Meanwhile Jewish learning was in nowise impaired by the unfavorable conditions which existed in almost every land of the exile, but still took its place in the vanguard of culture. Two men, both from Toledo, added to its luster; these were Abraham Ibn-Daud and Abraham Ibn-Ezra, who, dissimilar in character, aims, and in their life's history, were yet alike in their love for Judaism and for learning. Abraham Ibn-Daud Halevi (born about 1110, died a martyr 1180), who was a descendant on the maternal side of Prince Isaac Ibn-Albalia, was not only well versed in the Talmud, but was also conversant with all the branches of learning then cultivated. He also engaged in the study of history, both Jewish and general, as far as in its neglected state during the Middle Ages it was accessible to him. This branch of learning was but lightly esteemed by the Spanish Jews. He was a physician, and was a diligent explorer of the realm of science. Ibn-Daud possessed an intelligent, clear mind, which enabled him to penetrate with precision into the knowable, and to illumine the obscure. With brilliant perspicuity he gave expression to the most difficult ideas, and made them comprehensible. He centered all his attention upon the highest problems of the human intellect, and was at a loss to conceive how any one could spend his life in trifling pursuits or in the study of philology, mathematics, theoretical medicine, or law, instead of directing his mind to the holiest task of life. This task, according to the view of Ibn-Daud, consists in philosophical study, because its object is the knowledge of God, and herein lies man's superiority over the world of created things. He emphasized this point strongly in opposition to a certain class of his co-religionists in Spain who had a positive dislike for philosophy. Ibn-Daud was well acquainted with the reason for their mistrust of independent research. "There are many in our time," he remarked, "who have dabbled a little in science, and who are not able to hold both lights, the light of belief in their right hand and the light of knowledge in their left. Since in such men the light of investigation has extinguished the light of belief, the multitude think it dangerous, and shrink from it. In Judaism, however, knowledge is a duty, and it is wrong to reject it."