Miaphysitism (one incarnate nature of Christ)

The christological controversies of the fifth century were arguments about how to say something all parties agreed on: that Jesus Christ is fully God and fully human, one subject and not two.

Nestorius was condemned at Ephesus in 431 for a way of speaking that appeared to make Christ two persons in loose association. Cyril of Alexandria, who led that condemnation, used a formula he believed came from Athanasius: one incarnate nature of God the Word. Eutyches was then condemned in 448 for taking the formula to mean that Christ's humanity was absorbed into his divinity like a drop of honey in the sea, so that he was no longer consubstantial with us. That position is properly called monophysitism, and every party in the dispute rejected it.

The Council of Chalcedon in 451 defined Christ as one person in two natures, divine and human, without confusion, change, division or separation. The definition was framed with Eutyches in view, but it used the word nature in a sense that Cyril's followers could not accept, since for them one nature was the guarantee of a single subject. The churches of Egypt, Syria and Armenia refused to receive the council, holding that its language divided Christ and departed from Cyril, and that the imperial enforcement that followed was coercion.

Miaphysitism, the resulting position, holds that divinity and humanity are united in one incarnate nature, without mixture, confusion, alteration or separation. The humanity is complete and remains what it is; the union is real and permanent; there is one subject. Oriental Orthodox theologians point out that they use the same four adverbs Chalcedon does, and they reject the label monophysite as a description of Eutyches' error rather than of their own faith.

The churches that rejected Chalcedon are the Coptic Orthodox church of Egypt, the Syriac Orthodox church, the Armenian Apostolic church, the Ethiopian and Eritrean Orthodox churches, and the Malankara church of India. Collectively they are the Oriental Orthodox communion, distinct from the Eastern Orthodox churches that accepted the council, and numbering somewhere above sixty million people.

The separation had causes beyond theology. Chalcedon's reception was entangled with the rivalry of Alexandria, Antioch and the new imperial see of Constantinople, and with the resentment of Egyptian and Syrian populations toward Greek administration; imperial attempts to force compliance and the later compromise formulas of monoenergism and monothelitism, condemned in their turn, deepened the rupture rather than closing it. When the Arab conquests removed these provinces from Byzantine control in the seventh century, the division became permanent as a matter of geography as well as doctrine.

Modern dialogue has substantially dissolved the theological charge. Unofficial consultations from 1964 and formal agreed statements between Oriental Orthodox and Eastern Orthodox in 1989 and 1990, and between the Coptic and Roman churches in 1973 and between Rome and the Syriac church in 1984, concluded that the two christologies are equivalent and that the ancient anathemas were directed at positions neither side actually held. The two families now recognise each other's faith as orthodox.

They remain separate churches, because the outstanding questions are the lifting of anathemas against revered figures on both sides, the status of the councils from Chalcedon onward, and the ordinary difficulty of reuniting jurisdictions after fifteen centuries apart. The case is often cited as the clearest example in Christian history of a schism produced by vocabulary, though historians caution that the vocabulary carried real weight for those who used it.