity = the incarnate divine nature.

From (c), (d), and transitivity:

1. (e) Christ = the incarnate divine nature.

But (e) is false, as the divine nature is only part of Christ.Footnote ²⁶ Le Poidevin states: ‘This is, in structure, precisely the same paradox as the one concerning Tibbles: both involve identity statements, from which is derived a further identity statement, x = y, which conflicts with the previously established truth that x is merely a proper part of y.’Footnote ²⁷

This is undeniably ingenious, but in order for it to pose a problem for Model T the premises must be ones that an adherent of Model T would accept, or would be unreasonable not to accept. This requirement is satisfied in the case of (a) and (c); standard accounts of Trinity and incarnation will typically accept both of these premises. (b), on the other hand, is problematic in the extreme. Is it the case also that each of the Father and the Holy Spirit is identical with the pre-incarnate divine nature? This would lead to the conclusion that each of the Persons is identical with each of the other two, which is the heresy of Sabellianism. In any case, this interpretation is ruled out by Le Poidevin's explanation of the premise. Are Father and Spirit, then, devoid of the divine nature? Or does each have his own divine nature, distinct from that of the Son? This would contravene the assertion, intrinsic to trinitarian doctrine, that there is a single divine nature which is the nature of all three Persons. (Le Poidevin's references to Stump and to Aquinas, both of whom affirm a single concrete divine nature, seem to indicate that he would not pursue the option of multiple divine natures.) So far as I can see, there is no interpretation of (b) according to which it would be acceptable to an orthodox trinitarian. And since Model T (and compositional Christology in general) is built on the doctrine of the Trinity, we must conclude that Le Poidevin's argument is a failure as an objection to this sort of christology.Footnote ²⁸

Refuting these objections is not, of course, sufficient to demonstrate that Model T is correct. Many, no doubt, will be left unpersuaded. (I doubt that Leftow's objection to ‘materialist christology’ will be assuaged.) So it will be helpful at this point to consider another compositional christology, one that Flint (continuing the automotive theme) has termed ‘Model A’. According to Model A, as explained by Leftow, God the Son, Jesus’ body, and his soul ‘came to compose one thing, but B + S did not become a part of GS’. This, of course, in contrast with Model T, according to which ‘B + S became part of GS’.Footnote ²⁹ An important question to ask regarding Model A is: where in the resulting situation is Jesus Christ to be found? For Model T, this is not a problem: Jesus Christ is God the Son, who has assumed the body–soul complex in such a way that it has become literally part of himself. But no such simple answer is available for Model A. The three possibilities that offer themselves are, Jesus is the body–soul complex, Jesus is God the Son, or Jesus is the whole composed of God the Son and the body–soul complex as parts. But the first of these, Jesus as the body–soul complex, can be eliminated immediately: to suppose that the body–soul complex is the person, Jesus Christ, is precisely to suppose that in the Incarnation there is a second person, distinct from God the Son. And that is the heresy of Nestorianism.

The Nestorian option having been eliminated, it seems natural to many to identify Christ with the whole having as proper parts the body–soul complex and God the Son. Oliver Crisp, indeed, simply identifies this view (which he equates with the medieval ‘habitus model’) with compositional Christology as such; he seems to overlook or ignore Model T as an option. He writes:

Since the human nature does not become part of God the Son, this approach is free from the sorts of objections Flint raised against Model T. Furthermore, the idea that Christ comes into existence as a result of the union of divine and human natures seems inherently appealing. But there is a metaphysical principle that spells serious trouble for such an interpretation. Here is the principle: A person cannot have a person as a proper part. Upon consideration, this seems evident, and I know of no one who explicitly denies it. (If the principle does not hold, each one of us may comprise a multitude of persons, one for each tiny bit of us that could be removed while leaving behind enough of what is required for personhood.) But this principle has devastating implications for this version of Model A. God the Son is unquestionably a person, nor will he cease to be a person at the time of the Incarnation. But since, on this view, Jesus Christ is the whole composed of God the Son and the human nature as proper parts, it follows that Jesus Christ is not a person. In fact, there is no person who was born of the virgin Mary, who suffered, died, and was buried, who rose again on the third day, and so on. And this, I believe, is all by itself more than sufficient reason for rejecting Model A on this interpretation.Footnote ³¹ We may well ask, If Jesus is not a person, what is he?

