Golden Age

On the Unity of Christ & Third Letter to Nestorius

Cyril of Alexandria · c. 428 – 444

Historical Context

Patriarch of Alexandria and the driving theological voice at the Council of Ephesus (431), which condemned Nestorius.

Summary

Cyril defends the single subject of Christ — one incarnate person of the Word — and the title Theotokos for Mary. On the Unity of Christ is a lucid dialogue setting out his mature Christology; his letters to Nestorius were incorporated into the definitions of Ephesus and, in modified form, Chalcedon.

Major Themes

  • Theotokos
  • Hypostatic union
  • One incarnate nature of the Word
  • Christ as single subject

Important Quotations

If anyone does not confess that Emmanuel is God in truth, and therefore that the holy Virgin is the Mother of God… let him be anathema.
Third Letter to Nestorius, Anathema 1

Related Timeline Events

Related Doctrines

Primary Sources

Further Reading

  • John A. McGuckin, Saint Cyril of Alexandria and the Christological Controversy