Irenaeus of Lyons wrote his Against Heresies c. 175-185 CE. His work is invaluable to modern scholarship in the attempt to recover the content of Gnostic teachings in the second century. Irenaeus also provides the first explicit witness to a four-fold gospel canon.
Mary Ann Donovan writes (The Anchor Bible Dictionary, v. 3, p. 457):
Irenaeus' major extant writing is the Adversus Haereses (the full title of which is the Refutation and Overthrow of Knowledge falsely so-called). Its composition is dated ca. 180 from the succession lists in which the author names Eleutherus (ca. 174 - ca. 189) as current bishop of Rome (Haer. 3.3.3), although it seems from remarks Irenaeus makes in the prefaces to Haer. 3 and 4 that he followed the practice of sending on the separate books of the work as they were completed. The other complete extant work is the Demonstration [or Proof] of the Apostolic Preaching. It was written after at least the earlier books of Adversus Haereses, to which reference is made in chap. 99. An Armenian version of this long-lost work was discovered in 1904, and Smith (1952: 4-11) discusses its textual history. Eusebius (ca. 263-ca. 339) is the principal source for our knowledge of the lost works of Irenaeus. These include at least the treatises "On the Ogdoad" and "Concerning Knowledge" and letters "On Schism" and "On the Monarchy [of God]" (Eus. Hist. Eccl. 5.20.1), as well as the full text of the letter to Victor already mentioned [c. 188 to c. 198].
Some of the fragments presented by Roberts-Donaldson are suspect. Johannes Quasten writes, "The fragments which Ch. M. Pfaff published in 1715, allegedly from manuscripts in Turin, were proved to be forgeries by A. Harnack (TU 20,3. Leipzig, 1900)." (Patrology, v. 1, p. 293) I present my own collection of quotes from Eusebius, with the original Greek and the English translation in the Loeb Classical Library, as a reliable source for the fragments of Irenaeus. There is also a fragment of a letter sent by Irenaeus to Pope Victor preserved in Syriac that is generally accepted as authentic.
There is an effort to bring the Latin text of Irenaeus online, requesting volunteers to help with proofreading.
Go to the Chronological List of all Early Christian Writings
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