This collection of essays had its origins in a conference that took place in Oxford in 2009 where most of the essays were first presented. However, all have been revised and many now refer to other essays in the volume. Given the common theme and the international character of the contributors, the work provides an interesting measuring gauge for the current state of discussion of the topic among analytic philosophers. Although all the contributors are concerned to defend what they see as doctrinal orthodoxy, a great range of positions and approaches is in fact represented. While Hill's Introduction offers a helpful initial charting of the terrain that follows, the work is clearly aimed at research students and above, and even then writers often assume familiarity with terms not in general use outside those involved in current debates. So even in article titles are to be found terms such as ‘compositional christology’ and ‘vehicle externalism’, while one complete title runs as follows: ‘Should concretists part with mereological models of the incarnation?’ Nonetheless, it is worth persevering.

Three of the contributors could be described as defending a traditional Thomist approach. Richard Cross uses his knowledge of Scotus on causality to produce a more developed account of what might be meant in speaking of Christ's human nature as the instrument of God the Son. Brian Leftow provides the opening contribution, in which he suggests we think of God the Son having no human parts but becoming a whole with them (the compositional approach). However, in order to avoid attributing materiality to the Son he suggests that, rather than thinking of a soul–body composite as he believes other human beings are, uniquely in this case we adopt a Platonic model for the soul: ‘the doctrine of the incarnation is that GS becomes fully human, not that he becomes exactly our sort of human’ (p. 29; cf. p. 44). The motivation for this is to ensure that all the traditional divine attributes remain intact even as humanity is attributed to God the Son. Ironically, however, it is Oliver Crisp who brings out most clearly that aim of the compositional approach in treating the humanity as an instrument: ‘ironically’ because his article ends by declaring that his aim has been merely to defend the coherence of the model, not necessarily to suggest that it is the right approach. While noting that the relation is especially difficult for someone like Leftow who includes atemporality among the divine attributes (p. 61), he too finds it important to stress that the relation to the human nature is ‘accidental’, to avoid any suggestion of change impacting on the divine (p. 49). A number of objections to the model are considered, including Thomas Senor's that Nestorianism (two persons) is the result. Crisp correctly replies that talk of uniting to a human nature is not at all the same thing as uniting to a human person. There is only one subject, who uses two other substances, the human mind and brain (p. 65). But he fares less well with the insulation objection (the divine nature is unaffected by the human). Technically, human predicates can of course be applied to the whole, but as medieval analogies of a garment or Leftow's of a diver's drysuit suggest, it looks as though there is no real, deep involvement with human nature.

That being so, it is fascinating to observe that such ‘insulation’ is one of the elements that lead Thomas Flint to critique the compositional (or mereological) account. In the end he believes that its value lies more in being a powerful metaphor, and he urges the adoption of more than one model to illuminate what the incarnation might mean (pp. 83, 86). However, neither he (except very briefly) nor anyone else in the volume pursues that strategy. Nineteenth-century kenotic approaches at least avoided any suggestion that the humanity was a mere instrument, granting instead a complete self-regulating human consciousness to Christ. To those who insist that all the key divine attributes are essential and the divine therefore incapable of change, such kenoticism is of course a non-starter. There is no essay defending the simplest version that was found in Gess of God the Son literally becoming human and then divine again at the resurrection. Stephen Davis, however, does offers a variant on his longstanding support for Thomasius's reduction of powers, whereas Thomas Senor attempts a version that also draws on insights from other incarnational models not necessarily kenotic. In particular he draws back from any understanding of the attributes of divinity that are abandoned as a matter of ‘having that property unless it has been freely given up’, objecting especially to the ad hoc character of such a description. In its place he wants to adapt for discussions of God Thomas Morris's two-minds approach, which treats humanity as a natural kind and so able to allow unusual properties to supervene on ‘mere’ humanity. Instead of Morris's own treatment of the divine attributes as an essential cluster concept, Senor suggests divinity might be treated as a sort of ‘a supernatural kind’ under which some divine properties might be seen as derivatively essential whereas others could operate with a ceteris paribus clause (p. 108). While theologians have long been content to talk of the discovery of divine attributes through revelation, it is surprising to find a philosopher abandoning a priori definitions, not least as he seems to offer us the substitution of one type of ad hoc approach by another. On that ad hoc test at least, the third version of kenosis that was canvassed in the nineteenth century and which came to dominate much Anglican thought in the twentieth (e.g. in Gore and Quick) looks more promising. According to the Danish theologian Martensen we should think of two aspects of divine consciousness in the incarnation of the Son, one kenotic and the other not. In other words, only part of the divine mind would live occluded from his usual full omniscient awareness, and as such the single being that is God the Son would remain omniscient despite what was being experienced by part of his identity.

