IRENAEUS, bishop of Lyons at the end of the 2nd century, was one of the most distinguished theologians of the anteNicene Church. Very little is known of his early history. His childhood was spent in Asia Minor, probably at or near Smyrna; for he himself tells us (Adv. haer. iii. 3, 4, and Euseb. Hist. Eccl. v. 20) that as a child he heard the preaching of Polycarp, the aged bishop of Smyrna (d. February 22, 156). But we do not know when this was. He can hardly have been born very long after 130, for later on he frequently mentions having met certain Christian presbyters who had actually seen John, the disciple of our Lord. The circumstances under which he came into the West are also unknown to us; the only thing which is certain is that at the time of the persecution of the Gallic Church under Marcus Aurelius (177) he was a presbyter of the church at Lyons. In 177 or 178 he went to Rome on a mission from this church, to make representations to Bishop Eleutherius in favour of a more lenient treatment of the Montanists (see MONTANISM. ; Eus. v. 4. 2). On his return he was called upon to undertake the direction of the church at Lyons in the place of Bishop Pothinus, who had perished in the persecution (Eus. v. 5. 8). As bishop he carried on a great and fruitful work. Though the statement of Gregory of Tours (Hist. Franc, i. 29), that within a short time he succeeded in converting all Lyons to Christianity, is probably exaggerated, from him at any rate dates the wide spread of Christianity in Lyons and its neighbourhood. He devoted particular attention to trying to reconcile the numerous sects which menaced the existence of the church (see below). In the dispute on the question of Easter, which for a long time disturbed the Christian Church both in West and East, he endeavoured by means of many letters to effect a compromise, and in particular to exercise a moderating influence on Victor, the bishop of Rome, and his unyielding attitude towards the dissentient churches of Africa, thus justifying his name of " peace-maker " (Eirenaios) (Eus. H.E. v. 24. 28). The date of his death is unknown. His martyrdom under Septimius Severus is related by Gregory of Tours, but by no earlier writer.
The chief work of Irenaeus, written about 180, is his " Refutation and Overthrow of Gnosis, falsely so called " (usually indicated by the name Against the Heresies) . Of the Greek original of this work only fragments survive; it only exists in full in an old Latin translation, the slavish fidelity of which to a certain extent makes up for the loss of the original text. The treatise is divided into five books: of these the first two contain a minute and well-informed description and criticism of the tenets of various heretical sects, especially the Valentinians; the other three set forth the true doctrines of Christianity, and it is from them that we find out the theological opinions of the author. Irenaeus admits himself that he is not a good writer. And indeed, as he worked, his materials assumed such unmanageable proportions that he could not succeed in throwing them into a satisfactory form. But however clumsily he may have handled his material, he has produced a work which is even nowadays rightly valued as the first systematic exposition of Catholic belief. The foundation upon which Irenaeus bases his system consists in the episcopate, the canon of the Old and New Testaments, and the rule of faith. With their assistance he sets forth and upholds, in opposition to the gnostic dualism, i.e. the severing of the natural and the supernatural, the Catholic monism, i.e. the unity of the life of faith as willed by God. The " grace of truth " ( the charisma), which the apostles had called down upon their first disciples by prayer and layingon of hands, and which was to be imparted anew by way of succession (Sta&oxri, successio) to the bishops from generation to generation without a break, makes those who receive it living witnesses of the salvation offered to the faithful by written and spoken tradition. The Scriptures of the Old and New Testaments, rightly expounded by the church alone, give us an insight into God's plan of salvation for mankind, and explain to us the covenant which He made on various occasions (Moses and Christ; or Noah, Abraham, Moses and Christ). Finally, the " rule of faith " (regida fidei), received at baptism, contains in itself all the riches of Christian truth. To distribute these, i.e. to elucidate the rule of faith as set forth in the creed, and further to point out its agreement with the Scriptures, is