The four canonical Gospels of the New Testament were decided upon fairly early in fledgling church’s career to be the only acceptable Gospels. One scholar places the upper limit of the final dating for the four-fold Gospel Canon at around the year 150. Frederick C. Grant, The Gospels: Their Origin and Their Growth 13 (1983) . This is only an upper limit, and the Gospels were probably finalized much earlier; but even 150 is relatively early in church history. The Gospels necessarily had to be finished around that time: unwritten texts cannot be canonized, and the contemporary agreement of Irenaeus, Tertullian, and Clement of Alexandria was that the canonicity of the four Gospels was accepted by the end of the second century. Tatian, who was writing even slightly before Irenaeus and the others also held a view of four Gospels. This hints that Justin Martyr (ca. 150) also held this view, because Tatian was his disciple. Most interestingly, however, are the clues found in the Shepherd of Hermas, which point to the four-fold Gospels as well as serving as a source for some of Irenaeus’ later ideas on the subject. The church widely regarded the Gospels as having been written by apostles or their followers rather early; and these texts were canonized quite soon after they were all written.