Development of the New Testament canon a novelty in Irenaeus's time. "Against Heresies" 3.11.7 acknowledges that many heterodox Christians use only one gospel while 3.11.9 acknowledges that some use more than four. The success of Tatian's Diatessaron in about the same time period is "...a powerful indication that the fourfold Gospel contemporaneously sponsored by Irenaeus was not broadly, let alone universally, recognized." Irenaeus apparently quotes from 21 of the New Testament books and names the author he thought wrote the text. He mentions the four gospels, Acts, the Pauline epistles with the exception of Hebrews and Philemon, as well as the first epistle of Peter, and
Synoptic Gospels as the Hebrew logia mentioned by Papias, the Jewish–Christian gospels, and the Gospel of Marcion. Ancient sources virtually unanimously ascribe the synoptic gospels to the apostle Matthew, to Peter's interpreter Mark, and to Paul's companion Luke - hence their respective canonical names. A remark by Augustine at the beginning of the fifth century presents the gospels as composed in their canonical order (Matthew, Mark, Luke, John), with each evangelist thoughtfully building upon and supplementing the work of his predecessors—the Augustinian hypothesis (Matthew–Mark). This view (when any model of dependence was considered at all) seldom came into question until the late