One of the issues consistently plaguing New Testament scholars is the date of the Gospel of John. No consensus exists on this thorny dilemma. Looking at the world around the Bible, extrabiblical testimony often provides evidence for such questions. Insights drawn from Irenaeus are used by Lewis to help shed light on the topic. Noting the extent to which Irenaeus bears on the fourth Gospel, Lewis discusses the potential authors of John that could have been known by Irenaeus. Ending with modern conclusions to the issue, Lewis provides a useful summary of state of Irenaeus studies around the beginning of the twentieth century.