But that Harmony, as we have also seen, included at least our three Synoptics.

The evidence (which we shall consider presently) for the use of the fourth Gospel by Tatian is so strong as to make it improbable that that work was not included in the Diatessaron.

The fifth work, alluded to by Victor of Capua, may possibly have been the Gospel according to the Hebrews.
2.
Just as the interest of Tatian turns upon the interpretation to be put upon a single term 'Diatessaron,' so the interest of Dionysius of Corinth depends upon what we are to understand by his phrase 'the Scriptures of the Lord.' In a fragment, preserved by Eusebius, of an epistle addressed to Soter Bishop of Rome (168-176 A.D.) and the Roman Church, Dionysius complains that his letters had been tampered with.

'As brethren pressed me to write letters I wrote them.

And these the apostles of the devil have filled with tares, taking away some things and adding others, for whom the woe is prepared.