What is the Diatessaron?

Answer

The Diatessaron is an ancient literary work that merged the four Gospels of the New Testament into a unified narrative. The term Diatessaron can be interpreted as “Harmony of Four”; it is a transliteration of the Greek dia tessaron (“through the four Gospels”). The Roman historian Eusebius is credited with coining the name Diatessaron.

Compiled around AD 170 by Tatian, an Assyrian Christian apologist and disciple of Justin Martyr, the Diatessaron was not the initial of its kind but proved to be the most impactful. Fragments of the Diatessaron have been unearthed in Greek, Syriac, Arabic, Latin, and various other languages— including Old English. Tatian likely wrote in either Greek or Syriac, although the original language of the Diatessaron remains uncertain. While a complete copy of the Diatessaron has not survived to this day, the entire text can be reconstructed from diverse sources.

When composing the Diatessaron, Tatian closely followed the wording of the Gospels but arranged verses in a different sequence. He eliminated redundant information, retaining only one version of each parallel passage. Consequently, the feeding of the five thousand is mentioned just once in the Diatessaron, rather than four times. Tatian also omitted certain perceived contradictions in the Gospels, such as the differing genealogies in Matthew 1 and Luke 3. Additionally, the Diatessaron excludes the pericope adulterae (the story of the woman taken in adultery in John 8:1-11). The result is a condensed, singular narrative of Christ’s life—approximately three-quarters the length of the four canonical Gospels. The Diatessaron covers all but 56 verses of the canonical Gospels.

Initially, the four Gospels circulated independently within the early church.

Tatian’s Diatessaron consolidated all the Gospels into one convenient compilation. About twenty years after Tatian finished his work, Irenaeus, a significant figure in early church history, endorsed the Diatessaron as authoritative. This compilation became one of the most favored versions of the Gospels ever crafted. Over time, it was utilized by various groups including Catholic Christians, Judaic Christians, Syriac Christians, Manicheans, and missionaries. Its most significant influence was felt in Syria, where it served as the standard gospel text for many years until it was eventually supplanted by the Peshitta.

However, the Diatessaron is not without its challenges. It appears that Tatian included some content not present in the original four Gospels, like the apocryphal tale of a light shining on the Jordan River during Jesus’ baptism. Certain passages in the Diatessaron have been linked by church leaders to the Gospel of the Hebrews, the Gospel of the Ebionites, and other non-canonical writings.

Due to Tatian’s alterations to the Scriptures, some church authorities opposed the Diatessaron. Some objected to Tatian himself—being a prominent Encratite, a celibate vegetarian who refrained from all sexual activities. By the fifth century, the Diatessaron had lost favor among church leaders.

The primary significance of the Diatessaron today lies in its early testimony to the original Gospels. The four canonical Gospels—Matthew, Mark, Luke, and John—were acknowledged by the early church as divinely inspired, and considerable effort was evidently made to safeguard the texts and circulate them widely. Serving as a testament to the early church’s recognition of the Gospels, the Diatessaron occupies a prominent place in contemporary New Testament scholarship.