with their writings and tenets. The dangerous character of their teaching had been fully recognized by others, whom he modestly designates as multo nobis meliores; but these had been (iv. praef.) unable through ignorance of the Valentinian "rule" or system of doctrine to adequately refute it. That it was his first object to refute Valentinianism, and only in a secondary and occasional way to attack other heresies, is evident from the whole construction and arrangement of bk. i., which is almost exclusively occupied with the Valentinians, and in a great measure bk. ii. also. Irenaeus repeatedly observes that he who refutes the Valentinians at the same time refutes all other heresies (cf. ii. 31, 1) "destructis itaque his qui a Valentino sunt, omnis haereticorum eversa est multitudo," an assertion of which he proceeds (31, 1–35, 5) to give detailed proof, in reference to various heretical parties. Thus in the preface to bk. iv. he speaks of the "doctrina eorum qui sunt a Valentino" as a "recapitulatio omnium haereticorum," and in. bk. ii. of having taken them as an example of the way in which all heretics are to be refuted ("tanquam speculum habuimus eos totius eversionis "). In bks. iii. iv. and v. the circle of vision is enlarged. Taking the Scriptures for his guide, he goes through in order the fundamental doctrines of Gnosticism, and besides Valentinian dogmas reviews the cognate ones of other heretical schools, specially of the Marcionites but nowhere gives such a connected view and refutation of other Gnostic systems as of the Valentinian in bk. ii.
His sources were primarily the writings of the heretics themselves. In the preface of bk. i. he speaks of the ὑπομνήματα of disciples of Valentinus, and observes that he has been in personal communication with some of them. More particularly it is the school of Ptolemaeus, an ἀπάνθισμα τῆς Οὐαλεντίνου σχολῆς, whose dogmatic system he sets himself to describe. The detailed account (c. Haer. i. 1–7) describes its development in the Western or Italian form, and this from several writings, one of which Clemens Alexandrinus also made use of in the excerpta ex scriptis Theodoti, cc. 44–65. From another source were derived additional details, cc. 11 and 12, of various opinions within the Valentinian system and of Valentinus himself, Secundus, Ptolemaeus, and others; c. 13, 1–5, cc. 14 and 15 are concerned with Marcus, his magic arts and theories about the symbolism of letters and numbers, concluding with a citation of some Iambic Senarii, written against him by a "Divinae aspirationis Senior et Praeco veritatis" (ὁ θεόπνευστος πρεσβύτης καὶ κήρυξ τῆς ἀληθείας). The same authority is further designated, after the quotation, as "amator Dei senior," which Epiphanius expresses by ὁ θεοφιλὴς πρεσβύτης.
Two other sources, from which Irenaeus may have derived acquaintance with Gnostic opinions, have been conjectured by Harnack (Zur Quellenkritik der Geschichte des Gnosticismus, p. 56) for the information in bks. iii.–v. concerning the details of Marcion's system, which with the Valentinian is the heresy most frequently referred to in that portion. These were Marcion's own writings and a refutation of Marcion by a presbyter of Asia Minor.
It would be of great interest to obtain more exact impressions of those other presbyters to whose words and writings Irenaeus makes frequent reference. Besides the "God-loving elder," from whom he borrows the Iambic Senarii against Marcus, Irenaeus cites on various occasions from "presbyters and disciples of the apostles"; under which title, besides Polycarp, bp. Papias of Hierapolis must certainly be included. From bk. iv. of Papias's Λογίων κυριακῶν ἐξηγήσεις Irenaeus cites the saying traditionally attributed to our Lord on the alleged testimony of St. John concerning the glories of His millennial kingdom (v. 33, 3 sqq.).
Of the writings of Polycarp there is no certain trace in Irenaeus, but he held in faithful remembrance his oral utterances. He knows indeed several writings of the bp. of Smyrna (Ep. ad Florin. ap. Eus. v. 20) and specially mentions Polycarp's Ep. to the Philippians (Haer. iii. 3, 4). Of the works of Justin Martyr Irenaeus knew and used—besides the Syntagma against all Heresies, and the possibly identical Syntagma against Marcion—the first Apologies, without, however, citing it (Quellen der ältesten Ketzergeschichte, p. 63). From which of Justin's works the citation, v. 26, 2, is derived cannot be decided. With far greater confidence we may assume Irenaeus to have used the Memoirs of Hegesippus (iii. 3, 3; 4, 3, cf. Quellen der alt. Ketzergesch. p. 73), and he makes one citation from the Ep. of Ignatius to the Romans (v. 28, 4), but without mentioning his name.
Irenaeus's great work is divided into five books. Bk. i. contains a detailed account of the Valentinian system, together with a general view of the opinions of the other sects. Bk. ii. undertakes to exhibit the unreasonableness and self-contradiction of the doctrines of Valentinianism. His chief object here is to combat the doctrine of the Demiurge or Creator as a subordinate existence outside the Pleroma, of limited power and insight, and separated from the "Father" by an infinite chasm. He also controverts the Valentinian doctrine concerning the Pleroma and its antithesis the Kenoma, the theory of Emanations, of the Fall of Achamoth, and the formation of the lower world through the sufferings of the Sophia; and finally, at great length, the Gnostic teaching concerning souls, and the distinction between Psychici and Pneumatici. Bks. iii. iv. and v. contain the refutation of Gnostic doctrines from Holy Scripture, preceded by a short dissertation on the sources of Christian truth. The one foundation of the faith is the gospel transmitted first by oral tradition and subsequently committed to writing. The Gnostics allow neither the refutation of their doctrines out of Scripture nor disproof from tradition. Against the one they appeal to a secret doctrine handed down among themselves, against the other to their own higher knowledge (gnosis). Irenaeus meets them by stating the characteristics of genuine apostolic tradition as ensuring the right interpretation of Holy Scripture. The chief media and transmitters of this tradition are the apostolic churches and their episcopal succession from the apostles themselves (Haer. iii. 1–4). He proceeds to give the proof from
