1. The Philosophy of Ibn Roshd, and his interpretation of Aristotle, have had extremely little effect upon the Muslim world. Many of his works, in the original, are lost, and we have them only in Hebrew and Latin translations. He had no disciples or followers. In retired corners no doubt many a free-thinker or Mystic might be met with, to whose mind it looked sufficiently fantastic to toil earnestly with philosophic questions of a theoretical kind; but Philosophy was not permitted to influence general culture or the condition of affairs. Before the victorious arms of the Christians the material civilization as well as the intellectual culture of the Muslims retreated farther and farther. Spain became like Africa, where the Berber was ruler. The times were serious: the very existence of Islam in these regions was at stake. Men made ready for fighting against the enemy, or even against one another; and pious brethren everywhere formed unions for mystic observances. In the Sufi orders of these people, a few philosophical formulae at least were still preserved in safety. When, towards the middle of the thirteenth century, the emperor Frederick II submitted a number of philosophical questions to the Muslim scholars of Ceuta, the Almohad Abdalwahid charged Ibn Sabin, founder of a Mystic order, to reply to them. He did so, drawling forth in a pedantic tone the views both of ancient and recent philosophers, and affording a glimpse of the Sufi secret,—that God is the reality of all things. The only thing, however, which we can learn from his answers, may be said to be, that Ibn Sabin had read books, of which he thought the Emperor Frederick had not the faintest notion. 2. In small State-systems, the Muslim civilization of the West drifted away, now rising, now falling. But before it vanished completely, a man appeared, who endeavoured to discover the law of its formation, and who thought to found therewith a new philosophical discipline,—the Philosophy of Society or of History. That remarkable man was Ibn Khaldûn, born at Tunis is the year 1332, of a family belonging to Seville. There he also received his upbringing, and there he was next instructed in philosophy, partly by a teacher who had been trained in the East. After studying all known sciences, he occupied himself sometimes in the service of the Government, and sometimes in travel, proving everywhere an excellent observer. He served various princes in the capacity of secretary, and he was ambassador at several courts in Spain and Africa: as such he visited the Christian court of Peter the Cruel in Seville. He was also at the court of Tamerlane in Damascus. He had thus acquired a wide and full experience of the world, when he died at Cairo in the year 1406. In character perhaps he does not take a high rank; but a measure of vanity, dilettantism and the like, may readily be forgiven to the man who, above all others in his time, lived for Science.