Abner of Burgos, or as he was afterwards called, Alfonso Burgensis de Valladolid (born about 1270, died about 1346), was well acquainted with biblical and Talmudical writings, occupied himself with science, and practiced medicine. His knowledge had destroyed his religious belief, and turned him not only against Judaism, but against all faiths. Troubled by cares for his subsistence, Abner did not obtain the desired support from his kinsmen in race. He was too little of a philosopher to accept his modest lot. His desires were extravagant, and he was unable to find the means to satisfy them. In order to be able to live in ease and splendor, Abner determined, when nearly sixty years of age, to adopt Christianity, although this religion was as little able to give him inward contentment as that which he forsook. As a Christian, he assumed the name of Alfonso. The infidel disciple of Aristotle and Averroes accepted an ecclesiastical office; he became sacristan at a large church in Valladolid, to which a rich benefice was attached, enabling him to gratify his worldly desires. He attempted to excuse his hypocritical behavior and his apostasy by means of sophistical arguments. Alfonso carried his want of conscientiousness so far that not long after his conversion to Christianity he attacked his former brethren in faith and race with bitter hate, and showed the intention of persecuting them. Owing to his knowledge of Jewish literature, it was easy for him to discover its weak points, employ them as charges against Judaism, and draw the most hateful inferences. Alfonso was indefatigable in his accusations against the Jews and Judaism, and composed a long series of works, in which he introduced arguments partly aggressive, partly defensive of his new faith against the attacks upon it by the Jews. In his abuse of Judaism, the Hebrew language, in which he composed with much greater ease than in Spanish, was made to do service. Alfonso had the brazen impudence to send one of his hateful writings to his former friend, Isaac Pulgar. The latter replied in a sharply satirical poem, and pressed him close in his polemical writings. The Jews of Spain had not yet become so disheartened as to suffer such insolent attacks in silence. Another less renowned writer also answered Alfonso, and thus a violent literary warfare broke out.