Eusebius to Carpianus, (my) beloved brother in the Lord. Greetings.
Ammonius the Alexandrian, through truly much labor and zeal, presented to us the Fourfold Harmony:1 set in order next to the Gospel According to Matthew were the similar-sounding2 pericopes of the rest of the Evangelists, with the inevitable result that the continuing sequence of the three was utterly destroyed concerning the interconnection3 of readings.
But so that, while preserving entire the rest of the whole and the sequence, you may know the proper place in each Evangelist in which each is guided by love of truth to say like another, taking a starting-point from the work of the above-mentioned man, I have formed for you ten lists4 in total, attached below.
Of these, the first contains numbers in which similar things were said by the four: Matthew, Mark, Luke, John.
The second, in which the three: Matthew, Mark, Luke.
The third, in which the three: Matthew, Luke, John.
The fourth, in which the three: Matthew, Mark, John.
The fifth, in which the two: Matthew, Luke.
The sixth, in which the two: Matthew, Mark.
The seventh, in which the two: Matthew, John.
The eighth, in which the two: Luke, Mark.
The ninth, in which the two: Luke, John.
The tenth, in which each of them wrote in his own manner.5
This, then, is the description of the lists attached below. Their clear explanation is this. In each of the four Gospels, a number is written before each part, starting from the first, then second and third, and proceeding in order through the whole until the end of the books. For each number there is a preceding note in red showing in which of the ten lists the number happens to lie. For example, if it is a 1,6 clearly it is in the first, if a 2,7 in the second, and so on to the tenth.
If having opened one of the four Gospels, you may wish to know a certain desired chapter, and to know which have said similar things, and to find each specific place in which each like another was guided, in the pericope you’re holding, take the preceding number, and seek the passage in the list with the red note suggests; you’ll see immediately from those (headings) written before the head of the list how many and which ones spoke concerning what you seek. Having sought the numbers of the rest of the Gospels which are in the list, corresponding to the number you are holding, and by seeking the passage in its specific place in each Gospel, you will find them saying similar things.
1 δια τεσσαρων Not to be confused with the Diatessaron of Tatian. I choose here “fourfold harmony” as the translation to distinguish this and also to indicate what the phrase would probably have brought to mind with an educated listener. the term is borrowed from musical terminology, and designates “a series of four harmonic tones” (Metzer Canon, 114). Thus my translation. Another tempting translation is “synopsis,” as this is the term for modern works resembling that of Ammonius’ (e.g., Kurt Aland’s Synopsis of the Four Gospels).
3 lit., “web”
4 κανων I translate as “list” throughout rather than “canon.”
5 The absence for a list covering those pericopes peculiar to the trio Mark, Luke, John, and of the duo Mark, John, I have yet to see explained. The attraction to having twelve lists would have been irresistible, one would think, to so early a churchman.
Metzger, Bruce. The Canon of the New Testament. Oxford, 1987.
Oliver, Harold H. “The Epistle of Eusebius to Carpianus: Textual Tradition and Translation.” Novum Testamentum 3 (1959): 138-145.