An ascetic Syrian philosopher who composed the Diatesseron, one of the earliest & most influential gospel harmonies. Autobiographical remarks in his Oration to the Greeks indicate that Tatian left eastern Syria to become an itinerant scholar. He experimented with various schools of Greek philosophy, especially Stoicism, before reading the Septuagint, which led him to become a Christian. About the middle of the 2nd c. CE he became a disciple of the Christian philosopher Justin at Rome. After Justin was martyred (ca. 163 CE), Tatian championed severe communal standards of purity: rejecting all marriage, meat, and intoxicating beverages (even in the Eucharist). According to Irenaeus (Against Heresies 1.28.1) he was excommunicated by the Roman church about 172 CE and returned to his Syrian homeland, where he led a puritanical Christian sect known as the Encratites ("those who exercise self-control"). Yet, Tatian's interpretation of the gospels became widespread in both East & West through the popularity of his Diatesseron, which was translated into many native languages even before the four canonical gospels on which it was based.

[For details see W. L. Peterson's chapter on "Tatian's Diatesseron" in Helmut Koester, Ancient Christian Gospels: Their History & Development (London /Philadelphia: SCM Press/Trinity Press International, 1990), pp. 403-430].

Other On-line Resources:

• For Irenaeus' reference to Tatian, see Against Heresies 1.28 [from Ante-Nicene Fathers vol. 1; posted as e-text by New Advent.

• For Irenaeus' rebuttal to Tatian's theory that Adam is beyond salvation, see Against Heresies 3.23.

• Tatian - article from 1910 Catholic Encyclopedia (posted by New Advent).

• Tatian's Address to the Greeks -  translation of Tatian's Oration & other historical information about its author from Peter Kirby's Early Christian Writings.