stylistic:style_transfer
Council of Chalcedon (AD 451)

In 451, those who accepted the Council of Chalcedon similarly classified those who rejected it as Monophysite heretics. The Churches that refused to accept the Council considered instead that it was they who were orthodox; they reject the description Monophysite (meaning only-nature) preferring instead Miaphysite (meaning one-nature). The difference in terms may appear subtle, but it is theologically very important. "Monophysite" implies a single divine nature alone with no real human nature—a heretical belief according to Chalcedonian Christianity —whereas "Miaphysite" can be understood to mean one nature as God, existing in the person of Jesus who is both human and divine—an idea more easily reconciled to Chalcedonian doctrine. They are often called, in English, Oriental Orthodox Churches, to distinguish them from the Eastern Orthodox Churches.

This distinction, by which the words oriental and eastern that in themselves have exactly the same meaning but are used as labels to describe two different realities, is impossible to translate in most other languages, and is not universally accepted even in English. These churches are also referred to as pre-Chalcedonian or now more rarely as non-Chalcedonian or anti-Chalcedonian. In languages other than English other means are used to distinguish the two families of Churches. Some reserve the term "Orthodox" for those that are here called "Eastern Orthodox" Churches, but members of what are called " Oriental Orthodox " Churches consider this illicit.