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.
§ 165. The Ignatian Controversy.
The letters of Ignatius have received a good deal of scholarly attention and comment, according to Schaff, partly because they exist in significantly different versions, partly because of the statements about bishops (Schaff 2014, 20760). Between 1495 and 1498, a total of 15 letters were identified and published. However, by the time of Calvin, most were rejected as inauthentic. In the mid 1600s the seven letters known to Eusebius were published in the short versions which Schaff considers authentic (Schaff 2014, 20784). He does detail scholarshs who accept the authenticity and those who reject it for various reasons. Schaff does find considerable internal evidence for the early dating of the short versions. Particularly, they cite Scripture seldom, the attack Gnosticism based on its early forms, they speak indefinitely about specific theological topics, and they make no mention of Roman primacy in the fresh and hopeful episcopacy (Schaff 2014, 20813).
A Syriac text, published in the mid 800s, seems early. It lacks some of the potentially offensive parts found in the Greek text (Schaff 2014, 20828). However, the Syriac text is significantly different from the Greek text. For this reason, and because Eusebius described seven letters, Schaff considers the short Greek version as the most authentic.