Unity is the categorical imperative of the church. It is not just the church's bene esse, but its esse. In addition to being a theological concept, unity has become a raison d'etre of various structures that the church has established and developed. All of these structures are supposed to serve the end of unity. However, from time to time some of them deviate from their initial purpose and contribute to disunity. This happens because the structures of the church are not a part of its nature and can therefore turn against it. They are like scaffolding, which facilitates the construction and maintenance of a building without actually being part of it. Likewise, ecclesial structures help the church function in accordance with its nature but should not be identified with the church proper. This book considers the evolution of some of these church structures and evaluates their correspondence to their initial rationale. It focuses on particular structures that have developed in the eastern part of the Christian oecumene, such as patriarchates, canonical territory, and autocephaly, all of which are explored in the more general frame of hierarchy and primacy. They were selected because they are most neuralgic in the life of the Orthodox churches today and bear in them the greatest potential to divide. ""Cyril Hovorun is emerging as one of the foremost ecclesiologists of modern times. . . . Hovorun's analysis has profound insights for ecumenism, as well as for the struggle for some practical coherence within the Orthodox Churches themselves."" --Andrew Louth, Durham University ""Hovorun's critique of the limitations of hierarchy-centered and eucharistic ecclesiologies is bound to be controversial, while making an important contribution to the ongoing dialogue between the Christian East and West."" --Paul L. Gavrilyuk, University of St. Thomas, Minnesota ""Hovorun offers a refreshing analysis of the various structures of the church as they developed over time. . . . [He] convincingly argues that the nature of the church should not lead to reified structures, and points the way to faithful reform in the face of new problems and challenges facing the church."" --Aristotle Papanikolaou, Fordham University Cyril Hovorun is a senior lecturer at Sankt Ignatios Academy/Stockholm School of Theology in Sweden.