About this work
That Christ Is One is one of St Cyril of Alexandria’s clearest explanations of the Church’s confession that Jesus Christ is one Lord and Son. In dialogue form, Cyril insists that the eternal Word truly became man without ceasing to be God and that His humanity is neither a separate human subject nor dissolved into the divinity. This unity shapes the whole saving mystery: the one born of the Virgin Mary, who suffers and rises in the flesh, is the same divine Son, and His own flesh is life-giving because it belongs to the Word Himself.
Historical context
Modern scholarship generally places the dialogue in Cyril’s mature post-Ephesus period, around 438 or later, several years after the Council of Ephesus in 431. The council had condemned Nestorius, but debate continued over how Christians should speak of the distinction and unity of Christ’s divinity and humanity. Cyril argues against accounts that, in his judgment, left the Word and the man Jesus joined only by an external conjunction, while he also rejects confusion or change in the Incarnation. The work belongs to the final phase of his Christological controversy and presents his teaching in a settled, explanatory form.
Contents
The dialogue proceeds by question and answer through the biblical language Christians use about Christ. Cyril begins with the Son’s true divinity and the Word’s becoming flesh, then explains the title Christ, the self-emptying of Philippians 2, and the difference between true union and a merely external conjunction. He answers objections drawn from Christ’s growth, obedience, prayer, fear, suffering, and death, insisting that these genuinely human experiences belong to the one Son in His flesh. The closing argument turns to resurrection, salvation, and Christ’s life-giving flesh and blood, which Cyril insists are the Word’s own and not those of another human subject.
Text & source details
Editions
- Edition
- Pusey Greek (1877)
- Reader label
- Ancient Greek
- Publication
- P. E. Pusey, Sancti Patris Nostri Cyrilli Archiepiscopi Alexandrini, Oxford, 1877, vol. VII, pp. 334–424
- Date
- 1877
- Rights
- Public-domain edition; Internet Archive item marked with the Public Domain Mark.
- Edition
- Voices of the Fathers Modern English
- Reader label
- Modern English — VOTF
- Translator
- Voices of the Fathers editorial project
- Publication
- Voices of the Fathers
- Date
- 2026
- Rights
- Voices of the Fathers Modern English is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0), to the extent copyright and related rights subsist in the translation and associated editorial material. Commercial reuse requires separate permission from Voices of the Fathers. The underlying ancient text and identified public-domain source editions retain their respective status.
- Edition
- P. E. Pusey (1881)
- Reader label
- English — Pusey (1881)
- Translator
- Philip Edward Pusey
- Publication
- Library of the Fathers 47, Oxford, 1881, pp. 237–319
- Date
- 1881
- Rights
- Public-domain historical edition where applicable.
Text and edition sources
P. E. Pusey, ed., Sancti Patris Nostri Cyrilli Archiepiscopi Alexandrini: De recta fide… Quod unus Christus dialogus, Oxford, 1877.
Applies to: Ancient Greek Internet Archive metadata supplies the Public Domain Mark. Source websiteThat Christ Is One, Voices of the Fathers Modern English, Voices of the Fathers, 2026, CC BY-NC 4.0.
Applies to: Modern English — VOTF Source websiteP. E. Pusey, trans., That Christ Is One, in S. Cyril of Alexandria, Library of the Fathers 47, Oxford, 1881, pp. 237–319.
Applies to: English — Pusey (1881) Public-domain historical print edition; online transcription used as an extraction witness. Source websiteOverview research
Cyril of Alexandria, On the Unity of Christ, trans. John Anthony McGuckin, Popular Patristics Series 13 (Crestwood, NY: St Vladimir’s Seminary Press, 1995).
Source websiteJonathan Morgan, “The unity of Christ in Cyril of Alexandria’s Festal Letters,” Scottish Journal of Theology 77, no. 2 (2024): 163–174. doi:10.1017/S0036930623000698.
Source website