Kenosis is scarcely the only way in which an attempt might be made to revise the more traditional Christological picture. Yet, surprisingly, while there are a few essays exploring more radical options, little attention is devoted to more moderate revisions of Chalcedonian Christology. So, for example, Morris's two minds approach is only discussed in any detail by Senor as he moves towards a kenotic position. The only exception is Richard Swinburne's contribution, in which he argues that his own revisions are compatible with Chalcedon. Instead of God the Son configuring the soul and body of Christ as the principle of individuation, he suggests we think of Christ's human soul as ‘merely a set of properties, a human way of thinking and acting instantiated in the second person of the trinity’ (p. 160). Presumably his motivation is to better guarantee a unified personality. Yet in order to retain both divine and human attributes he quickly resorts to appeals to Freud and how he ‘helped us see how a person can have two systems of belief to some extent independent of each other’ (p. 162). The appeal, though, is odd since Freud so often identified such divided minds as damaged. Might not some reference to Jung or others who take a more positive view of the role of the unconscious have made more sense? Then again, the insistence on logical guarantees to ensure that within such a divided mind the human could still do no wrong leads to such a strong sense of this particular human failing after all to share in the kind of challenges that ordinary humans face that towards the end of his essay Swinburne introduces a different sort of temptation to which Christ might legitimately be made fully subject: the temptation not to perform supererogatory acts. The examples he gives are the specific actions involved in the temptation in the wilderness as distinct from actually worshipping the devil. But can such a sharp distinction really be drawn? Turning a stone into bread would have been just as much a demonstration of lack of trust as the more explicit worship, even if clearly less wrong. It is perhaps therefore significant that in the only essay specifically to address the question of the rival merits of a two-minds approach versus that of a single mind, Joseph Jedwab rejects not only a two-spheres approach but also a divided mind of the type advocated by Swinburne. Instead, he suggests that we think of ‘one sphere of consciousness, one part of which is, in itself, typical of a human conscious life in our present condition and the other part of which is, in itself, as typical of a default divine conscious life as being human in our present condition allows’ (p. 182). He then uses ‘utilization syndrome’ to illustrate how the Son might continue to sustain the world even as he fails to introspect that he is so doing.

The three remaining essays cast the net more widely. The claims of Michael Rea's paper on ‘Hylomorphism and the incarnation’ are rather difficult to assess as most attention is devoted to creating an alternative metaphysics within which he then places the incarnation. Although called ‘neo-Aristotelian’, matter as ‘stuff’ and/or potentiality are both rejected and natures treated as fundamentally powers. The metaphysics is then developed to apply to immaterial as well as material reality, with a relation of numerical sameness without identity used to explicate the Trinity, and also the incarnation where ‘three compounds … coincide, all of which count as the same material object, … but only one of which counts as a person’ (p. 152). No shortage of questions arises: why, for instance, opt for this type of metaphysics rather than another; whether even to talk of ‘the relation between the persons of the Trinity as analogous (his italics) to the relation of material constitution’ (p. 148) is already to fall foul of traditional patristic objections that a further substance has now been introduced; or whether it is acceptable consequence that all angels are the same angel (p. 147, fn. 21). Robin Le Poidevin examines Brian Hebblethwaite's contention that multiple incarnations are logically impossible because an incarnation requires numerical identity. He responds by exploring several options, among them the option of making sense of the notion through the idea of ‘distributed persons’ occupying more than one body. Anna Marmodoro invites us to think of the incarnation as bearing some parallels to the way in which a human mind can extend into something other than itself, a phenomenon explored by Clark and Chambers quite independently of any religious issues in respect of the use of computers. Ontological entanglements can work both ways with the human subject sometimes experiencing a clear level of dependence if certain forms of knowledge are to occur. Even the transfer of sensation into a different medium might be possible, as in Marmodoro's example of television cameras being used to activate tactile sensations in the blind. All of this is of course highly speculative, but it is encouraging to see that the search for new analogies for what occurred in the incarnation is not at an end.

As my difficulty in attempting to interrelate these essays amply illustrates, the contributors approach philosophical issues raised by the incarnation from a wide range of different perspectives. Readers' ease of comprehension would have been greatly facilitated if contributors had been paired and asked to interact directly with one another. Again, while professional philosophers will no doubt find the essays fascinating, this book will be hard work for theologians, not least because terminology tends either to be simply assumed or else at the very least is very quickly put to use rather than being gently introduced. Yet, even with these faults, it is a valuable collection.