Council of Chalcedon

The Definition ratifies a chain of prior authorities — the Nicene creed as pre-eminent, the 150 fathers of Constantinople, Cyril's synodical letters, and Leo's Tome to Flavian — then forbids anyone to produce a different faith. It grounds itself in the prophets of old time, the teaching of Christ, and the creed of the fathers together. Canon 1 extends the same principle to church order.

WORTH CORRECTINGChalcedon is where the pattern is clearest: Scripture, prior councils, and named patristic documents are received as a single normative deposit.

Definition — "no one shall be suffered to bring forward a different faith, nor to write, nor to put together."

The definitive statement: one and the same Christ, perfect in Godhead and perfect in manhood, consubstantial with the Father as to his Godhead and consubstantial with us as to his manhood, made like us in all things sin excepted — to be confessed in two natures "unconfusedly, immutably, indivisibly, inseparably," the distinction of natures not taken away by the union but the property of each preserved in one person and subsistence.

WORTH CORRECTINGA textual crux worth knowing: the surviving Greek reads ek duo physeon ("of two natures") while the old Latin has in duabus naturis ("in two natures"), and the session record supports "in" — the bishops were asked to choose between Dioscorus, who accepted "of two natures" but not that there were two natures, and Leo, and answered "We believe as Leo."

Definition — "in two natures, unconfusedly, immutably, indivisibly, inseparably"