Vgenopolous examines whether a primacy not simply of honour but of jurisdiction over the whole Church can be established both historically and theologically. It is an issue that fundamentally divides Western (and Eastern) Catholicism from the Eastern Orthodox communion.

A change in the rites of ordination between the First and Second Vatican Councils has made dialogue possible. The Tridentine rites of ordination had focused on the priesthood in which the porrectio of the full chalice and paten with prayers proclaimed the sacrificial character of the priestly office and subsequent episcopal ordination was not to a separate order but simply the giving of episcopal jurisdiction. The rites of Vatican II dispensed with the focus on the episcopal porrectio by having lay members of the congregation present the instrumenta after the laying-on of hands combined with the ordination prayer. Since the imposition of hands for the episcopate has a different form of words, then the episcopate, Vgenopoulos argues, following McPartlan, emerges as a distinct order, and this is what becomes the basis for dialogue on primacy and episcopacy with Eastern Orthodoxy (pp. 77–80). He is only partly correct: the priesthood in both rites is shared with the episcopate which represents its fullness. That Mosaic feature of the Ps.-Hippolytan Traditio apostolica of the mid-third century runs through both Trent and Vatican II.

Vgenopoulos nevertheless must emphasise the episcopate as a distinct order so that his eirenic and mainly Zizoulian thesis can proceed. Vatican II had re-emphasised the Cyprianic concept of the bishop in his diocese: the unity of the Church resided (partly at least) in the episcopal collegium in which bishops accepted each other into the communion of the Catholic Church thus forming the uinculum unitatis (pp. 6–9, 49). Cyprian's embryonic appeal to a Roman centre of the episcopal network, denied by Meyendorff (every bishop is Peter in his local church) was correctly affirmed by Afanassieff: Cyprian had some idea of primacy: ‘a single body must be crowned by a single head’ (p. 60). Thus one Eastern Orthodox view, expressed by Karmiris, that of unity being expressed as a confederation of autocephalous Churches, is questionable: it can be regarded as a highly Protestant notion since the Orthodox Church has always acknowledged primacy in the sense of the Thirty-Fourth Apostolic Canon's demand for metropolitans (pp. 54–7, 62–4).

Vgenopoulos follows Zizioulas's development of the concept of eucharistic ecclesiology in his quest for a sacramental view of primacy that is jurisdictional, iure diuino. Such a view of unity and ecclesial order is firmly rooted in the tradition of Ignatius of Antioch (but not in the Didascalia apostolorum, as Vgenopoulos and Zizioulas assert, p. 87). The bishop is the focus of unity as representing mystically and sacramentally the Father God presiding over the apostolic council of presbyters and attended by the diaconal ministry of Christ the servant in a corporate union into which the laity are draw into incorruptibility (cf p. 87). In this ecclesiology, the unity of the local Church is the mystery of the one in the many, ‘of one body in Christ’, in which the one bishop mystically represents in his person (or eucharistic persona) ‘your whole multitude in faith and love’ (Ignatius, Ephesians 5.1; Magnesians 2; Trallians 1.1). This we may express rightly, in Zizioulas's language, as ‘corporate personality’ in the sense in which this term is used by Old Testament scholars (pp. 7, 13). But if there is but one eucharist celebrated by different communities not simply throughout provinces but throughout the world, then the mystery of the one in the many will be expressed in a bishop who is the universal primate and on the same argument (p. 154).

Vgenopoulos argues Zizioulas's theological case cogently, but there is a suppressed historical dimension to it. Congar's principle is quoted with approval: that ‘apostolic succession is a succession of apostolic communities via their heads, i.e. the bishops' (p. 87). But Zizioulas, whilst following a very persuasive theological argument, is guilty of poor historical judgement in tracing the development of that principle in the first centuries of church history. He asserts (in Eucharist, bishop, Church: the unity of the Church in the divine eucharist and the bishop during the first three centuries, Brookline, Ma 2001, 126) that apostolic succession must be in terms of one community in one geographical territory: two or more communities under their respective bishops could not co-exist within the one Catholic Church.

Yet Christian communities can have distinct cultural forms with their distinct historical patrimonies, and yet be within the same apostolic succession: they may even claim that distinction on the grounds of their descent from different Apostles. In this form the argument for universal primacy denies enculturalisation theses and becomes extremely backward. But it is highly convenient for Eastern Orthodoxy if it wishes to persist in its attacks upon what it stigmatises as ‘uniatism’ in those communities that have maintained, culturally, many features of their eastern rites yet remained in or re-established full communion with the Holy See. The assertion that territory is an integral part of the dogmatic concept of the apostolic tradition has lead Zizioulas (and Vgenopoulos) into the appalling historical judgement that Cyprian's theology of catholic unity was completely uninfluenced by Roman jurisprudence and political theory. It also now has unfortunate geopolitical consequences in the threat to Eastern Catholics in the Ukraine from the ambitions of Putin and his spiritual advisors.