The Chalcedonian Definition

The Chalcedonian Definition is the ecumenical confession on the person of Christ. Adopted at the Council of Chalcedon in 451, it settled the Christological controversies of the fifth century by confessing Christ as one Person (hypostasis) in two natures (physeis), fully God and fully man, the natures united "without confusion, without change, without division, without separation."

Each of those four negations rules out a specific error — Eutychianism's fusion of the natures, Apollinarianism's diminished humanity, Nestorianism's division of the Person, and adoptionism's denial of a unified subject. The Definition is received as authoritative by Roman Catholic, Eastern Orthodox (Chalcedonian), Lutheran, Anglican, and Reformed churches; it is quoted at length in the Westminster Confession (Ch. 8) and the Belgic Confession (Art. 19). AskCredo cites Chalcedon on questions about the two natures of Christ, the hypostatic union, the communicatio idiomatum, and the boundary between orthodox Christology and its historic alternatives.

Questions on AskCredo that cite the Chalcedonian Definition. Creeds are short confessional summaries affirmed by the historic church — they are cited as whole texts rather than by chapter or article.