That there existed a close connection between the gnostics and the Gospel according to John, or between 'gnosticism' and Johannine Christianity, is axiomatic in the modern study of ancient Christianity. The interpretation of this relationship has supplied a major building block in many presentations of the rise of the Christian movement. As I noted in the Introduction, the second-century evidence of a relationship between John and the early Christian gnostics and Valentinians is also profoundly linked with common views of the reception of that Gospel among the non-gnostic or orthodox churches in the second century. A major aspect of this is the view that gnostic use of and affinity for John precipitated or perpetuated a long-standing attitude of suspicion or antagonism towards that Gospel, a phenomenon we may, for convenience, call 'orthodox Johannophobia'. In many sections of the academy this way of viewing the evidence has practically become, in Kuhnian terms, 'normal science'. In order to understand the rise of this commonplace and its authority in recent scholarship, I catalogue here some important contributions on the subject by a number of prominent scholars of the past seventy years or so, the main architects and builders of the consensus, as well as its main critics.