Thanks to Liverpool University Press we can read the full proceedings of the Council of Chalcedon.  The Council opened on 8 October, and its first job was to review what had happened at Ephesus in 449. It did so and it condemned Dioscorus and exiled him. At a stroke, Alexandria’s empire-building had collapsed.

It is important to emphasise that Dioscorus was not found guilty of heresy. He was condemned for his conduct at the 449 Council and, refusing to attend the session where he was required to explain himself at Chalcedon, he was deprived of his See and sent into exile. Quite why he did not appear is not clear, but the consequences were fatal for his tenure of the See of Alexandria. Because of what happened next, the issue of his conduct and his beliefs became intertwined, and helped create a schism which has not healed to this day. Schisms but rarely happen as a one-off event. Chalcedon would become the focal point for the eventual schism, but the main issue would become the outcome of the on-going debate over what was and was not orthodox Christology.

The central part of the Council was the consideration of the Tome of Pope Leo. It is sometimes presented as though it were a synthesis of the Alexandrian and Antiochene views. The Oriental Orthodox, the descendants of those who rejected Chalcedon, tend to make noises about Leo’s Latin not being as flexible as the Greek. Both views give Leo little credit for a formula which has endured to this day.

Leo was the first Pope to be a considerable theologian, and we see a line of thinking in his Tome which reveals that. There is, as one might expect, a decisive rejection of Nestorius by emphasising that the Son is co-eternal with the Father – he is begotten, not made. But Leo went on to deal with a question that even today causes some to err. Jesus, as Paul emphasises, emptied himself to take on our humanity, but that did not mean, Leo argued, that he ceased to be God. Leo adopted Cyril’s language about Jesus having two natures, a human and a Divine nature, and he used Cyril’s formula of two natures in one Person. But those two natures were not intermingled, they did not create some kind of hybrid God-man who was half God and half man. Christ remained fully God and fully God; the two natures retained their distinctiveness in the One Person of Jesus, and they acted ‘in communion’ in him. The Divine nature did those things appropriate to it (such as performing miracles), while the human nature did likewise – suffering as men do, and dying as men do. The fact that there was one Person meant that each nature could be spoken about in terms of the other in a sharing of qualities or an interchange of properties – a communicatio idiomatum (communion of idioms). Thus one could say that the Son of Man came down from heaven and took flesh from the Virgin Mary.

It is worth giving the wording:

We, then, following the holy Fathers, all with one consent, teach men to confess one and the same Son, our Lord Jesus Christ, the same perfect in Godhead and also perfect in manhood; truly God and truly man, of a reasonable soul and body; consubstantial with us according to the manhood; in all things like unto us, without sin; begotten before all ages of the Father according to the Godhead, and in these latter days, for us and for our salvation, born of the virgin Mary, the mother of God, according to the manhood; one and the same Christ, Son, Lord, Only-begotten, to be acknowledged in two natures, inconfusedly, unchangeably, indivisibly, inseparably; the distinction of natures being by no means taken away by the union, but rather the property of each nature being preserved, and concurring in one Person and one Subsistence, not parted or divided into two persons, but one and the same Son, and only begotten, God the Word, the Lord Jesus Christ, as the prophets from the beginning have declared concerning him, and the Lord Jesus Christ himself taught us, and the Creed of the holy Fathers has handed down to us.

The Creed is in line with the Nicene Creed, and affirms the pre-existence of Christ and His equality with Father; it also proclaims His perfect humanity and divinity.

The Tome was pored over and extensively discussed by the Bishops, and that needs to be noted; this was most certainly not a case of a Pope laying down the law and expecting everyone to follow suite. But then, except in anti-Catholic legend, the occasions upon which the Pope lays down the law as opposed to invites discussion, are vanishingly rare. Leo’s Tome set forth the Pope’s views, and when the Bishops finished their discussion it was clear that he agreed with Cyril’s Christology, and they were therefore happy to declare, as the record states that:‘Peter speaks through Leo.‘

Quite what that meant would be tested immediately. At the end of the Council, the Fathers had ratified a new canon, Canon 28, which, on the basis of what had been decided at the Council of Constantinople in 381, conceded to the See of Constantinople the second place in the Christian Church. This created an immediate crisis, and before returning to the more dramatic and long-term results of the Council, we must deal with the controversy caused by Canon 28.