To the Monks of Constantinople.
There is nothing new or surprising in the fact that the men who have made their tongues weapons against our God and Saviour should also aim their shafts of falsehood against His right minded servants. It must needs be that the servants who grieve sorely at the outrage inflicted on their Master should share it. That so it should be they have been forwarned by their Lord Himself, Who consoles His holy disciples with the words “If they have persecuted me they will also persecute you.” “If they have called the Master of the house Beelzebub, how much more shall they call them of His household.” Then He cheered them by pointing out that calumny is easily detected, for He went on “There is nothing covered that shall not be revealed and hid that shall not be known.” I have often seen the truth of the divine prediction, but I see it with special clearness now. The authors of the calumny against me, who have bought my destruction for large sums of money, have been distinctly seen to be involved in the unsoundness of Valentinus and Bardesanes. They had hoped to cloke their own iniquity if only they could whet their tongues on the hone of falsehood in order to wound me. For ever since I saw that the heresy long ago extinguished had been renewed by these men I never ceased to cry aloud, bearing my testimony in private and in public, as well in social gatherings as in the temples of God, and strive to confute their conspiracy against the faith. They have consequently poured out their insults on my head, and allege that I preach two sons. But they ought to have convicted me to my face, not slandered me behind my back. They have done just the contrary. They tied me hand and foot at Cyrus by the imperial decree; they compelled the very righteous judges to condemn me without a trial, and delivered their most equitable sentence against a man who was five and thirty stages away. Such treatment was never suffered by any criminal charged with witchcraft or robbery of the dead, by murderer or by adulterer. But for the present I will leave the judges alone, for the Lord is at hand “Who judges the world with righteousness and the people with his truth;” Who exacts an account not only of words and deeds, but even of evil thoughts. But think it right to refute the false charge which has been made. What proof have they of my asserting two sons? Had I been one of the silent kind there might have been some ground for the suspicion, but my task has been to contend on behalf of the apostolic decrees, to bring the pasture of instruction to the Lord's flocks, and to this end I have written five and thirty books interpreting the divine Scripture, and proving the falsehood of the heresies. The falsehoods these men have concocted are therefore easy of refutation. Tens on tens of thousands of hearers testify that I have taught the truth of the doctrines of the Gospel, and for any one who likes to bring them to the test my writings lie before the world. Not on behalf of a duality of sons, but of the only begotten Son of God, against the heathen, against Jews, against the recipients of the plague of Arius and Eunomius, against the supporters of the madness of Apollinarius, against the victims of the corruption of Marcion, I have never ceased to struggle; trying to convince the heathen that the Eternal Son of the ever living God is Himself Creator of the Universe; the Jews that about Him the prophets uttered their predictions, the Arians and Eunomians that He is of one substance, of one dignity and of equal power with the Father; Marcion's mad adherents that He is not only good but just; and Saviour not, as they fable, of another's works, but of His own. Once for all, fighting against each heresy, I charge men to fall down and worship the one Son.
And what need is there of many words, when it is possible to refute falsehood in few? We provide that those who year by year come up for holy baptism should carefully learn the faith set forth at Nicæa by the holy and blessed Fathers; and initiating them as we have been bidden, we baptize them in the name of the Father and of the Son and of the Holy Ghost, pronouncing each name singly. Furthermore when performing divine service in the churches, both at the beginning and the decline of day and when dividing the day itself into three parts, we glorify the Father the Son and the Holy Ghost. If, as our slanderers allege, we preach two sons, which do we glorify and which do we leave unworshipped? It were the wildest folly to believe that there are two sons, and to give the doxology to one alone. And who is so distraught as, while hearing the words of the divine Paul “one Lord, one faith, one baptism,” and again “there is one Lord Jesus Christ by Whom are all things,” to lay down the law at variance with the teaching of the Spirit, and cut the one in two. But I am prating unnecessarily, for these men, nurtured in falsehood as they are, do not even dare to assert that they have ever heard me say anything of the kind; but they affirm that I preach two sons because I confess the two natures of our Master Christ. And they refuse to perceive that every human being has both an immortal soul and a mortal body; yet no one has hitherto been found to call Paul two Pauls because he has both soul and body, any more than Peter two Peters or Abraham or Adam. Everyone recognises the distinction of the natures, and does not call one man two Pauls. Precisely in the same way, when styling our Lord Jesus Christ the only begotten Son of God, God the Word incarnate, both Son of God and Son of Man, as we have been taught by the divine Scripture, we do not assert two sons, but we do confess the peculiar properties of the Godhead and of the manhood. The party however who deny the nature assumed of us men cannot hear these arguments without irritation.
It is only right that I should point out from what sources they have derived this impiety. Simon, Menander, Cerdo, and Marcion absolutely deny the incarnation, and call the birth from a Virgin fable. Valentinus, however, Basilides, Bardesanes, and Harmonius and their following, accept the conception of the Virgin and the birth; but they deny that God the Word took anything from the Virgin, but made as it were a transit through her as through a conduit, and appeared to mankind in semblance only, and seeming to be a man, in like manner as He was seen by Abraham and certain others of the ancients. Arius and Eunomius on the contrary held that He assumed a body, but that the Godhead played the part of the soul, in order that they may attribute to it what was lowly in His words and deeds. Apollinarius did indeed assert that He assumed a soul with the body, not the reasonable soul, but the soul which is called animal or phytic. Their contention is that the Godhead took the part of the mind. He had learned the distinction of soul and of mind from the philosophers that are without while divine Scripture says that man consists of soul and body. For we read “And the Lord God formed man of the dust of the ground and breathed into his nostrils the breath of life and man became a living soul.” And the Lord in the sacred Gospels said to His apostles “Fear not them which kill the body but are not able to kill the soul.”
Source: Letters (New Advent)