the object of Irenaeus as a theologian. Hence he lays the greatest stress on the conception of God's disposition of salvation towards mankind (oeconomia), the object of which is that mankind, who in Adam were sunk in sin and deaths should in Christ, comprised as it were in his person, be brought back to life. God, as the head of the family, so to speak, disposes of all. The Son, the Word (Logos) for ever dwelling with the Father, carries out His behests. The Holy Ghost (Pneuma), however, as the Spirit of wisdom for ever dwelling with the Father, controls what the Father has appointed and the Son fulfilled, and this Spirit lives in the church. The climax of the divine plan of salvation is found in the incarnation of the Word. God was to become man, and in Christ he became man. Christ must be God; for if not, the devil would have had a natural claim on him, and he would have been no more exempt from death than the other children of Adam; he must be man, if his blood were indeed to redeem us. On God incarnate the power of the devil is broken, and in Him is accomplished the reconciliation between God and man, who henceforth pursues his true object, namely, to become like unto God. In the God-man God has drawn men up to Himself. Into their human, fleshly and perishable nature imperishable life is thereby engrafted; it has become deified, and death has been changed into immortality. In the sacrament of the Lord's Supper it is the heavenly body of the God-man which is actually partaken of in the elements. This exposition by Irenaeus of the divine economy and the incarnation was taken as a criterion by later theologians, especially in the Greek Church (cf. Athanasius, Gregory of Nyssa, Cyril of Alexandria, John of Damascus). He himself was especially influenced by St John and St Paul. Before him the Fourth Gospel did not seem to exist for the Church; Irenaeus made it a living force. His conception of the Logos is not that of the philosophers and apologists; he looks upon the Logos not as the " reason " of God, but as the " voice " with which the Father speaks in the revelation to mankind, as did the writer of the Fourth Gospel. And the Pauline epistles are adopted almost bodily by Irenaeus, according to the ideas contained in them; his expositions often present the appearance of a patchwork of St Paul's ideas. Certainly, it is only one side of Paul's thought that he displays to us. The great conceptions of justification and atonement are hardly ever touched by Irenaeus. In Irenaeus is no longer heard the Jew, striving about and against the law, who has had to break free from his early tradition of Pharisaism.
Till recent times whatever other writings and letters of Irenaeus are mentioned by Eusebius appeared to be lost, with the exception of a fragment here or there. Recently, however, two Armenian scholars, Karapet Ter-Mekerttschian and Erwand Ter-Minassianz, have published from an Armenian translation a German edition (Leipzig, 1907; minor edition 1908) of the work "in proof of the apostolic teaching" mentioned by Eusebius (H.E. v. 26). This work, which is in the form of a dialogue with one Marcianus, otherwise unknown to us, contains a statement of the fundamental truths of Christianity. It is the oldest catechism extant, and an excellent example of how Bishop Irenaeus was able not only to defend Christianity as a theologian and expound it theoretically, but also to preach it to laymen.
BIBLIOGRAPHY. The edition of the Benedictine R. Massuet (Paris, 1710 and 1734, reprinted in Migne, Cursus patrologiae. Series Graeca, vol. v., Paris, 1857) long continued to be the standard one, till it was superseded by the editions of Adolph Stieren (2 vols., Leipzig, 1848-1853) and of W. Wigan Harvey (2 vols., Cambridge, 1857), the latter being the only edition which contains the Synac fragments. For an English translation see the Ante-Nicene Library. Of modern monographs consult H. Ziegler, Irenaeus, der Bischof von Lyon (Berlin, 1871); Friedrich Loofs, Irenaeus-Handschriften (Leipzig, 1888); Johannes Werner, Der Paulinismus des Irenaeus (Leipzig, 1889) ; Johannes Kunze, Die Gotteslehre des Irenaeus (Leipzig, 1891); Ernst Klebba, Die Anthropologie des heiligen Irenaeus (Miinster, 1894); Albert Dufourcq, Saint Irenee (Paris, 1904) ; Franz Stoll, Die Lehre des Heil. Irenaeus von der Erlosung und Heiligung (Mainz, 1905) ; also the histories of dogma, especially Harnack, and Bethune-Baker, An Introduction to the Early History of Christian Doctrine (London, 1903). (G. K.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)