Did John rely on a ‘signs source’ for his gospel?
Rudolf Bultmann (1971) set the agenda for modern source analysis of John by postulating a ‘signs’ source, a ‘discourse’ source and a ‘passion’ source to account for a sizeable percentage of John’s unique material. Only the signs-source ever commended itself to a large number of scholars…
Gilbert van Belle’s exhaustive survey of scholarship on a signs-source summarizes five arguments supporting its existence and five reasons that make him conclude the hypothesis to be improbable (1994: 366-376). In its favour are (1) the fact that the first two signs are numbered (John 2:11; 4:54), as if John were relying on a source containing all seven signs that he presents (the rest without numbering); (2) the possibility that John 20:31 reads like the end of a Gospel because it formed the end of the signs-source (and thus it highlights the positive value of these sēmeia); (3) certain stylistic peculiarities in John’s miracle narratives; (4) the homogeneity of the form of these narratives, which is distinct from the synoptic miracle stories, and (5) the seemingly different theology and Christology of these texts.
On the other hand, (1) John could have numbered his first two signs as easily as a source could have; the lack of further numbers does not really count for or against a separate source document. (2) Chapter 21 should be viewed as an epilogue designed to be an integral part of the Gospel. (3) There are more stylistic affinities between the miracle accounts and the rest of the Gospel than there are differences. (4) The form-critical homogeneity is equally attributable to John. (5) Why appeal to a source at all, especially when there are other explanations of the theological tensions? If the final editor of John were really correcting the theology of his source(s), why did he not simply remove all trace of it, or at least radically subordinate the strand of thought he inherited to his own? While it might seem to bolster the case for historicity to appeal to an early written source on which the fourth Gospel drew, the evidence is too slight for us to do so with any confidence.
…Pierson Parker’s famous tongue-in-cheek dictum (1956: 304) has proved prophetic: ‘Unlike the various parts of Matthew and Luke, the writings supposed to underlie John exhibit the same theology and the same language and style throughout. It looks as though, if the author of the Fourth Gospel used documentary sources, he wrote them all himself.’