Heterodox / condemned
c. 120–180 · 2nd c. · 3 works
Tatian the Assyrian (c. 120–180) was a second-century Christian apologist and writer of Assyrian or Syrian origin from the eastern reaches of the Roman world. Trained in Greek rhetoric and philosophy, he traveled to Rome, where he embraced Christianity and became a pupil and associate of Justin Martyr.
Born in the East and educated in Greek learning, he was drawn at Rome by the simplicity of the Christian Scriptures and attached himself to Justin's circle. After Justin's death (c. 165) he returned eastward and, by report, fell away from orthodoxy, founding or joining the rigorist, ascetic Encratite movement.
His principal surviving work is the Diatessaron, a harmony weaving the four Gospels into a single continuous narrative, which long served as the standard Gospel text of the Syriac Church; he also wrote the Address to the Greeks (Oratio ad Graecos), an apology sharply critical of Greek culture and philosophy.
On account of his later Encratism he is regarded by the sources as having lapsed into heresy after breaking with the Church; though counted among the early apologists, he is not venerated as a saint.
Sources: Encyclopædia Britannica — Tatian · Catholic Encyclopedia (New Advent) — Tatian