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
New Testament that there is not one sentence in the New Testament in which the [manuscript] is wholly uniform." Most of the variation took place within the first three Christian centuries. By the 4th century, textual "families" or types of text become discernible among New Testament manuscripts. A "text-type" is the name given to a family of texts with similar readings due to common ancestors and mutual correction. Many early manuscripts, however, contain individual readings from several different earlier forms of text. Modern texual critics have identified the following text-types among textual witnesses to the New Testament: The Alexandrian text-type is usually