Out of the large number of heresiologists who wrote during the first centuries, why concentrate on the Adversus haereses of Irenaeus, the Elenchos of Hippolytus, and the Panarion of Epiphanius? The answer, in a nutshell, is that these works are available ; they are typical ; and they each took on ‘all the heresies’ of their own day.

They are available – that is, they survived. Justin wrote a Syntagma dealing also with all heresies and so did Hippolytus. Unfortunately, both are lost, and efforts to reconstruct them have obviously not succeeded in giving them back to us in their entirety. At best we might identify generically the heresies they refuted and infer something of the influence of these now lost works on the history of heresiology. It is not possible, however, to gain a clear idea of the arguments they used to counter their opponents.

Second, the Adversus haereses, the Elenchos, and the Panarion are typical representatives of the literary genre called ‘heresiology’. These works offer us excellent illustrations of what heresiology was in three successive centuries, and they allow us to follow the development of heresiology in that period. Moreover, they had a decisive and lasting influence on the fixing of the style of Christian polemics. (Their respective sources or their interdependence are not of primary concern here, although at times it will be useful to indicate the probable source of their ideas ; but our main interest is in the authors themselves. Each is seen as representing one major moment in the heresiological tradition).

Third, all three did battle with all heresies they knew, not only with particular heresies. This distinguishes them from heresiologists like Tertullian, Theophilus of Antioch, or Origen who took aim at one or another chosen target (Marcion or the Valentinians).

After Epiphanius heresiology betrays a depletion of energies. Pseudo-Tertullian, Filastrius of Brescia, Theodoret of Cyrus, also writing against all heresies, rely primarily for their information on Hippolytus’s Syntagma. Filastrius and Theodoret do not directly depend on Epiphanius ; they rather parallel him, and do not expand our knowledge of early heresies. The same may be said of Augustine ; he knew the ‘Anakephalaioseis’ of the Panarion and it is on them that he based his information in his De haeresibus. After Epiphanius no fresh knowledge of ancient heresies can be expected. New methods of dealing with heretics will indeed be developed. (But a study of these methods would include medieval heresiology up to the Reformation, which is beyond the scope of the present study. We are interested here in understanding the methods of dealing with ancient heresies).

Gérard Vallée, ‘A study in Anti-Gnostic polemics: Irenaeus, Hippolytus, and Epiphanius’, Introduction; in “Studies in Christianity and Judaism: 1”, pp. 4-6. Canadian Corporation for Studies in Religion, 1981.