by Irenaeus of Lyons
Against Heresies, also known by its Latin title Adversus Haereses, or in Greek as Ἔλεγχος καὶ ἀνατροπὴ τῆς ψευδωνύμου γνώσεως, Elenchos kai anatropē tēs pseudōnymou gnōseōs, “On the Detection and Overthrow of the So-Called Gnosis“, was written in Greek about the year 180 by Irenaeus, the bishop of Lugdunum (now Lyon, France). In it, Irenaeus identifies and describes several schools of Gnosticism and argues that orthodox Christianity was passed down to him from the apostles who knew Jesus personally, while the Gnostics and Marcionites were distorting this apostolic tradition. Irenaeus also cites from most of the New Testament canon, along with noncanonical works such as 1 Clement and The Shepherd of Hermas; however, he makes no references to Philemon, 2 Peter, 3 John or Jude. He also provides a list of the Bishops of Rome, which includes Eleutherius, but not his successor Victor. Because of this and other reasons, Against Heresies can be dated to sometime between 174 and 189 AD. The earliest manuscript fragment of Against Heresies, P. Oxy. 405, dates to around 200 AD (Egypt Exploration Fund (1903). Grenfell, Bernard P.; Hunt, Arthur S. (eds.). The Oxyrhynchus Papyri. 3. Oxford. p. 10).