With these options eliminated, what remains is that Jesus Christ is identical with God the Son. This is Leftow's view (agreeing at this point with Model T), and it has some marked advantages.Footnote ³² The Chalcedonian formula refers to ‘one and the same Son, only-begotten, divine Word, the Lord Jesus Christ’.Footnote ³³ This certainly seems like an assertion of identity between all of the items thus placed in apposition. It's true, to be sure, that this identity-statement has some implications which may initially seem surprising. It implies that Jesus Christ existed from all eternity, that he is not essentially a human being, and that he would have existed even had human beings never been created at all. But this sentence can appropriately be paraphrased as follows: the person we know as ‘Jesus Christ’ is identical with the divine Son, who existed from all eternity, is not essentially human, and would have existed even if there had been no humans; in that case, however, he would not have been called ‘Jesus’, and would not have been the Christ. This explanation does enough, I think, to remove most of the air of strangeness from the original assertion.

There are other implications, however, which remain disturbing. The identity of Jesus and the Son, when combined with Model A, seems to imply that Jesus never at any time had a human body and soul as his own body and soul. At least, this would be implied if we suppose that ‘having’ a body and soul involve having them as intrinsic to one's very being. This simply was not the case with Jesus on the present view, and we are left wondering, who or what was it that agonized in the garden, and suffered on the cross? The answer to that question is far from being of merely theoretical interest!

Leftow is very much aware of this problem, and devotes a lot of energy and ingenuity to providing an answer. The problem, of course, is to establish some sufficiently close relationship between the eternal divine Son (= Jesus) and the body–soul complex that the body and soul can be genuinely his body and soul, yet not in any way a part of Jesus himself. The concept of borrowing doesn't work here; as Flint points out, wholes can borrow properties from their parts, but parts normally cannot borrow properties from other parts. (The apple is red because its skin is red, but we can't say that the core is red because the skin is red.)Footnote ³⁴ Leftow makes a lot of different moves in his attempt to persuade us on this point, and there is not space here to discuss all of them. His main reliance, however, is on a ‘Platonist’ reading of the mind–body relationship. According to Platonism, we are identical with our souls, and our bodies are not in any way part of what we are. Nevertheless, there is a sufficiently close relationship between those souls and their bodies that the bodies are genuinely our own bodies, and the actions and experiences that occur through those bodies are our own actions and experiences. Similarly, on Model A understood in Leftow's way, Jesus just is the divine Son, and the body-soul complex is no part of his proper being, yet the relationship is sufficiently close that the body and soul are his body and soul, and the actions and experiences that happen through that body and soul are his own actions and experiences.

The appeal to Platonism in this context is already suspect. For many of us, Platonism is incredible precisely because it requires us to admit that my hand, my heart, and my brain are not really part of me, the person. (This is even more problematic when it is applied, as it must be, to non-human animals. Thus, we will have frogs and spiders that are entirely immaterial; they have no material parts and are only contingently embodied!) But even waiving this general objection to Platonism, the parallel is unconvincing. With Platonism we still have the intimate and pervasive causal interaction between soul and body, something that makes it impossible to deny that the experiences had through the body are genuinely that person's experiences. This causal interaction also obtains in the incarnation, but the soul that thus interacts with the body is not Jesus, the eternal Son, but rather the created human soul – a soul that is no more a part of Jesus himself than the body with which it interacts. And unless we think of the Son as determining directly everything done by that body and soul, thus turning the body–soul complex into a puppet, we won't have the sort of detailed and pervasive control of the body's actions that obtains between the Platonist soul and its body. The sorts of considerations that bind the Platonist soul to its body just don't obtain in the incarnation.

Before leaving this topic, we need to look more closely at Leftow's own attitude towards his argument. He writes:

Here Leftow seems to be admitting that his case for Model A depends on his prior argument that it is impossible for a divine person to take on a material part. If we aren't convinced by that prior argument (as I've claimed we should not be), we ought instead to embrace the alternative that Leftow rejects – that the composite, God the Son who has taken on a human nature as a part, is a better candidate for the incarnation than the one he offers.

I have argued that Model T, according to which God the Son takes on a human nature as a part, is a coherent and plausible account of the metaphysics of incarnation. It can withstand the challenges that have been brought against it, and it is markedly superior to the main alternative concrete-nature account, Model A. Nevertheless, I am happy to agree with Thomas Flint that ‘Christians . . . should at least be open to trading [Model T] in for a better model.’Footnote ³⁶ Absolutely! As Flint rightly notes, the doctrine of the incarnation does not by any means stand or fall with Model T, and if any of the new models that are coming off the assembly lines nowadays prove to be better, by all means we should keep up with the times. But in my case, I will need to be shown that the newer models really are superior. In the meantime, me and my Model T will just keep chuggin’ down the road.Footnote ³⁷