Commemoration and Dissent: Canon 15 of the First and Second Council (861) in Byzantine History

Eucharistic communion stands as the cornerstone of ecclesial unity in the Byzantine Church, yet the boundaries of this unity have been subject to debate, particularly concerning the commemoration of bishops within the liturgical context. This paper examines the limits of communion in the Byzantine Church, focusing on the complex and often controversial applications of Canon 15 of the First and Second Council in Constantinople (861). This canon outlines specific conditions under which the commemoration of a bishop, and consequently communion with him, could be ceased. Canon 15 provides a mechanism for separation from hierarchical superiors when they openly preach heresy. This principle challenges the traditional understanding of hierarchical authority and demands a nuanced interpretation of doctrinal purity and ecclesial order. The canon posits that when a bishop publicly proclaims a heresy condemned by the holy councils or Fathers, clergy and laity are not only permitted but also encouraged to cease commemorating him. This action is framed not as schism but as a defense of Orthodoxy and a preservation of the Church’s true unity. This paper will explore the historical reception and practical implementation of Canon 15 across several centuries of Byzantine history. Cases such as the Tetragamy controversy during the reign of Emperor Leo VI, and instances of ecclesiastical division in the thirteenth century (Council of Lyon), fourteenth century (Palamite debates) and finally Council of Ferrar and Florence will be investigated. These case studies reveal the complexities and challenges of applying Canon 15, demonstrating the fine line between justified separation and schismatic activity. The paper will also consider how Byzantine commentators and legal scholars understood and interpreted Canon 15. By analyzing the historical context and application of Canon 15, this paper aims to shed light on the nuanced understanding of communion, authority, and dissent in the Byzantine Church.