To the most holy and blessed father and fellow-minister Leo, Flavian greeting in the Lord.
Nothing, as you know, most beloved of God, is more precious to priests than piety and he right dividing of the word of truth. For all our hope and safety, and the recompense of promised good depend thereon. For this reason we must take all pains about the true Faith, and those things which have been set forth and decreed by the holy Fathers, that always, and in all circumstances, they may be kept and guarded whole and uninjured. And so it was necessary on the present occasion for us, who see the orthodox Faith suffering harm, and the heresy of Apollinaris and Valentinus being revived by the wicked monk Eutyches, not to overlook it, but publicly to disclose it for the people's safety. For this man: this Eutyches, keeping his diseased and sickly opinion hid within him, has dared to attack our gentleness, and unblushingly and shamelessly to instil his own blasphemy into many minds: saying that before the Incarnation indeed, our Saviour Jesus Christ had two natures, Godhead and manhood: but that after the union they became one nature not knowing(2) what he says, or on what he is speaking so decidedly. For even the union of the two natures that came together in Christ did not, as your piety knows, confuse their properties in the process: but the properties of the two natures remain entire even in the union. And he added another blasphemy also, saying that the Lord's body which sprang from Mary was not of our substance, nor of human matter: but, though he calls it human, he refuses to say it was con-substantial with us or with her who bare him, according to the flesh(3) .
And this notwithstanding that the acts of Ephesus(4) , in the letter written by the holy and ecumenical synod to the wicked and deposed Nestorius, contain these express words "the natures which came together to form true unity are indeed different: and yet from then both there is but one Christ and Son. Not as if the difference between the two natures was done away with through the union, but rather that these same natures, His Godhead and His Manhood perfected for us one Lord Jesus Christ, through an ineffable and incomprehensible meeting which resulted in unity." And this does not escape your holiness, who have no doubt read the record of what was done at Ephesus. Yet this same Eutyches attaching no weight to these words, thinks he is not liable to the penalties fixed by that holy and ecumenical synod. For this reason, finding that many of the simpler-minded folk were injured in their faith by his contention, upon his being accused by the devout Bishop Eusebius, and upon his attending at the holy council, and with his own mouth declaring what he thought to the members of the synod, we have deposed him for his estrangement from the true Faith, as your holiness will learn from the resolutions passed about him: which we have sent with this our letter. Moreover, it is fair in my opinion that you should be told this also that this same Eutyches, after suffering just and canonical deposition, instead of making amends for his earlier by his later conduct(5) , and appeasing God by careful penitence and many tears, and by a true repentance, comforting our heart which was greatly saddened at his fall: not only did not do so, but even made every effort to throw the most holy church of this place into confusion: setting up in public placards full of insults and maledictions, and beyond this addressing his entreaties to our most religious and Christ-loving Emperor, and these too over-flowing with arrogance and sauciness, whereby he tried to override the divine canons in everything.
But after all this had occurred, your holiness' letter was conveyed to us by the most honourable count Pansophius: and from it we learnt that the same Eutyches had sent you a letter full of falsehood and cunning, saying that at the time of trial he had presented letters of appeal to us, and to the holy synod of bishops who were then present, and had appealed to your holiness: this he certainly never did, but in this matter, too, he has been guilty of deceit, like the father of lies, thinking to gain your ear. Therefore, most holy father, being stirred by all that he has ventured, and by what has been done, and is being done against us and the most holy Church, use your accustomed promptitude as becomes the priesthood, and in defending the commonweal and peace of the holy churches, consent by your own letter(6) to endorse the resolution that has been canonically passed against him, and to confirm the faith of our most religious and Christ-loving Emperor. For the matter only requires your weight and support, which through your wisdom will at once bring about general peace and quietness. For thus both the heresy which has arisen, and the disorder it has excited, will easily be appeased by God's assistance through a letter from you: and the rumoured synod will also be prevented, and so the most holy churches throughout the world need not be disturbed. I and all that are with me salute all the brethren that are with you. May you be granted to us safe in the Lord, and still praying for us, O most God-Loving and Holy Father.