While the minds of the three great religious communities were thus distracted, some rays of Mohammedan learning penetrated into the Christian schools. A few travelers had brought back specimens from the East. The Crusades still further stimulated intercourse between the hostile creeds. Arabic versions of Aristotle were imported along with bales of merchandise into Sicily, Italy, and the south of France; and some diligent scholars translated the Arabic works of science into Latin. Raymond, Bishop of Toledo (1130-1150), caused several of the works of Avicenna, Gazali, and Alfarabi to be translated into Latin; and Michael Scot and others translated the Arabic versions of Greek works into Latin. All this mass of new literature gave an immense stimulus to metaphysical controversy. The intoxication of mind produced a flood of discussion which threatened to be fatal to orthodoxy. The first scholastics professed themselves devout sons of the Church, but the inevitable tendency of free inquiry was to lead them further and further away from orthodoxy. The doctrines of Avicenna, Averroes, and Avicebron convulsed the Christian schools; and the teaching of Aristotle seemed to lead to the plainest pantheism and materialism.
The Catholic Church was now thoroughly aroused and alarmed. It was, indeed, shaken to its foundations; and, as Aristotle seemed the original source of all these heresies, he was formally condemned by the Church in 1204, 1209, and 1215. Thus in all the three religious communities the appeal to reason was dangerous to faith; and the Aristotelian philosophy was a terror equally to orthodox Jews, to orthodox Mohammedans, and to orthodox Catholics.
The Catholic Church seemed on the very brink of destruction; the scandalous lives and the venality of the court of Rome shocked all Christendom. Every country swarmed with heretics in revolt against the tyranny of the priesthood. But the Pontiff was equal to the crisis. The Crusades had familiarized the followers of the meek and gentle Jesus with the idea that the slaughter of infidels was grateful to the Creator. And heretics were worse than infidels. Accordingly, Innocent III carried fire and sword into the fairest provinces of Christendom.
A great revolution was at hand, and the Church was saved in the very crisis of her existence. In the same year, 1206, Dominic, a Spaniard, founded an order of mendicant friars at Toulouse, and Francis, at Assisi. They were bound to devote themselves to poverty and preaching. The new orders spread with marvelous rapidity, and in a very few years all Europe was filled with them. They were devoted to the defense of Catholic dogma. Each order cultivated the most profound learning, and studied the pagan philosophers to profit by them and to confute them. The rival fraternities vied with each other in celebrated names. The Franciscans boasted Alexander de Hales; the Dominicans, Albert of Cologne, surnamed the Great.