The general object of the first book is to give a full exposition of the Gnostic doctrines(72). The first seven chapters contain a detailed account of the system of Valentinus, who was at that time the most fashionable teacher of those doctrines. The eighth gives the Valentinian explanation of numerous passages of Scripture, which they brought forward as corroborative of the truth of their system, although they did not pretend to rest it upon them; and the ninth refutes those explanations. The tenth points out the unity of Catholic doctrine, and the remaining chapters are occupied in exhibiting the discrepancies of the various Gnostic sects and teachers. The object of the second book is to overthrow the system, both in its principle and in its details, by demonstrating its contradictoriness and impossibility(73). The first nineteen chapters are occupied in the destruction of the system; the next five are a fuller refutation of their arguments in support of it than he had given in chapter nine of the first book; and the twenty‐sixth, twenty‐seventh, and twenty‐eighth lay down certain rules for the proper study of the Scriptures. The rest of the book is taken up with a fuller consideration and refutation of particular opinions held by Gnostics. Irenæus himself states it to be the object of the third book to confute the heretical system by Scripture, as containing in writing the undoubted doctrine of those apostles through whose preaching the economy of salvation was originally revealed, and from whom the Church received the doctrine she preached(74). But since the heretics appealed to tradition as interpreting Scripture, he likewise appeals to it in the second, third, and fourth chapters(75); and having shown that it is totally adverse to the heretical doctrine, he returns to the argument from Scripture(76), and carries it on by quotations briefly from the Old Testament, and more fully from the words of the evangelists and apostles, showing, to the end of the fifteenth chapter, that they knew but one God, and from thence to the end of the twenty‐second chapter, that they taught but one Jesus Christ, truly God and truly man. The twenty‐third is a refutation of Tatian’s opinion, that Adam was not saved; and the two last contain sundry general reflections. Our author had confined himself in the third book for the most part to the testimony of evangelists and apostles; he informs us, that his object in the fourth is to show that our Lord himself testified of only one God, his Father, the maker and governor of the world, the author of the old and new covenants, and the judge of all mankind(77). He does not carry on his argument with much regularity, and it would be difficult to give any useful analysis of it. But he discusses, towards the end, in chapters thirty‐seven, thirty‐eight, and thirty‐nine, the great question of the accountability of man, and the freedom of the will.