Two things seem to me to be inquired into concerning these three epistles: first, whether they have a certain author; second, by what translator they were rendered into the Latin tongue. By right no one can doubt that all of them were in fact written by Nestorius, although no Greek text of any of them is extant; for Coelestinus, Cyril, Cassian, and Marius Mercator make mention of them, whose authority makes the matter a certain and trustworthy thing. Coelestinus, to the clergy and people of Constantinople (Council of Ephesus, ch. 19): 'Nestorius, concerning the virginal childbirth and concerning the divinity of Christ our God and Saviour, as though forgetful of His reverence and of the common salvation of all, preaches abominable things,
and persuades to things that ought to be shunned, as also his writings sent to us by himself, with his own subscription, and as also the report of my holy brother and fellow-bishop Cyril, sent to me through Possidonius the deacon his son, have disclosed.' And to John of Antioch (ibid., ch. 20): 'These things have reached us, the grief of the faithful pressing them upon us. These have been made public in the books which he himself had sent. And — what is of greater proof — these have been so intimated to us by epistles sent, fortified with the very subscription of the author, that it is no longer permitted to doubt.' And to Nestorius himself (ibid., ch. 18): 'Some time ago we received your letters, to which, hard pressed, we could give no answer. For they had to be translated into the Latin tongue:
which, though late, we now do,' etc. And a little after: 'Now considering both the complaint about you of the aforesaid brother, and your letters at last translated, containing open blasphemy.' Cyril, to John of Antioch, speaking of Nestorius (ibid., ch. 21): 'I had counselled him by letters that he should abstain from those depraved and perverse questions, and should follow the faith of the Fathers; but, supposing that I had written these things out of hatred, so far was he from having any reckoning at all of him who had written these things to his piety out of charity, that, thinking thus and speaking thus, he hoped that he could insinuate himself into the ears of the Romans also, and forestall them.'
For indeed in a lengthy letter, having embraced certain absurd doctrines and having sent them to my lord Caelestinus, the most pious bishop of the Roman Church, among other things against those who dissent from him he added these words as well: 'Without horror they call the holy Virgin the Mother of God' (Epistle 1, part 4). Besides these things he also sent certain quaternions of his own exegesis, and so forth. And a little after: 'When the letters had been read in the council—and especially those in which there can be no room for false accusation, for they contain his own subscription.' And to Juvenal (likewise, chapter 24):
Thinking, moreover, that he could draw the Roman Church to his own opinion, he wrote to my lord Caelestinus, and into these letters he inserted the perversity of his doctrines; he also sent many expositions, and so forth. Cassian (Book 1 On the Incarnation, chapter 3): 'For hence comes this, that by his interventions he fosters the complaints of the Pelagians, and by his writings he assists their causes.' And in another place (Book 2, chapter 2): 'You say therefore, whoever you are, you heretic, who deny that God was born of a virgin, that Mary, the mother of our Lord Jesus Christ—that is, the mother of God—cannot be so called, but is only the mother of Christ, not of God. For no one,' you say, 'gives birth to one older than herself' (Epistle 1, part 5). And again in another place (Book ...
...7, chapter 7): 'The second part of your perversity is either a blaspheming calumny or a calumniating blasphemy, in that you say, "Birth ought to belong to the one giving birth"—not unlike the former. For it differs more in words than in substance and in kind: since when the birth of God is treated, you say the same thing, "that one more powerful could not be born of Mary," as you said above (Epistle 1, part 4), "that one prior could not be begotten."' It is certain that the third letter was rendered into Latin by Marius Mercator; the question can pertain only to the first two—whether they had Cassian as their translator, or Dionysius Exiguus, or some other whatever. In favor of Marius is the great similarity of Latinity between these two letters and the third:
it also tells in his favor that the sentence 'They put to death together with the flesh the Deity of the Only-begotten,' and so forth, is found in the very same words in the letter of Cyril to the clergy residing at Constantinople, which Marius translated; and finally it tells in his favor that in them are employed expressions otherwise familiar to Marius—praedicatio, praedicatissimus, and the like. But in favor of Cassian is that he read these same letters sent by St. Leo, then archdeacon; and indeed at that very time when St. Caelestinus wrote that they had been translated; likewise that he cites fragments from them, expressed in no other words than those now read. Perhaps there might be someone who would attribute this version to Dionysius Exiguus, relying, as it seemed to him, on the testimony both of Cassiodorus and of Dionysius himself.
For that one wrote that the Council of Ephesus was rendered into Latin by Dionysius; this one hints that the faith of Cyril and the impiety of Nestorius had remained unknown to Latin speakers down to his own times, and that for this reason he had undertaken to translate Cyril's synodical letter. But in truth such letters were rendered into Latin in the year 430, or rather 429, seeing that the supreme pontiff writes that they were translated before his own reply to the letters of Nestorius, and the complete passages are read in the work of Cassian, which was composed in these times. Dionysius, however, is a whole century later, for he lived in the year 533.
Then Cassiodorus, just like Isidore Mercator, understood by the name 'Council of Ephesus' only the synodical letter of Cyril, together with the twelve anathemas. Finally Dionysius, since he flourished even after the Fifth Council itself, at a time when Ephesus had long since been put into Latin, either slipped through inadvertence in a word when he wrote the above, or had in view the impiety of Nestorius reviving in his own times.
Having therefore set aside this opinion, I would gladly incline to the side of Cassian, were it not that the lowliness of diction found in these Latin letters seems not sufficiently to agree with the loftiness and grandeur of speech that shines forth in the seven books On the Incarnation, and also in those fragments which Cassian rendered into Latin from the sermons of Nestorius; nor indeed do the two passages brought forward to the contrary sufficiently prove the matter at issue, for they were rendered word for word from the Greek, in such a way as it is fitting for all to express them in the same words. Nor do I think they were translated by Mercator, since at the time when they were being translated he was staying at Constantinople, where he presented the Commonitorium to the emperor in the year 429, toward the end.
It remains, therefore, that they be said to have been rendered into Latin by some unknown person: yet this does not stand in the way of their having to be placed in this location; for although the first two are not found in our manuscript codices, I nonetheless judged that they should be appended to the third, on account of the kinship of subject matter; and that they should be edited in a more corrected form than before, so that they may be understood by readers; and that they should be placed back into the common volume of the Works of Nestorius, so that the convenience of some of the learned may be served.