On Eutychianism

St. Flavian of Constantinople died ca. 449

Such a one, therefore, has now shown himself among us, Eutyches, for many years a presbyter and archimandrite , pretending to hold the same belief as ours, and to have the right Faith in him: indeed he resists the blasphemy of Nestorius, and feigns a controversy with him, but the exposition of the Faith composed by the 318 holy fathers, and the letter that Cyril of holy memory wrote to Nestorius, and one by the same author on the same subject to the Easterns, these writings, to which all have given their assent, he has tried to upset, and revive the old evil dogmas of the blasphemous Valentinus and Apollinaris. He has not feared the warning of the True King: Who so shall cause one of the least of these little ones to stumble, it was better that a millstone should be hanged about his neck, and that he should be sunk in the depth of the sea.  But casting away all shame, and shaking off the cloak which covered his error , he openly in our holy synod persisted in saying that our Lord Jesus Christ ought not to be understood by us as having two natures after His incarnation in one substance and in one person: nor yet that the Lord’s flesh was of the same substance with us, as if assumed from us and united to God the Word hypostatically: but he said that the Virgin who bare Him was indeed of the same substance with us according to the flesh, but the Lord Himself did not assume from her flesh of the same substance with us: but the Lord’s body was not a man’s body, although that which issued from the Virgin was a human body, resisting all the expositions of the holy Fathers. (Letter 22.3)

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 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 consubstantial with us or with her who bare him, according to the flesh. (Letter 26.1)