On the third passage he remarks that, unlike the author of the Fourth Gospel, 'Tatian here speaks of God, and not of the Logos.' Just so; but then he varies the preposition accordingly, substituting [Greek: hupo] for the Evangelist's [Greek: dia] to suit his adaptation. Our author also refers to 'the first chapters of Genesis;' but where is there any language in the first chapters of Genesis which presents anything like the same degree of parallelism? Here again, he is unable to impugn the coincidence, which is all the more remarkable because the words are extremely simple in themselves, and it is their order and adaptation which gives a character of uniqueness to the expression.
So much for the individual coincidences. But neither here nor elsewhere does our author betray any consciousness of the value of cumulative evidence. It is only necessary to point to the enormous improbability that any two writers should exhibit accidentally three such resemblances as in the passages quoted; and the inference will be plain.
It is not however in this testimony which his extant work bears to the Fourth Gospel, however decisive this may be, that the chief importance of Tatian consists. Ancient writers speak of him as the author of a Harmony or Digest of the four Gospels, to which accordingly he gave the name of Diatessaron. This statement however has been called in question by some recent critics, among whom the author of Supernatural Religion is, as usual, the most uncompromising. It is necessary therefore to examine the witnesses:—
1. In the first place then, Eusebius states definitely [277:1]—'Tatian composed a sort of connection and compilation, I know not how, of the Gospels, and called it the Diatessaron ([Greek: sunapheian tina kai sunagôgên ouk oid' hopôs tôn euangeliôn suntheis to dia tessarôn touto prosônomasen]). This work is current in some quarters (with some persons) even to the present day.'
This statement is explicit; yet our author endeavours to set it aside on the ground that 'not only is it based upon mere hearsay, but it is altogether indefinite as to the character of the contents, and the writer admits his own ignorance ([Greek: ouk oid' hopôs]) regarding them' [278:1].
His inference however from the expression 'I know not how' is altogether unwarranted. So far from implying that Eusebius had no personal knowledge of the work, it is constantly used by writers in speaking of books where they are perfectly acquainted with the contents, but do not understand the principles or do not approve the method. In idiomatic English it signifies 'I cannot think what he was about,' and is equivalent to 'unaccountably,' 'absurdly,' so that, if anything, it implies knowledge rather than ignorance of the contents. I have noticed at least twenty-six examples of its use in the treatise of Origen against Celsus alone [278:2], where it commonly refers to Celsus' work which he had before him, and very often to passages which he himself quotes in the context. It is not ignorance of the contents, but disparagement of the plan of Tatian's work, which the expression of Eusebius implies. The Diatessaron was commonly current, as we shall see presently, in the neighbouring districts: and it would be somewhat strange if Eusebius, who took a special interest in apocryphal literature, should have remained unacquainted with it.
2. Our next witness is overlooked by the author of Supernatural Religion. Yet the testimony is not unimportant. In the Doctrine of Addai, an apocryphal Syriac work, which professes to give an account of the foundation and earliest history of Christianity at Edessa, the new converts are represented as meeting together to hear read, along with the Old Testament, the New (Testament) of the Diatessaron' [278:3]. It seems clear from this notice that, at the time when the writer composed this fiction, the form in which the Evangelical narratives were commonly read in the churches with which he was best acquainted was a Diatessaron, or Harmony of Four Gospels. From internal evidence however it is clear that the work emanated from Edessa or its neighbourhood. The date of the fiction is less certain; but it is obviously an early writing. The St Petersburgh MS containing it is assigned to the sixth century, and the British Museum MSS to the fifth or sixth century [279:1]; while there exists an Armenian version said to have been made as early as the fifth century. The work itself therefore must have been written much earlier than this. There is indeed no good reason for doubting that it is the very Syriac document to which Eusebius refers as containing the correspondence of our Lord with Abgarus, and preserved among the archives of Edessa, and which therefore cannot have been very recent when he wrote, about A.D. 325 [279:2]. At the same time it contains gross anachronisms and misstatements respecting earlier Christian history, which hardly allow us to place it much earlier than the middle of the third century [279:3]. Whatever may be its date, the fact is important that the writer uses Diatessaron, adopted from the Greek into the Syriac, as the familiar name for the Gospel narrative which was read in public. Of the authorship of this work however he says nothing. This information we have to seek from other sources. Nor is it far to seek.
3. We are told that the most famous of the native Syrian fathers, Ephraem, the deacon of Edessa (who died A.D. 373 [280:1]), wrote a commentary on the Diatessaron of Tatian. Our informant is Dionysius Bar-Salibi, who flourished in the last years of the twelfth century, and died A.D. 1207. In his own Commentary on the Gospels, he writes as follows [280:2]:—
Tatian, the disciple of Justin, the philosopher and martyr, selected and patched together from the Four Gospels and constructed a Gospel, which he called Diatessaron, that is Miscellanies. On this work Mar Ephraem wrote an exposition; and its commencement was—In the beginning was the Word. Elias of Salamia, who is also called Aphthonius, constructed a Gospel after the likeness of the Diatessaron of Ammonius, mentioned by Eusebius in his prologue to the Canons which he made for the Gospel. Elias sought for that Diatessaron and could not find it, and in consequence constructed this after its likeness. And the said Elias finds fault with several things in the Canons of Eusebius, and points out errors in them, and rightly. But this copy (work) which Elias composed is not often met with.
This statement is explicit and careful. The writer distinguishes two older works, bearing the name of Diatessaron, composed respectively by Tatian and Ammonius. In addition he mentions a third, composed at a later date by this Elias. Of the work of Ammonius of Alexandria (about A.D. 220) Eusebius, as Bar-Salibi correctly states, gives an account in his Letter to Carpianus, prefixed to his Canons. It was quite different in its character from the Diatessaron of Tatian. The Diatessaron of Tatian was a patchwork of the Four Gospels, commencing with the preface of St John. The work of Ammonius took the Gospel of St Matthew as its standard, preserving its continuity, and placed side by side with it the parallel passages from the other Gospels [281:1]. The principle of the one work was amalgamation; of the other, comparison. No one who had seen the two works could confuse them, though they bore the same name, Diatessaron. Eusebius keeps them quite distinct. So does Bar-Salibi. Later on in his commentary, we are told, he quotes both works in the same place [281:2]. When therefore he relates that Ephraem wrote a commentary on the Diatessaron of Tatian, he is worthy of all credit. From the last witness we have learnt that the Diatessaron was commonly read in the churches of Edessa; and it was therefore most natural that this famous Edessan father should choose it for commenting upon.