Chalcedon settles the nature of Christ

The Council of Chalcedon in 451 AD convenes with over five hundred bishops — the largest council in the church's history to this point — and produces the definition that becomes the Christological standard for most of Christianity.

When Leo's Tome is read aloud, the bishops respond with acclaim. Dioscorus, who controlled the Robber Council, is deposed. The Monophysite position is condemned. And the council produces its definitive statement on the nature of Christ.

The Chalcedonian definition does something elegant: it does not try to explain how Christ can be both fully God and fully human. It simply insists on both, and insists that the two are held together in one person — without confusion, without change, without division, without separation. The four negative clauses are the heart of it. They mark out what is not true so that the truth has room.

The definition is not universally accepted. The Coptic church of Egypt, the Ethiopian church, the Armenian church, and the Syrian church all reject Chalcedon and maintain a modified Monophysite position. These are the Oriental Orthodox churches — still existing today, still confessing a slightly different formula.

The wound Chalcedon fails to fully heal will persist for fifteen centuries. Ecumenical dialogue between Chalcedonian and non-Chalcedonian churches in the twentieth century will produce remarkable agreements, and both traditions will wonder whether the fifth-century argument was partly about language and partly about theology, and whether the language that divided them was ever as far apart as it seemed.

Without confusion, without change, without division, without separation. The four negatives of Chalcedon have been called the most important theological formula in Christian history.

They do not explain the mystery. They protect it.

The church has always been tempted to resolve the mystery by emphasizing one side — making Christ so divine that his humanity becomes decorative, or so human that his divinity becomes metaphorical. Chalcedon refuses both resolutions.

The full humanity of Christ matters because it means he has been where you are. The full divinity matters because it means what he accomplished there has infinite weight.

Both. Without confusion. Without separation. One Christ.