Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 13. Ecclesiastical Literature of the Ante-Nicene Age, and Biographical Sketches of the Church Fathers.” sec. 159-204.
§ 174. The Other Greek Apologists. Tatian.
Tatian, who lived from 110-172, was a Christian philosopher, though Schaff observes that he eventually was somewhat Gnostic or at least an extreme ascetic (Schaff 2014, loc. 21690). He was led to the Christian faith as an adult, by means of the Hebrew Scriptures. One extant work is To the Greeks, probably written in Rome. Schaff sees this as a forceful and incisive work, showing especially the errors of Greek mythology (Schaff 2014, loc. 21700). Schaff provides us with a number of excerpts which show Tatian’s writing style. Schaff notes that Tatian’s other, very important, work is now lost, the Diatessaron, a harmony of the Four Gospels. It was once in wide circulation but cannot now be located, though there are reconstructions from translations (Schaff 2014, loc. 21745).