The Arabians, moreover, made a point for the most part of studying the writings of Aristotle very diligently, and of availing themselves more especially both of his metaphysical and logical writings, and also of his _Physics_; they occupied themselves particularly with multiplying commentaries on Aristotle, and developing still further the abstract logical element there present. Many of these commentaries are still extant. Works of this kind are known in the West, and have been even translated into Latin and printed; but much good is not to be got from them. The Arabians developed the metaphysics of the understanding and a formal logic. Some of the famous Arabians lived as early as the eighth and ninth centuries; their progress was therefore very rapid, for the West had as yet made very little advance in culture. Alkendi, who wrote a commentary on the _Logic_, flourished in and about A.D. 800, under Almamun.[7] Alfarabi died in 966; he wrote commentaries on Aristotle’s _Organon_, which were made diligent use of by the Scholastics, and was also author of a work “On the Origin and Division of the Sciences.” It is related of him that he read through Aristotle’s treatise _On Hearing_ forty times, and his _Rhetoric_ two hundred times, without getting at all tired of them;[8] he must have had a good stomach. The very physicians made a study of philosophy, and formulated theories; among them was Avicenna (_b._ A.D. 984, _d._ A.D. 1064), who belonged to Bokhara, to the east of the Caspian Sea; he wrote a commentary on Aristotle.[9] Algazel (_d._ A.D. 1127 at Bagdad) wrote compendiums of logic and metaphysics; he was a sceptic of great ability, with a powerful mind of the Oriental cast; he held the words of the Prophet to be pure truth, and wrote _Destructio Philosophorum_.[10] Tofail died in Seville in A.D. 1193.[11] Averroës, who died A.D. 1217, was specially distinguished as the commentator of Aristotle.[12] The acquaintance of the Arabians with Aristotle has this interest in history that it was thus that Aristotle first became known also in the West. The commentaries on Aristotle and the collections of passages from his writings become thus for the Western world a fountain of philosophy. Western nations long knew nothing of Aristotle, excepting through such retranslations of his works and translations of Arabian commentaries on them. For such translations were made from Arabic into Latin by Spanish Arabs, and especially by Jews in the south of Spain and Portugal and in Africa; there was often even a Hebrew translation between. C. JEWISH PHILOSOPHERS.