_Introduced into Rome._--For a time the original works of Aristotle were lost. They lay buried in an obscure retreat whither they had been carried for safe preservation, and no one knew what they were. Sylla, capturing the city, brought them to Rome, where they were discovered to be the works of the great master, and Cicero gives them, with some labor and learning, to the public. But the Roman mind never mastered the logic of Aristotle. In all Roman philosophy, says St. Hilaire, there is scarcely a logician worthy of the name. For several centuries, if not in Rome, yet in Alexandria and Athens, in Greece and in Egypt, the logic of Aristotle continued to be assiduously cultivated. _Logic in the Middle Ages._--It was in the middle ages, however, that logic received its chief cultivation and its highest honors. Aristotle was for some six centuries almost the only teacher of the human mind, and the Organon was the foundation of his knowledge. Nor during the irruption of the northern hordes, and the revolutions of society, and empire, and human manners, which followed, did the philosophy and logic of Aristotle pass out of sight or out of mind. It seemed impossible for any revolution of empire or of time to shake its foundations or break its sceptre over the human mind. In the seventh century, Isidore of Seville, and Bede the Venerable, gave it their labors and renown. In the eighth, Alcuin introduced it into the court of Charlemagne. In the twelfth, Abelard, and the controversy between the Realists and Nominalists, gave this science still more importance. _Logic in the Arabian Schools._--Meanwhile, the Mohammedans had been in advance of the Christians in the study of this science. The Arabs had inherited the learning of antiquity, and had carried the cultivation of the peripatetic philosophy to a high degree of perfection more than a century before it had received the homage of the West. From Arabia it passed, with the march of conquest, into Spain, and some of the ablest commentators Europe has produced, on the works of Aristotle, have been the Moors of Spain. _Continuance of Aristotle's Dominion._--The Crusades tended only to enlarge the sphere of this influence. Such men as Albert the Great, and Thomas Aquinas, became, in the thirteenth century, expounders of Aristotle. Not till the sixteenth century did this long dominion over the human mind show symptoms of decadence. _The Reformers._--Luther, among the Protestant reformers, sought to banish logic from the schools; but it was retained, and in the Protestant universities was still professed.