The coexistence of three religions in Andalusia--the Christian, the Mohammedan, the Mosaic--had given opportunity for the development of Averroism or philosophical Arabism. This was a repetition of what had occurred at Rome, when the gods of all the conquered countries were confronted in that capital, and universal disbelief in them all ensued. Averroes himself was accused of having been first a Mussulman, then a Christian, then a Jew, and finally a misbeliever. It was affirmed that he was the author of the mysterious book "De Tribus Impostoribus." In the middle ages there were two celebrated heretical books, "The Everlasting Gospel," and the "De Tribus Impostoribus." The latter was variously imputed to Pope Gerbert, to Frederick II., and to Averroes. In their unrelenting hatred the Dominicans fastened all the blasphemies current in those times on Averroes; they never tired of recalling the celebrated and outrageous one respecting the eucharist. His writings had first been generally made known to Christian Europe by the translation of Michael Scot in the beginning of the thirteenth century, but long before his time the literature of the West, like that of Asia, was full of these ideas. We have seen how broadly they were set forth by Erigena. The Arabians, from their first cultivation of philosophy, had been infected by them; they were current in all the colleges of the three khalifates. Considered not as a mode of thought, that will spontaneously occur to all men at a certain stage of intellectual development, but as having originated with Aristotle, they continually found favor with men of the highest culture. We see them in Robert Grostete, in Roger Bacon, and eventually in Spinoza. Averroes was not their inventor, he merely gave them clearness and expression. Among the Jews of the thirteenth century, he had completely supplanted his imputed master. Aristotle had passed away from their eyes; his great commentator, Averroes, stood in his place. So numerous were the converts to the doctrine of emanation in Christendom, that Pope Alexander IV. (1255) found it necessary to interfere. By his order, Albertus Magnus composed a work against the "Unity of the Intellect." Treating of the origin and nature of the soul, he attempted to prove that the theory of "a separate intellect, enlightening man by irradiation anterior to the individual and surviving the individual, is a detestable error." But the most illustrious antagonist of the great commentator was St. Thomas Aquinas, the destroyer of all such heresies as the unity of the intellect, the denial of Providence, the impossibility of creation; the victories of "the Angelic Doctor" were celebrated not only in the disputations of the Dominicans, but also in the works of art of the painters of Florence and Pisa. The indignation of that saint knew no bounds when Christians became the disciples of an infidel, who was worse than a Mohammedan. The wrath of the Dominicans, the order to which St.