them to be made harmless—and then slew the magician; so that to this day the water is safe. Stories of this sort are interwoven with admirably intelligent accounts of these distant countries. All are equally credited and credible.
What strikes a modern reader with astonishment is by no means the ignorance of the writer, but rather his entire lack of the critical faculty. This lack, for Europeans as well as for Arabs, may be taken as characteristic of the middle ages. Our ancestors appear, at times, nothing but adventurous Eskimo who had read Aristotle.
The reign of Faith appears, at first glance, so absolute during the Middle Ages, that one is tempted to believe that for a thousand years no voice was lifted against established religion. A study of the details of history brings, however, many episodes to light that exhibit something like a continuous change from the rationalism of the ancients to that of the moderns. The chain is easiest to trace, of course, in the history of philosophy. It existed likewise in the history of science. The whole of the thirteenth century, exclusively religious as it appears at first sight, was stirred by an undercurrent of free inquiry which has left little trace in written history solely because the history of that period was written by the Dominican school. Roger Bacon was a product of his age, then, not a lusus naturæ.
The philosophy of the Arab commentators of Aristotle—pantheistic in its essence—was utterly opposed to the philosophy of orthodox scholastics. In the year 1209 the council of Paris condemned the Natural Philosophy of Aristotle and its commentaries. A bull of Gregory IX. in 1231 confirmed the condemnation. Such condemnations demonstrated the prevalence of presumed error. By the middle of the century Albertus Magnus had arranged Aristotelian teachings so that they were again in favor, and he incorporated in his text, from the Arabs, all that was useful to his argument. Heterodox comments were refuted when they were not rejected outright. St. Thomas Aquinas gave an even more solid form to orthodox philosophy and waged persistent war on the specific doctrines of the Arabs. In the year 1277 a series of thirteen propositions, mostly taken from Avicenna and Averroës, was formally condemned at Paris and at Oxford. In the general chapter of the Franciscans held at Assisi in 1295, an especial warning was given against 'exotic' opinions. These instances from the history of a single century indicate that there was no universal stagnation. Condemnations of heterodox philosophizing were required
