What happens when an anti-Jewish polemic is written in a society shaped not by public Jews, but by converted Jews? This book answers that question through Fray Luis de Granada’s Fourth Part of the Introduction to the Symbol of the Faith (1583). Axel Kaplan Szyld shows that this treatise was not simply a work against Judaism, but a pro-converso apologetic that offered catechesis and integration as alternatives to inquisitorial repression and the segregation imposed by statutes of purity of blood. By reading Granada’s theology, sources, and networks together, the book reveals the unexpected functions of anti-Jewish polemic in early modern Iberia.