Section 05: The Formula of Reunion (433)
Two years after the Council of Ephesus, Alexandria and Antioch were still in schism. Under imperial pressure and through patient mediation, the two sees were reconciled in 433 on the basis of a dyophysite Antiochene creed — the Formula of Reunion — which Cyril accepted in his letter Laetentur caeli. This section examines the reconciliation and its text, and then the price it exacted: the alienation of the zealots on both wings, whose protests seeded the later Miaphysite and East-Syrian schisms. The Formula is the strongest evidence that Cyril’s core commitment was the one hypostatic subject rather than the mia physis slogan — and a peace held together, in the end, largely by Cyril himself.
Tradition: Pan-Orthodox (Church Father)
Contents
| File | Description |
|---|---|
| reconciliation-with-antioch.md | The post-Ephesus schism and imperial pressure; the mediation of Acacius of Beroea and Paul of Emesa (the Alexandria Theotokos sermon); the Symbol of Union and Theodoret’s probable draft; the Formula of Reunion quoted and analyzed (union of two natures, double consubstantiality, Theotokos, the one prosōpon); Cyril’s acceptance in Laetentur caeli (Ep. 39, 433); why this shows his real commitment was the one hypostatic subject; the bridge to Chalcedon’s later use of the language. |
| the-cost-of-peace.md | Both flanks alienated: the strict Cyrillian hardliners who thought Cyril sold out, and his defenses (Letters to Acacius of Melitene, Eulogius, and Succensus; the theoria/contemplation distinction); the intransigent Antiochenes who broke with John of Antioch over the abandonment of Nestorius (the “Nestorianizing” remnant → the Church of the East); how the Formula sowed the seeds of both the Miaphysite and East-Syrian divisions; Cyril’s own mia physis hardening after 433; the lasting ambiguity of a peace held together by one man. |
How to Use
- For study: Read reconciliation-with-antioch.md first for the settlement itself — how the schism was healed and what the Formula actually says — then the-cost-of-peace.md for the price of that peace on both flanks and the schisms it foreshadowed.
- For reference: Each file is self-contained, with a summary, inline citations to Cyril’s letters (by Ep. number, PG column where secure, and translation), and a references section. Load either independently.
- For fairness: This section flags genuinely disputed points — the precise date of the reunion, the authorship of the Symbol of Union, and the character of Cyril’s later mia physis emphasis — as
[Disputed: ...]rather than smoothing them over, and states the grievances of both alienated wings in their own terms.
Cross-References
- Section 04 — The Aftermath: the unstable post-Ephesus settlement that the reunion repaired.
- Section 04 — The Contested Council: Ephesus 431, where the parties first divided.
- Section 03 — The Twelve Anathemas: the documents the strict Cyrillians feared Cyril had abandoned and that the Formula had to negotiate around.
- Section 06 — Mia Physis and the Hypostatic Union: the systematic Christology the Formula and the theoria distinction illuminate.
- Section 06 — Chalcedon and the Non-Chalcedonians: how the Formula’s language reappeared at Chalcedon and how the cost-of-peace fractures became permanent.
- St. Maximus the Confessor: the later defense of the dyothelite-Chalcedonian reading of this Christological tradition.
- Ecumenical Councils: the broader conciliar framework.
References
Primary source is Cyril’s Letter to John of Antioch (Laetentur caeli), Ep. 39, PG 77, 173–181; CPG 5339, which quotes the Formula of Reunion in full; with his defensive letters to Acacius of Melitene (Ep. 40), Eulogius (Ep. 44), and Succensus (Epp. 45–46). The Formula is also preserved in the conciliar Acts (ACO I.1). Standard translations: John A. McGuckin, St. Cyril of Alexandria: The Christological Controversy (SVS Press, 2004); FC 76 (McEnerney). Scholarship: McGuckin; Norman Russell, Cyril of Alexandria (Routledge, 2000); Susan Wessel, Cyril of Alexandria and the Nestorian Controversy (OUP, 2004). Full citations appear in each content file.