This is the third volume of a trilogy on the Christian Community in History written by the distinguished American Jesuit scholar, Roger Haight. The first two volumes focused on the development of various ecclesiologies in the course of history: the first dealt with the first fifteen centuries of the Christian church, the second with the development of ecclesiologies, Catholic and Protestant, from the time of the Reformation onwards. This third volume is the product of the lessons the author has learned in the course of writing the first two. It can, he assures us, be read independently of the first two, which is just as well for this reviewer since I have not read any of Haight's books before, but clearly the work is very much informed by, and builds on, the author's historical researches. The aim of the third volume is to work out what is termed “a transdenominational ecclesiology” which is described as “a set of principles and ecclesiological constants that are to be found in the church across its many historical incarnations.” The method underpinning the author's approach is one of “historical phenomenology” which he describes as “ecclesiology from below”. The phrase “Ecclesial Existence” has been chosen because it describes the actual existential, lived reality experienced within the various institutional forms of the Christian church. As such, it cuts across the various denominations and seeks to convey what it is that the various Christian churches aim to achieve and the bonds that unite them.

Despite the fact that the book is clearly written and organised, the argument it presents is novel, dense and highly nuanced, and I found that I had to read it slowly and with great care. Haight is keen to utilise a structure of inquiry independent of any one church's claims or arrangements and this takes him to the sociology of organizations, in order to find a neutral set of terms and ideas that will enable him to find and describe what it is, in organizational terms, that Christian churches have in common. It is perhaps initially surprising to find in a Catholic author extremely few references to other Catholic theologians or scholars. Haight's main theological sources consist of various reports produced by the World Council of Churches. The reasons for this are not difficult to grasp for these reports attempt to stay close to the New Testament and were written by teams of scholars with the intention of being as inclusive as possible, doing justice to the characteristics of the many churches making up the WCC. At the same time, it is not too hard to detect in Haight's approach the influence of his twentieth century Jesuit training and, in particular, of the great Canadian Jesuit scholar, Bernard Lonergan. Phrases like “insight into the data”, “heuristic structure”, “historical consciousness” and “group bias” attest to this influence, as does Haight's sophisticated attention to issues of methodology. Lonergan's name appears nowhere in the book but his influence is evident in just about every page. While Haight names more authors and sources from the Reformed than from the Catholic tradition, there can be no doubting the fact that this is a work emanating from within the contemporary North American Catholic theological tradition.

The two key conceptual tools Haight uses in conducting his argument towards a transdenominational eccelesiology and its corollary, “partial communion” between the churches, are historical consciousness and pluralism. The second, which is born of the first, refers to diversity and difference within a larger unity, in which the differences are not merely tolerated but are recognized as having positive value. He maintains that in the modern church the alternative to relativism is not uniformity but pluralism: unity amid difference. This is the lesson of history: pluralism existed in the church in New Testament times; from the outset the Christian community was tolerant of a diversity of institutional forms, and the various contemporary churches all seek to find scriptural support for their particular form of organization. He concludes: “critical analysis of the church's organizational development argues against the idea that there is one exclusive God-given institutional form for the church.” (p. 77)

Armed with these concepts and insights, Haight's approach is, in the first place, to set up antithetical conceptions of church, such as church as “community” versus church as “hierarchy”. Next, he brings out the nature of the contrast between them, depicting the former as emerging by development out of the group of disciples in dialogue with the environment, and the second as being claimed by its adherents to be the church structure determined during the ministry of Jesus or in a linear development reflecting the will of God, a divinely established institution. Finally, the claim is made that an “existential-historical” approach can appreciate the consistency, integrity and validity of both sets of ideas (p. 113). When comparing claims and counter-claims regarding such things as liturgical practices, forms of ministry, or forms of church governance, Haight argues each time in a similar fashion, attempting to find a larger existential-historical framework that can provide the unity within which differences in practice and understanding can be tolerated and valued; or, as in the case of eucharistic practice, he goes back to the skeletal scriptural account ante-dating the fuller development of such practices in the course of history, and argues that this skeletal form was/is capable of being developed in a diversity of ways. It is in this way that he seeks to establish the simple fact of differences within a larger unity of purpose and function.

Haight is conscious of the fact that the glue that today holds together the churches and distinguishes them from other churches, conferring on them their individual identities, lies much more in their social and historical dimensions than in distinctive doctrines and beliefs. He is also aware of the ease with which people today switch between churches (“spiritual activities” cut across denominational boundaries), as well as of the rapid inculturation of the Christian faith in non-Western forms taking place throughout the globe, and here his sociological approach is valuable in throwing light on what is going on. At the same time, he is very much a theologian and he places theological considerations at the centre of his argument, maintaining that the church was founded by God and its mission is to continue the ministry of Jesus in the world; and that ministry relates to four functions – word, sacrament, healing, and jurisdiction – that enable us to recognise each other as Christian churches. Function is esteemed above form. For example, in the case of ordained ministry, we should pay less attention to a few specific characteristics, such as whether the minister is ontologically set apart or just another lay person, celibate or able to marry, and so forth, and pay more attention to function. On eucharistic practice, he claims that historical consciousness and pluralism have taught us that no one church's language “controls” the mystery of Christ's presence, and the common acceptance that God in Jesus Christ takes the initiative in the eucharist should render the churches more compliant to Christ's commandment of unity in love. Leaders of the churches, who are less willing to engage in interdenominational activities than the people in the pews, “cannot hide behind caution”, he chides. “Christ's call to unity, to communion in his name, is not conditional upon theology; theology is conditioned by it” (p. 216).

It is easy to see why Roger Haight is regarded with such suspicion by Rome – he has recently been forbidden even to publish theology – given the mindset that prevails there and the current equation of pluralism with relativism. However, even at a pragmatic level the Catholic Church has much to gain from the “mutual recognition” and “partial communion” that Haight argues for (there is a devastating footnote on p. 152 about the papacy historically gaining more and more authority over fewer and fewer constituents). In realistic terms it is hard to see how unity in theological understanding can be achieved in advance of the kind of communion Haight advocates. If the Catholic Church wishes to assist the ecumenical process it claims to support, it will need to prescind from the exclusivism and exceptionalism that characterise it at present. This will require a change in the church's culture and, if such a change is ever to take place, it will be in no small part due to the pioneering labours of theologians like Roger Haight.