Diognetus, EPISTLE TO (EPISTOLA AD DIOGNETUM).—This beautiful little apology for Christianity is cited by no ancient or medieval writer, and came down to us in a single MS. which perished in the siege of Strasburg (1870). The identification of Diognetus with the teacher of Marcus Aurelius, who bore the same name, is at most plausible. The author’s name is unknown, and the date is anywhere between the Apostles and the age of Constantine. It was clearly composed during a severe persecution. The manuscript attributed it with other writings to Justin Martyr; but that earnest philosopher and hasty writer was quite incapable of the restrained eloquence, the smooth flow of thought, the limpid clearness of expression, which mark this epistle as one of the most perfect compositions of antiquity. The last two chapters (xi, xii) are florid and obscure, and bear no relation to the rest of the letter. They seem to be a fragment of a homily of later date. The writer of this addition describes himself as a “disciple of the Apostles“; and through a misunderstanding of these words the epistle has, since the eighteenth century, been classed with the writings of the Apostolic Fathers. The letter breaks off at the end of chapter x; it may have originally been much longer.
The writer addresses the “most excellent Diognetus”, a well-disposed pagan, who desires to know what is the religion of Christians. Idol-worship is ridiculed, and it is shown that Jewish sacrifices and ceremonies cannot cause any pleasure to the only God and Creator of all. Christians are not a nation nor a sect, but are diffused throughout the world, though they are not of the world, but citizens of heaven; yet they are the soul of the world. God, the invisible Creator, has sent His Child, by whom He made all things, to save man, after He has allowed man to find out his own weakness and proneness to sin and his incapacity to save himself. The last chapter is an exposition, “first” of the love of the Father, evidently to be followed “secondly” by another on the Son; but this is lost. The style is harmonious and simple. The writer is a practiced master of classical eloquence, and a fervent Christian. There is no resemblance to the public apologies of the second century. A closer affinity is with the “Ad Donatum” of St. Cyprian, which is similarly addressed to an inquiring pagan. The writer does not refer to Holy Scripture, but he uses the Gospels, I Peter, and I John, and is saturated with the Epistles of St. Paul. Harnack seems to be right in refusing to place the author earlier than Irenaus. One might well look for him much later, in the persecutions of Valerian or of Diocletian. He cannot be an obscure person, but must be a writer otherwise illustrious; and yet he is certainly not one of those writers whose works have come down to us from the second or third centuries. The name of Lucian the Martyr would perhaps satisfy the conditions of the problem; and the loss of that part of the letter where it spoke more in detail of the Son of God would be explained, as it would have been suspected or convicted of the Arianism of which Lucian is the reputed father. The so-called letter may be in reality the apology presented to a judge.
The editio princeps is that of Stephanus (Paris, 1592), and the epistle was included among the works of St. Justin by Sylburg (Heidelberg, 1593) and subsequent editors; the best of such editions is in Otto, “Corpus Apologetarum Christ.” (3d ed., Jena, 1879), III. Tillemont followed a friend’s suggestion in attributing it to an earlier date, and Gallandi included it in his “Bibl. Vett. PP.”, I, as the work of an anonymous Apostolic Father. It has been given since then in the editions of the Apostolic Fathers, especially those of Hefele, Funk (2d ed., 1901), Gebhardt, Harnack, and Zahn (1878), Lightfoot and Harmer (London, 1891, with English tr.). Many separate editions have appeared in Germany. There is an English translation in the Ante-Nicene Library (London, 1892), I. The dissertations on this treatise are too numerous to catalogue; they are not as a rule of much value.
Baratier and Gallandi attributed the letter to Clement of Rome, Bohl to an Apostolic Father, and he was followed by the Catholic editors or critics, Mohler, Hefele, Permaneder, Alzog; whereas Grossheim, Tzschirner, Semisch, placed it in the time of Justin; Dorner referred it to Marcion; Zeller to the end of the second century, while Ceillier, Hoffmann, Otto, defended the MS. attribution to Justin; Fessler held for the first or second century. These definite views are now abandoned, likewise the suggestions of Kruger that Aristides was the author, of Draseke that it is by Apelles, of Overbeck that it is post-Constantinian, and of Donaldson that it is a fifteenth-century rhetorical exercise (the MS. was thirteenth- or fourteenth-century). Zahn has sensibly suggested 250-310. Harnack gives 170-300.