DIATÉSSARON. – A work by Taziano, in which the text of the four Gospels was fused into a single ordered narrative. The fact is reported to us by the historian Eusebius (Hist. eccl., IV, 29) and by other ancient writers. Of the work there have come down to us: 1) a brief fragment in Greek, found in 1933 among the ruins of Dura Europos on the Euphrates; 2) fragments of a Syriac version in quotations by Syriac writers and in the commentary of s. Efrem (which has come down to us in Armenian); 3) a complete Arabic version from the Syriac, dating from the 11th century (v. ABŪ 'L-FARAŪ IBN AT-TAJĪB); 4) a complete Latin reworking in the cod. Fuldense of the Vulgate, from which several Gospel harmonies of the Middle Ages in Latin, Italian, German, Dutch, and English are either descended or collateral branches.
As regards the order of the material, that is, of the Gospel events, documents 2–4 do not agree exactly, but they concur in what is characteristic and essential in Taziano’s arrangement: namely, that, on the framework of the Passovers mentioned in the Fourth Gospel, whose traditional chapters 5 and 6 he reverses, he reduces the public life of Jesus to a year and a few months, and groups all that Jesus did in Jerusalem toward the end around Palm Sunday. They also all agree in placing the washing of the feet before the Paschal supper and Judas’s departure before the institution of the Most Holy Eucharist. For the rest, the best witness, though incomplete, to the original order seems to be the commentary of s. Efrem, followed by the Arabic version; the Western branches depart from it more substantially.
As regards the textual wording, conditions are even worse. The Arabic version represents for us a Syriac text already conformed, in its material expression, to the Pēšīṭā, that is, to a revision made in the 5th century on the Greek then current in Antioch (v. GRECHE, VERSIONI DELLA BIBBIA). In the codex of Fulda, Vittore di Capua (ca. 546) replaced the primitive Latin translation with the Vulgate of s. Girolamo (382). The genuine text of Taziano has been preserved for us more faithfully, but fragmentarily and at third hand, in the commentary of s. Efrem and in the scant quotations of other Syriac writers. Hence the delicacy of the problems involved in using Taziano for the textual criticism of the Gospels.