Council · 451 · 8 October

Council of Chalcedon

Christians agreed that Jesus is God and human, but disagreed about how to say both without weakening either truth. Some explanations seemed to split Jesus in two; others seemed to make his humanity disappear into his divinity. Chalcedon gave the formula that became central for Catholic, Orthodox, and most Protestant Christians: Jesus Christ is one person, fully God and fully human. It did not solve every disagreement, but it set a lasting boundary for how Christians speak about Jesus.

At a glance

Type: Council
Date remembered: 8 October, AD 451
What kind of event is this?: A council or settlement that changed the church's public teaching, discipline, or historical direction.
Key line: One person in two natures, without confusion or division.

Highlights

Leo's letter was received.
Eutyches' teaching was rejected.
The council defined Jesus as fully God and fully human.
Some Eastern churches did not accept the definition.

How it happened

What happened

Bishops met at Chalcedon after the Eutychian controversy and the disputed Second Council of Ephesus.

The argument

Could Christ's humanity and divinity be confessed without either dividing him or blending his natures?

What changed

The council defined Christ as one person in two natures, divine and human.

Why it matters

Chalcedon became the main guardrail for saying that Jesus is fully God, fully human, and one Lord.

Aftermath

Many Egyptian, Syrian, Armenian, and Ethiopian Christians rejected Chalcedon, creating divisions that still remain.

People in the story

Pope Leo Ic. 400 – 461Bishop of Rome 440-461. His Tome (Epistula 28) was acclaimed at the Council of Chalcedon (451). Negotiated with Attila in 452.

Eutychesc. 380 – c. 456Archimandrite at Constantinople whose monophysite teaching ('one nature after the union') was condemned at the Home Synod (448) and at Chalcedon (451). Heretic.