Against Heresies is a work of Christian theology written in Greek about the year 180 by Irenaeus, the bishop of Lugdunum (now Lyon in France). In it, Irenaeus identifies and describes several schools of Gnosticism, as well as other schools of Christian thought, and contrasts their beliefs with orthodox Christianity. The treatise remains historically important as one of the first unambiguous attestations of the canonical gospel texts and some of the Pauline epistles. Irenaeus argued 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.

Table of Contents:

Book I.

Book II: A rebuttal of the Gnostic systems employing philosophical arguments primarily rather than employing Scripture.

Book III: Rebuttal based on apostolic succession and tradition passed down of the faith; defense of the incarnation of Jesus; defense of the virgin birth.

Book IV: Demonstration that the God of the Old Testament is the God of the New Testament.

Book V: A defense of the physical resurrection and eternal judgement.