The statement of faith made by the Council of Chalcedon (451). It reaffirms the Christological definitions of Nicaea and Constantinople and formally repudiates the errors of Nestorius and Eutyches. It declares Christ to be one Person in two natures, the Divine of the same substance as the Father, the human of the same substance as us; these are united unconfusedly, unchangeably, indivisibly, and inseparably. By the end of the 7th cent. the Definition had been generally accepted in E. and W., except among the Oriental Orthodox Churches.