His contemporary Ibn Sina (d. 428), for us Avicenna, was of a different nature, and his lines were cast in different places. He was a wanderer through the courts of northern Persia. The orthodox and stringent Mahmud he carefully avoided; the Buwayhids and those of their ilk took such heresies as his more easily. Endowed with a gigantic memory and an insatiable intellectual appetite, he was the encyclopædist of his age, and his scientific work, and especially that in medicine, went further than anything else to put the Muslim East and mediæval Europe in the strait waistcoat from which the first has not yet emerged and the second only shook itself free in the seventeenth century. He was a student of Aristotle and a mystic, as all Muslim students of Aristotle have been. How far his mysticism enabled him to square the Qur’an with his philosophy is not clear; such men seldom said exactly what they meant and all that they thought. He was also a diligent student and reader of the Qur’an and faithful in his public religious duties. Yet the Muslim world asserts that he left behind him a testamentary tractate (_wasiya_) defending dissimulation as to the religion of the country in which we might be; that it was not wrong for the philosopher to go through religious rites which for him had no meaning. He, too, is significant for his time, and, if our interest were philosophy, would call for lengthened treatment. As it is, he marks for us the accomplished separation between students of theology and students of philosophy. An equally well known and by us much better loved name is that of Umar al-Khayyam, who died later, about 515, but who may fitly be grouped with Ibn Sina. He, too, was a _bon vivant_, but of a deeper, more melancholy strain. His wine meant more than friendly cups; it was a way of escape from the world and its burden. His science, too, went deeper. He was not a gatherer and arranger of the wisdom of the past; his reformed calendar is more perfect than that which we even now use. His faith is a riddle to us, as it was to his comrades. But it was because he had no certain truth to proclaim that Umar did not speak out clearly. His last words were almost those of Rabelais, “I go to meet the great Perhaps.” Anecdotage connects his name with that of al-Ghazzali. Neither had escaped the pall of universal scepticism which must have descended upon their time. But al-Ghazzali, by God’s grace, as he himself reverently says, was enabled to escape. Umar died under it. [Sidenote: ABU-L-ALA AL-MA‘ARRI]