In this work in the Oxford Studies in Analytic Theology series, Joshua Cockayne applies the tools of analytic philosophy to ecclesiology as others have already done with questions of God, incarnation and sacraments. The intent of the book is therefore not to present a comprehensive ecclesiology, but to apply analytic tools and models to bring clarity to traditional ecclesiological questions, and specifically to the question of ‘the unity, or oneness, of the Church’ (p. viii). Particularly important for this work is the analytic literature on social groups, used to illuminate and analyse a central theme that runs throughout the book: how a collective body can act as a single agent, and how the collective identity of the church should be understood in view of the individual identities of its constitutive members. As Cockayne states in the Preface: ‘The central thesis of the book is that the Church is a social body, composed of many individual members, united through the work of the Holy Spirit to be the body of Christ’ (p. xi). This ‘unity thesis’ is then expanded in the book in both conceptual and practical directions, the first three chapters focused upon the identity of the church, and the latter four chapters focused upon its activity.

Chapter 1 is a conceptual chapter that lays the groundwork for the rest of the book by addressing the relationship between individualism and collectivism. Cockayne does not choose for one over the other, finding common conceptions of individualism and collectivism overly simplistic. He opts instead for ‘a model of the Church and its oneness which assumes the truth of both holism and individualism’ (p. 19). He maintains that while individual agency is not overridden or nullified by social aggregates, individuals are deeply ‘enmeshed and intertwined in sociality’ (p. 19). Moreover, social groups are real insofar as they are not simply collections of individuals but possess a form of supervenient agency that is imposed upon the individuals that constitute them. This chapter may seem peripheral to a theological account of ecclesiology, but for Cockayne it is crucial for all that will follow, for to speak of the oneness of the church requires the ability to speak of the church as a single agential reality rather than simply an aggregate of individuals. This requires, as Cockayne rightly notes, not simply a social theory of groups but an account of the work of God to unify the church.

Thus the second chapter turns to the work of the Spirit in making the church one. Yet how should this resulting unity be understood? Cockayne recognises that there is a tension in his argument: on the one hand, ‘in many respects, questions concerning social ontology and the relationship between members and social groups are not unique to the Church’ (p. 21); on the other, the church is an entity unlike any other group precisely because it is not simply the product of natural group dynamics but the result of the miraculous work of the Spirit of God (‘the Church's unity is rooted in the work of God, not in human structures’, p. 24). Cognisant of this tension, Cockayne does not want to translate or to collapse the theological reality of the church into a form of ecclesiological naturalism. He seeks, rather, a coherent social ontology of the church that would illumine this single agency of the church, yet that would simultaneously recognise that the most important agents in the church's worship and activity are divine, namely, the Trinitarian persons. The intent is not to collapse the agency of the church into the Spirit, or the Spirit's agency into the church. Cockayne is aware of the danger of confusing the Spirit and the church as well as Christ and the church, and he also recognises that these relations must be ‘asymmetrical’ (e.g. pp. 46, 54). Yet whether these careful distinctions are clearly maintained throughout the book is a question in view of his willingness to speak of the church as an extension of Christ's agency in the world.

The third chapter, on the church as the body of Christ, addresses precisely this identity and distinction of Christ and the church while noting the correlative dangers of either confusing Christ with the church or of entirely separating them. Cockayne's own argument is that Christ's agency and embodied existence are extended in the church (and the Eucharist) in a manner analogous to how cognitive processes can be extended through external artefacts (e.g. of how a person with dementia may come to rely upon a notebook for her memory such that the notebook becomes part of her now-externalised ‘cognitive system’). Cockayne is aware that such functional arguments will not be compelling to everyone. This is no minor point, for his claim that Christ stands in ‘a relationship of metaphysical extension to the Church’ (p. 63; cf. p. 74) hinges to some degree on its explication, and functional social models of cognitive and bodily extension are the very means by which he seeks to illumine how this is might be so.

In the end, the book displays both the uses of the analytical tradition for theological questions but it also reveals real limitations. The questions of the relation, distinction and unity of Christ and church that lie at the heart of historical ecclesiological investigations (as well as the questions of baptism, Eucharist, liturgical action and liturgical protest – the topics of the final four chapters) are in the end illustrated and even illumined by the tools of analysis Cockayne brings but remain rigidly intransigent to them. This is in no small part due to the fact that the ‘metaphysical extension’ of the incarnation in the church which Cockayne defends is not so much defined as presumed before the tools of analysis are brought to illustrate how such extension might be conceived. The analysis will be more compelling to those who accept such a presumption than to those who do not and who find the language of (social and/or metaphysical) extension unhelpful or improper.

One reason the language of incarnational extension is so often rejected is provided by Cockayne himself when he notes that social extension ‘does not entail that Christ is responsible for everything that is done in the Church or on behalf of the Church’ (p. 72) – a qualification mirrored in the admission that, while (infant) baptism is the concrete inclusion of an individual in this incarnational extension that is the church, it is nevertheless the case that not every infant so included will grow to ‘find personal faith’ (p. 104). Yet if both of these are true and necessary qualifications of metaphysical extension, then the language of extension seems to be greatly attenuated and at best of very limited use to speak of the relation of Christ to the church and the individual Christian. Indeed, it is not only limited but inherently misleading. For it makes no sense to say that ‘I’ am not responsible for an action I perform but my body is so responsible, nor does it make sense of the hypostatic union to say that Christ is not responsible for an action but his body is so responsible. Yet this is exactly what is now being said of Christ and his body the church – and thus this is precisely where the language of extension of Christ into the church as his body breaks down and distorts more than illuminates. This problem is only reinforced and exacerbated when the church's many injustices and abuses of its victims are highlighted in the final chapter.

Regardless, this book takes up the questions it addresses with insight and rigour, and it displays a wealth of learning. Its final chapter on trauma, protest and the relation of corporate and individual culpability with regards to the sins of the church is especially pertinent and incisive. This work will be of special interest for those who look to the methods of analysis as of particular promise for constructive theological work.

(Note and correction: An appeal is made to 1 Cor 2:5–8 to display Paul's restorative social ethic on p. 165 fn. 11; it is in truth 2 Cor 2:5–8 that should be referenced.)