Council of Constantinople I

Canon 1 makes the Nicene faith itself a fixed and irreformable standard and anathematizes named heresies by conciliar act. The creed's own appeals to Scripture — "rose again according to the Scriptures," the Spirit "who spoke by the prophets" — sit inside a document whose binding force is conciliar.

Canon 1 — "The Faith of the Three Hundred and Eighteen Fathers assembled at Nice in Bithynia shall not be set aside."

Where 325 had a bare clause, 381 gives the Spirit a full article: "the Lord and Giver-of-Life, who proceeds from the Father, who with the Father and the Son together is worshipped and glorified, who spoke by the prophets." That completes the Trinitarian confession without ever calling the Spirit God outright — the same reserve Basil practised. Canon 1 anathematizes the Pneumatomachi and Apollinarians by name.

WORTH CORRECTINGThere is no filioque. The text reads "who proceeds from the Father," full stop — the Western addition comes centuries later.

Creed — "the Lord and Giver-of-Life, who proceeds from the Father"

The creed makes baptism singular and remissive — "one Baptism for the remission of sins" — placing it in the article on the church alongside the resurrection hope. The canons work this out pastorally: Arians, Macedonians and Novatians are received by written renunciation and chrismation without rebaptism, while Eunomians, Montanists and Sabellians are received as heathen and baptized.

WORTH CORRECTINGAs with Nicaea, infants are nowhere in view. The regenerative and unrepeatable character is explicit; the paedo dimension is not.

Creed — "We acknowledge one Baptism for the remission of sins."