Early in this study, I presented a brief sketch of the legacy of Jewish polemical literature and thinking available to the earliest Jewish polemicists writing in medieval western Christendom. That legacy can hardly be called extensive. Nonetheless, Daniel J. Lasker has suggested that this legacy, the most significant elements of which stem from the Islamic world, in fact adumbrated all the significant lines of anti-Christian argumentation that would later surface in medieval western Christendom. Our close inspection of the earliest wave of Jewish polemical writings from medieval western Christendom has – I believe – substantiated Lasker's claim. We have tracked in considerable detail the wide-ranging argumentation our late twelfth- and thirteenth-century southern-French and northern-Spanish polemicists offered to their Jewish readers. This argumentation covered a broad spectrum of issues and was grounded in appeals to revealed truth, to human reason, and to empirical observation. There is in fact, in all this, no approach and no issue not anticipated in the prior legacy of anti-Christian argumentation.

This of course raises the question of what precisely has been innovated by our five Jewish authors, the question with which I closed the survey of earlier Jewish polemical materials. Lasker himself suggests, as noted, that “a full-scale critique of Christianity had to wait for an all-out Christian attack on Judaism in Christian countries.” We have seen that by the middle of the twelfth century such an attack was under way, culminating in an intensive missionizing campaign initiated in the 1240s.