 Isaac (Yitzḥak) Polqar was a Jewish Averroist who was active in northern Spain from the second half of the thirteenth century and the first half of the fourteenth century. Jewish Averroism refers in this context to Jewish philosophers from the thirteenth to the sixteenth century, whose worldview had two main characteristics: firstly, they adopted the philosophy of Ibn Rushd (Averroes), whom they considered the best interpreter of Aristotle. Secondly, they interpreted Judaism in light of Averroes’ Aristotelianism on the assumption that Judaism and true philosophy must always coincide. In addition to his initial goal of giving the principles of Judaism a radically naturalistic Averroistic interpretation, Polqar, in a more apologetic vein, sought to defend that interpretation from criticisms leveled against it by Christians and converts, as well as by members of his own Jewish community who held more traditional views. Polqar is best known as the main interlocutor of his former teacher,  Abner of Burgos  (see entry), especially after the latter converted to Christianity and used his expertise in Biblical, Talmudic, and philosophical texts to attack the faith of his birth.