Although Theodoret, writing in the fifth century, says in the usual arbitrary manner of early Christian writers, that Tatian "excised" from his Gospel the genealogies and certain passages found in the Synoptics, he offers no explanation or proof of his assertion, and the utmost that can be received is that Tatian's Gospel did not contain them.(3) Did he omit them or merely use a Gospel which never included them? The latter is the more probable conclusion. Neither Justin's Gospel nor the Gospel according to the Hebrews contained the genealogies or references to the Son of David, and why, as Credner suggests, should Tatian have taken the trouble to prepare a Harmony with these omissions when he already found one such as he desired in Justin's Gospel? Tatian's Gospel, like that of his master Justin, or the Gospel according to the Hebrews, was different from, yet nearly related to, our canonical Gospels, and as we have already seen, Justin's Gospel, like Tatian's, was considered by many to be a harmony of our Gospels.(3) No
one seems to have seen Tatian's "Harmony," probably for the very simple reason that there was no such work, and the real Gospel used by him was that according to the Hebrews, as some distinctly and correctly called it. The name Diatessaron is first heard of in a work of the fourth century, when it is naturally given by people accustomed to trace every such work to our four Gospels, but as we have clearly seen, there is not up to the time of Tatian any evidence even of the existence of three of our Gospels, and much less of the four in a collected form. Here is an attempt to identify a supposed, but not demonstrated, harmony of Gospels whose separate existence has not been heard of. Even Dr. Westcott states that Tatian's Diatessaron "is apparently the first recognition of a fourfold Gospel,"(1) but, as we have seen, that recognition emanates only from a writer of the fourth century who had not seen the work of which he speaks. No such modern ideas, based upon mere foregone conclusions, can be allowed to enter into a discussion regarding a work dating from the time of Tatian.(2)
The fact that the work found by Theodoret in his diocese was used by orthodox Christians without