The Concept of "Sister Churches" in Catholic-Orthodox Relations Since Vatican II

Reddit icon
e-mail icon
Twitter icon
Facebook icon
Google icon
LinkedIn icon
Will Cohen
  • Eugene, OR: 
    Wipf & Stock Publishers
    , September
     326 pages.
     For other formats: Link to Publisher's Website.


The Concept of “Sister Churches” in Catholic-Orthodox Relations Since Vatican II is the culmination of the dissertation that Will Cohen defended at Catholic University and first published in Studia Oecumenica Friburgensia (Aschendorff Verlag, 2016). It is a valuable work offering rich commentary regarding the advances and setbacks in Catholic-Orthodox ecumenical relations. Tracing the rise and fall of the expression “sister churches,” Cohen argues that Ecumenical Patriarch Athenagoras first invoked the term in a letter to Cardinal Bea of the Vatican Secretariat for the Promotion of Christian Unity in 1962. By 1969, it enjoyed standard usage by Catholic and Orthodox dialogue participants, and likewise by Popes Paul VI and John Paul II. However, since the turn of the century, it is nowhere to be found in the vocabulary of bilateral dialogues. In addition to documenting the compelling lineage of the term, the aim of Cohen’s project is to argue for the rehabilitation of the language of “sister churches.” 

The first chapter of Cohen’s work examines the language of sister churches across scriptural, patristic, and medieval sources. The second chapter considers the modern emergence of the term in the period between 1958 and 1972. That time frame begins with the election of Pope John XXIII who convened the Second Vatical Council and ends with the death of Patriarch Athenagoras and the publication of the first edition of the Tomos Agapis, a collection of the various materials and sources emanating from the correspondence between Rome and Constantinople. The third chapter studies patterns and ambiguities of the term “sister churches” during two important periods: from 1958 to 1972 and 1972 to 2000. Cohen also discusses a number of different ways to understand the identities of the “sister churches,” ranging from a definition that focuses on those churches that belong to a single, undivided communion, and four others that involve various trans-confessional pairings. 

A demarcation line was drawn when the Vatican Congregation for the Doctrine of the Faith (CDF) issued its Note on the Expression “Sister Churches” on June 30, 2000Reflecting the then growing retrenchment in official perspectives on Catholic ecclesiology, the Note sought to circumscribe the application of the expression “sister churches.” Chapters 4 and 5 survey Catholic and Orthodox theologians, exploring the perspectives of both advocates and critics of “sister churches.” In regards to the Catholic critique, special attention is given to the work of Adriano Garuti, documents from the CDF, and Hervé Lagrand. Cohen shows how the concept of “sister churches” became intertwined with an interpretation of the phrase “subsists in” in article 8 of Vatican II’s Constitution on the Church, Lumen gentium, and with the issue of relationship and priority between local or particular churches and the universal church. 

An emphasis on Roman Primacy inextricably permeated all of the above. As Cohen explains, “Garuti argued that one must utterly reject any idea ‘that two Churches exist, the Catholic Church and the Orthodox Church, which constitute two parts of the one Church that existed in the first millennium…’ since this would mean, according to Garuti, that the ‘Church of Christ no longer exists as one in history, but is in fieri [in the state of becoming] through the convergence or reunification of the two sister Churches’” (141). The Note that was issued by the CDF in 2000 followed this line of reasoning. It declared that the universal church is “not sister but mother of all the particular churches,” and further asserted that the “patriarchal structure typical of the East never developed in the West” (153). In 2006, the title “Patriarch of the West” was erased from the list of titles given to the pope in previous editions of the Annuario Pontificio, the Vatican’s official yearbook. Cohen documents Cardinal Walter Kasper’s criticism that the CDF Note “must be understood as a dismissal of [communion] ecclesiology and an attempt to restore Roman centralism.” (155) 

In his conclusions to chapter 4, Cohen observes that Garuti considers the Orthodox Churches to be “churches in an imperfect and analogous manner with respect to the Church, from which they derive their existence and salvific efficacy.” However, although Garuti fails to clarify whether “Church” refers to the Church of Christ which subsists in the Catholic Church or to the Catholic Church in which the Church of Christ subsists, Cohen acknowledges that he “does justice to the Catholic position that the continuity and unity and the visible presence in history of the one Church of Christ, in which all the means of grace are available, cannot be said to depend on reunification with the Orthodox Churches” (181).

Cohen ends chapter 5 by proposing the idea of ecclesia extra ecclesiam (church outside the church) as a possible ecclesiological solution to the problem of “sister churches.” In chapter 6, Cohen reprises Yves Congar’s view of schism as a “gradual estrangement” which never became total. He notes that Orthodox critics of the language of “sister churches” see Roman primacy as incompatible with the synodality of the Orthodox churches, while Catholic critics consider the expression a threat to Roman primacy. Cohen argues that there is an asymmetrical understanding of how the Church of Christ is present in these two positions; however, he suggests that there is also an interdependence that can and should be acknowledged. Cohen proposes holding these qualities of asymmetry and interdependence in tension, because despite their differences and separation, neither church can do without the other. He concludes that “there can be no question of playing it safe” in recognizing or not recognizing the sacramental and ecclesial reality of a separated community, nor in calling or not calling the other a “sister church.” Baptizing those who were already baptized, or bringing persons into the Church of Christ who were already in it, Cohen argues, is to divide Christ into “my Christ” and “your Christ” (284).

Altogether, Cohen’s The Concept of “Sister Churches” is sure to spark insightful reflection, and I wholeheartedly recommend it as a resource for ecclesiological and ecumenical studies.

About the Reviewer(s): 

Bernard P. Prusak is Professor in the Department of Theology and Religious Studies at Villanova University.

Date of Review: 
July 18, 2018
About the Author(s)/Editor(s)/Translator(s): 

Will Cohen, a subdeacon in the Orthodox Church in America, is associate professor of theology at the University of Scranton in Pennsylvania, and serves as President of the Orthodox Theological Society in America. 


Reading Religion welcomes comments from AAR members, and you may leave a comment below by logging in with your AAR Member ID and password. Please read our policy on commenting.