Coucil of Chalcedon 451 AD

Proceedings & Doctrines

Key Terms to Know

Here are some common words that one may see when looking through doctrinal statements on Christianity, or when involving oneself in modern theological debates.

The branch of theology that studies the nature, person, and work of Jesus Christ – which is the main topic discussed at the Council of Chalcedon.

A heresy (teaching that goes against the established doctrines) that claimed Christ’s divine nature completely absorbed His human nature, leaving Him with only one divine nature. This is what the Chalcedonian churches were trying to avoid by instating the doctrine of Dyophysitism.

The belief that Christ has one united nature, which is both fully divine and fully human, without separation or division. This is the belief of the Oriental Orthodox Churches in the modern day, as they rejected the Council of Chalcedon. Based on the teachings of St. Cyril of Alexandria.

The theological concept that Christ’s two natures (divine and human) are united in one person, or hypostasis. The council affirmed this union to combat heresies like Nestorianism and Eutychianism.

This is the belief that Christ exists in two distinct natures, one fully divine and one fully human, united in one person. This is the position that the Council of Chalcedon came to affirm. Though it may seem very similar to the definition of Miaphysitism, it has been the source of debate and divide between the churches since the council.

The belief that Christ has only one nature, either purely divine or a fusion of divine and human, as opposed to two distinct natures. This was incorrectly applied (and still misapplied) to the Oriental Orthodox Churches during/after the Council of Chalcedon. The belief they hold is Miaphysitism, not monophysitism.

The Chalcedonian Debate

The Council of Chalcedon wanted to address theological questions about Christ’s nature, but unfortunately its decisions left the Christian world divided. For the Oriental Orthodox Church, the council’s conclusions were a betrayal of the faith that had been passed down from earlier church fathers, such as St. Cyril of Alexandria. For the rest who affirmed the council (these churches who would later split again to become the Eastern Orthodox Church and the Roman Catholic Church), these were important doctrines intended to weed out heretics. To this day, one must understand this council if they are to understand the division of the churches in modernity.

How Did The Council Begin?

The Beginning

In 451 AD, Emperor Marcian officially calls for the Council of Chalcedon with intentions to unify the Roman Empire under a single Christian doctrine despite looming theological disputes. Bishops from all over the empire, including key figures from Rome, Alexandria, Antioch and Constantinople, were invited to participate. Around 520 Bishops showed up to attend this meeting.

Dioscorus of Alexandria

Only adding to the controversy, Dioscorus of Alexandria, who presided over the Second Council of Ephesus (449 AD), was not even allowed to participate in the council after being accused of being a heretic. This exclusion alienated a large part of the Church and set a rather odd tone for the proceedings, with many of the members seeing it as a move to lessen the Alexandrian influence.

Timeline of The Council

Dyophysitism vs. Miaphysitism: Two Perspectives on Christ’s Nature

At the center of the Council of Chalcedon’s focus was was the debate on how to articulate the relationship between Christ’s divinity and humanity. The Chalcedonian Definition declared that Christ exists “in two natures, without confusion, without change, without division, without separation,” a position now referred to as dyophysitism. This doctrine states that Christ’s divine and human natures remained distinct but united in one person. For the Chalcedonian supporters, this language was necessary to counter heresies like Nestorianism, which divided Christ into two persons, and Eutychianism, which denied His humanity​ (Chalcedon and the Need For Unity)

However, the Alexandrian tradition, which was represented by Dioscorus of Alexandria and is upheld today by the Oriental Orthodox Church, rejects the phrase “in two natures” in favor of miaphysitism. This is rooted in the teachings of St. Cyril of Alexandria, and miaphysitism states that Christ’s divinity and humanity are united in “one incarnate nature of God the Word.” This doctrine is able to depict the indivisible aspect of Christ’s divine and human natures after the union, which preserved the mystery of the Incarnation without risking confusion​.

Despite the disagreements, both sides wanted to preserve the mystery of Christ’s humanity. Dyophysitism aimed to make sure that His two natures were not confused or merged. On the other hand, Miaphysitism strived to show the unity of Christ’s humanity, and wanted to avoid any language that could imply separation of his two natures. The debate seems to approach the same mystery with different theological stances. Subsequent dialogues between Chalcedonian and Oriental Orthodox Churches have revealed that much of the division was rooted in language barriers and cultural misunderstandings rather than overt doctrinal differences. Efforts to reconcile these differences still continue to this day​.

Overview of Chalcedon

Click below to watch an informative video covering an overview of the sessions of the council.

The Final Outcome

In The End, The Council Decides On Dyophysitism

The Council of Chalcedon ultimately affirmed the Chalcedonian Definition, which states that Christ is fully divine and fully human, existing in two distinct natures united in one person. They felt it was correct because it addressed heresies like Nestorianism and Eutychianism,which had affected Christian doctrine across much of the Roman Empire.

Despite its intentions, the council ended up widening the gap between believers in Christ. Many Christians in Egypt, Syria, and Armenia rejected its decisions, which lead to a schism with the Oriental Orthodox Church that persists to this day.
How This Affects The Church Today