In his essаy оn the Stilling оf the Stоrm, Gunther Bornkаmm remаrks that biblical scholarship in his day had "put an end to the fiction" that we could discover a true picture of the historical Jesus that was "untouched by any kind of 'over-painting' through the faith of the Church." Which criticism would biblical scholarship have used in Bornkamm's day to come to such a conclusion?