Paul Anderson, increasingly vocal (and the print equivalent) in the use of John in historical Jesus studies, has suggested that such a use might herald a fourth quest for the historical Jesus. Now if the arguments by Marsh, Casey, Allison, and Bermejo Rubio and others are right (and they probably are), namely, that the classifications in to quests and non-quest are deeply misleading, then, obviously, the ‘fourth quest’ is not the right term. And someone will come along and point out that x, y and z used John’s Gospel in the study of the historical Jesus.
Perhaps it is better to read historical Jesus scholarship (and indeed any scholarship) in terms of its historical context(s). In terms of the use John’s gospel, it might reasonably be argued that the polarisation in certain sections of biblical scholarship (see the secular v faith/evangelical arguments, everywhere passim) goes someway to explain this emphasis on the often ignored John and the quest. But it is not clear that is enough to permit the terminology of a new quest though…is it?