The church was by no means wide of the mark when it identified Jewish influences in the Albigensian movement or the Hussites in fifteenth-century Bohemia. Jews were active in the two forces which finally broke the church’s monopoly, the Renaissance and Reformation. They were the fermenting yeast. The populist accusations hurled against Jews in the Middle Ages were all, without exception, fantasy. But the claim that they were intellectually subversive had an element of truth.