This article presents a new reading of the polemical strategies and arguments embodied in the “anti-Jewish” tractate by the converted bishop of Burgos, Pablo de Santa María (c.1352–1435), the Scrutinium scripturarum (c.1432). It suggests the Scrutinium reflected a unique polemical dynamic that emerged between converts and Jews following the mass conversions of 1391 and the early fifteenth century, regarding the spiritual assimilation of converts to their new faith. Grappling with the new challenges faced by converts, the Scrutinium articulated a Christian approach toward rabbinic traditions and Jewish skepticism that differed dramatically from the scholastic–polemical traditions that were employed at the disputation of Tortosa. Its introduction of rabbinic esotericism provided its Latin-reading audience new historical and theological grounds for the integration of rabbinic authority within Christian scholarship and history. In doing so, it embodied what could be considered a distinct “converso voice,” which challenged the customary religious boundaries between Judaism and Christianity.