Chalcedonian Definition

The Chalcedonian Definition (also called the Chalcedonian Creed) was adopted at the Council of Chalcedon in A.D. 451. Chalcedon was an early centre of Christianity located in Asia Minor (modern Turkey). The Council was the fourth of the Ecumenical Councils that are accepted by Chalcedonian churches which include the Eastern Orthodox, Catholic, and most Protestant churches. It was the first Council not to be recognised by any Oriental Orthodox church; these churches may be classified as non-Chalcedonian.

The Definition defines that Christ is 'acknowledged in two natures', which 'come together into one person and one hypostasis'. The formal definition of 'two natures' in Christ was understood by the critics of the council at the time, and is understood by many historians and theologians today, to side with western and Antiochene Christology and to diverge from the teaching of Cyril of Alexandria, who always stressed that Christ is 'one'. However, a modern analysis of the sources of the creed (by A. de Halleux, in Revue Theologique de Louvain 7, 1976) and a reading of the acts, or proceedings, of the council (recently translated into English) show that the bishops considered Cyril the great authority and that even the language of 'two natures' derives from him.

The Chalcedonian Definition was written amid controversy between the western and eastern churches over the meaning of the Incarnation (see Christology), the ecclesiastical influence of the emperor, and the supremacy of the Bishop of Rome. The western churches readily accepted the creed, but some eastern churches did not.

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