Abstract
The paper discusses the problem of Orthodox‐Catholic disunity by naming non‐theological and discussing theological issues behind the issues in bilateral dialogues between the Churches. The main theological issue is the absence of agreement on which doctrinal differences should or should not count as church‐dividing. The author argues that the concept of the ‘hierarchy of truths’, introduced by Vatican II's Unitatis Redintegratio is a promising heuristic tool for distinguishing the doctrines that pertain to the ‘fundamental Christian faith’ and other important doctrines that do not have the same authoritative status. The author proposes that the agreement on the ‘Nicene faith’ could function as a sufficient condition for the Eucharistic communion between the two Churches on two grounds of the use of the Creed in the rites of initiation and the liturgy. The author subsequently articulates three potential objections to his proposal, responds to these objections, and finishes the paper with what could be called a ‘Nicene Formula of Reunion’. The proposed Formula includes a commitment to seeking an increasingly greater convergence on doctrinal and ecclesiastical issues on which there is continuing, although not church‐dividing disagreement.