Letters of the Blessed Theodoret,
CXXI. To Anatolius the Patrician.
The Lord who overlooks and governs all things has shewn both the apostolic truth of my doctrines, and the falsehood of the slander laid at my door. For the writings sent from the right godly and holy lord Leo, archbishop of Great Rome, to Flavianus of holy memory and to the rest assembled at Ephesus, are entirely in harmony with what I myself have written and have always preached in church. So soon therefore as I had read them, I praised the loving-kindness of the Lord, in that He had not wholly forsaken the churches, but had protected the spark of orthodoxy; or—shall I not rather say?—not a spark, but a very great torch, such as might enkindle and enlighten the world; for he has truly, in his writings, observed the apostolic stamp, and in them we have found at once what has been delivered by the holy and blessed prophets and apostles, and their successors in the preaching of the Gospel, and moreover the holy Fathers assembled at Nicæa. By these I confess that I abide, and indict all who hold other doctrines as guilty of impiety. Side by side with these writings of mine I have set one of the letters sent by him to Ephesus, to the end that when your excellency reads them you may remember the words which I have often spoken in church, may recognise the harmony of the doctrines, and may hate the utterers of the lie as well as those who have set up their new heresy in opposition to the doctrines of the Apostle.
 This letter may be dated shortly after Letter CXIX. Garnerius points out that it contains a short summary of the orthodox tradition, but makes no mention of the council of Ephesus in 431.