Against Heresies by Saint Irenaeus

First transcribed:Adversus haereses, c. 180 c.e. (English translation, 1868)

Edition used:Against Heresies, translated by Alexander Roberts and James Donaldson, vol. 1 in the Ante-Nicene Christian Library. Edinburgh, Scotland: T & T Clark, 1880

Genre: Nonfiction

Subgenres: Biblical studies; didactic treatise

Core issues: Catholics and Catholicism; church; Gnosticism; salvation; truth

Overview

The main goal of Saint Irenaeus’s Against Heresies was to counteract Christian teachings he believed to be false and insidious. Most of those doctrines fell under the category of Gnosticism, a second century Christian movement that emphasized knowledge (from the Greek word gnosis) as the key to salvation. Irenaeus set out not only to show the absurdity of the Gnostic systems but also to warn against the ethical dangers of such systems. He did so in five books addressed to an anonymous reader.

Book 1 is largely a catalog of various heresies. Foremost among these is Valentinianism, a movement begun by Valentinus, a prominent Christian teacher in Rome in the middle of the second century. He expounded an elaborate cosmology in which the creator of the world was evil and thus all material things—including human bodies—were also evil. Those people who realized that they were spiritual and not material (including Valentinus and his followers) were the only ones who would experience salvation; the others (the majority of Christians) had an incomplete understanding of the truth. Irenaeus’s argument against the Valentinians takes two directions. First, he shows that the Valentinians pervert Scripture by taking it out of context and ignoring the plain sense of the text. Second, and more important, he argues that the Valentianian system attacks the unity of the church. Irenaeus emphasizes that the church must stand as a whole, “as if she had but one soul and heart.” Valentinians, however, extol individuality. Irenaeus’s stress on the unity of the church is the most prominent polemical aspect of the entire work. The rest of book 1 is a long catalog of other prominent Christian heresies, each of which Irenaeus describes and then attacks.

In book 2, Irenaeus elaborates on many of the points he made in the first book, arranging his discussion under theological topics. He confines himself primarily to the Valentinians, but he claims that the arguments against them are damning of other heresies. Irenaeus favors absolute monotheism over the polytheism of the Valentinians, stating that to believe in polytheism is logically absurd. He presents arguments against the many deities in which the Valentinians believe and chastises them for their numerological speculation and their distorted belief in the afterlife. In this book, Irenaeus first uses the phrase “rule of truth.” This phrase encapsulates the unity he emphasizes in book 1: Only one truth exists for Christians, and it is the one truth that has always provided guidelines for Christians.

Irenaeus turns to Scripture in books 3 and 4. Book 3 divides into two sections, one that highlights the monotheism taught in the Old Testament and one that emphasizes the unique manifestation of God in Jesus Christ. Before quoting Scripture, however, Irenaeus lays the foundation for its authority. What is crucial for Irenaeus and what helps illuminate his concept of Scripture is that the apostolic succession of church leaders, especially the episcopate at Rome, ensures the veracity of Christian teachings. It therefore provides parameters within which Scripture can receive proper interpretation. For Irenaeus, Scripture and apostolic succession form a conjoined stream. In this work are the earliest delineations of the two main sources of revelation in Catholicism: Scripture and tradition.

An important historical aspect of book 3 is Irenaeus’s argument for the completeness of the four Gospels. He is the first to argue for the authority of Matthew, Mark, Luke, and John alone. In a fairly elaborate narrative, he states that just as there are four winds of the earth and four corners of the earth, so also there should be four Gospels. As a corollary of this argument, he chastises Christians who read only one to the exclusion of the other three.

After he makes the case for apostolic and scriptural authority in book 3, Irenaeus shows in book 4 that the teaching of Jesus and his apostles meshes perfectly with the story of the Old Testament. The Valentinians, along with others in early Christianity (namely Marcion), made a sharp division between the person of Jesus and the God of the Old Testament. Irenaeus, in an important development for the early church, states that the God of the Old Testament and Jesus are inseparable and, furthermore, that they are incomprehensible apart from one another. Irenaeus marshals evidence for both ideas. He demonstrates that figures such as Moses and Abraham looked forward to the coming of Jesus as the Son of God. Conversely, he shows that Jesus himself adhered to the stories of the Old Testament and the God proclaimed there. Irenaeus elegantly displays the continuity between both testaments and shows how both are authoritative for Christianity.

Central to book 5 are the topics of incarnation and salvation. Referring often to Paul’s letters, Irenaeus shows that Jesus became fully human while losing none of his divine qualities. Because of the Incarnation, death, and Resurrection of Jesus, humans will also experience resurrection after death. This book contains the most pastoral passages of Against Heresies. Irenaeus’s disagreement with the heretics is not simply a matter of being proved correct. He believes that Gnostic teachings will lead unknowing Christians to their eternal damnation. In book 5, he explicitly states that Valentinus and other Gnostics are minions of Satan and that their doctrines, which are bereft of salvific power, will ultimately destroy those who follow them.

Christian Themes

The importance of Irenaeus’s Against Heresies transcends its historical polemics against Gnosticism. In making a case against Valentinians, Irenaeus developed the theological groundwork for what would become orthodox Christianity. He desired to make the church truly “catholic” (universal) and, in doing so, formulated important principles, especially creed, canon, and apostolic succession. Apostolic succession was necessary to create a common discourse among Christians. A definite canon was important for having a shared set of texts from which all could draw. A creed was vital for summarizing what bound Christians together. Behind all Irenaeus’s polemics lay an intense pastoral desire for the welfare of the church.

It would therefore be misguided to see Irenaeus as a bullying bishop trying to force his beliefs on others. What he disliked about Gnosticism was its dual tendencies toward rampant individualism and toward elitism. Although superficially inclusive—Gnostics seemingly put few constraints on their adherents—they clearly thought of themselves as a superior minority. Irenaeus’s catholicism attempts to clear out a space whereby all can be a part of the church, not just a select few.

Irenaeus’s desire for unity within the church shapes his understanding of both Scripture and salvation. At a time in Christian history when the Old Testament could easily have been discarded, Irenaeus advocates its role within Christianity. Because he believes God to be eternal and singular, the story of God’s relationship with humans cannot begin with Jesus. Rather, Jesus functions as the climax and fulfillment of God’s work on earth. Humans participate in that story by believing in Jesus and experiencing salvation. When Irenaeus claims that salvation occurs through the church alone, he highlights the uniqueness of Christian teachings. If God is one, then God must have one method of relating to humans, and this is through Christ. Irenaeus’s exclusive claim for Christianity comes from his conviction of the unity of God. What might strike the modern reader as vitriol should not overshadow Irenaeus’s pastoral aims. Behind all his harsh language, he exhibits a capacious vision of what an ideal church might be.

Sources for Further Study

Donovan, Mary Ann. One Right Reading? A Guide to Irenaeus. Collegeville, Minn.: Liturgical Press, 1997. A book-by-book reading guide to Against Heresies, with outlines and commentary.

Grant, Robert M. Irenaeus of Lyons. New York: Routledge, 1997. English translations of selected portions of Against Heresies with some useful introductory essays.

Norris, Richard A., Jr. “Irenaeus of Lyon.” In The Cambridge History of Early Christian Literature, edited by Frances Young, Lewis Ayres, and Andrew Louth. Cambridge, England: Cambridge University Press, 2004. A nice, brief overview of Irenaeus’s work within the context of early Christianity.

Osborn, Eric Francis. Irenaeus of Lyons. Cambridge, England: Cambridge University Press, 2001. The most comprehensive study in English of Irenaeus’s life and theology, with an emphasis on his rhetorical and aesthetic skills.