The attempt has been made in modern times to set aside Justin's testimony, on the alleged ground that he quotes not from our canonical gospels, but from some other writings. The groundlessness of this supposition is manifest at first sight. Justin had visited the three principal churches of Rome, Alexandria, and Ephesus. It is certain that he knew what gospels were received by them in his day as authentic, and that these are the very gospels which he quotes, affirming that they were the writings of apostles and their followers. Now, that the gospels which Justin used should have been wholly supplanted by others in the days of Irenaeus, who was of full age at the time of Justin's death, is incredible. But Irenaeus, in common with Clement, Tertullian, and others, quotes our four canonical gospels as alone possessing apostolic authority, and as having been always received by the churches. It follows that the "Memoirs" of Justin must be the same gospels. We cannot conceive that in this brief period an entire change of gospels should have been made throughout all the different and distant provinces of the Roman empire, at a time when concerted action through general councils was unknown; and that, too, in so silent a manner that no record of it remains in the history of the church. The supposition that the gospels known to Justin were different from those received by Irenaeus ought not to be entertained without irrefragable proof. But no such proof exists. "An accurate examination in detail of his citations," says Semisch, Life of Justin Martyr, 4. 1, "has led to the result that this title"--the Memoirs of the Apostles--"designates the canonical gospels--a result in no way less certain because again called in question in modern days."