By the great thinkers of the thirteenth century, Averroes, though regarded as heretical and dangerous in religion, was looked up to as an able thinker, and the commentator par excellence; so much so that St. Thomas borrowed from him the very form of his own Commentaries, and Dante assigned him a distinguished place, beside Plato and Aristotle, in the limbo of ancient sages (’Inferno,’ iv. 143).  But in the following century—­mainly, no doubt, because he was chosen as the patron of certain strongly heretical movements, such as those instigated by the arch-rationalist Frederic II—­he came to be regarded as the precursor of Antichrist, if not that personage himself:  being credited with the awful blasphemy of having spoken of the founders of the three current religions—­Moses, Jesus, and Muhammad—­as “the three impostors.”  Whatever truth there may be in this, so much is certain, that infidelity, in the sense of an utter disbelief in Christianity as a revealed religion, or in any sense specially true, dates from the thirteenth century, and is due in large measure to the influence of Averroes.  Yet he was a great favorite with the Franciscans, and for a time exercised a profound influence on the universities of Paris and Oxford, finding a strong admirer even in Roger Bacon.  His thought was also a powerful element in the mysticism of Meister Eckhart and his followers; a mysticism which incurred the censure of the Church.

Thus both the leading forms of heresy which characterized the thirteenth century—­naturalism with its tendency to magic, astrology, alchemy, etc., etc., and mysticism with its dreams of beatific visions, its self-torture and its lawlessness (see Goerres, ’Die Christliche Mystik’)—­were due largely to Averroes.  In spite of this, his commentaries on Aristotle maintained their credit, their influence being greatest in the fourteenth century, when his doctrines were openly professed.  After the invention of printing, they appeared in numberless editions,—­several times in connection with the text of Aristotle.  As the age of the Renaissance and of Protestantism approached, they gradually lost their prestige.  The chief humanists, like Petrarch, as well as the chief reformers, were bitterly hostile to them.  Nevertheless, they contributed important elements to both movements.

Averroism survived longest in Northern Italy, especially in the University of Padua, where it was professed until the seventeenth century, and where, as a doctrine hostile to supernaturalism, it paved the way for the study of nature and the rise of modern science.  Thus Averroes may fairly be said to have had a share in every movement toward freedom, wise and unwise, for the last seven hundred years.  In truth, free thought in Europe owes more to him than to any other man except Abelard.  His last declared follower was the impetuous Lucilio Vanini, who was burned for atheism at Toulouse in 1619.

The best work on Averroes is Renan’s ‘Averroes et l’Averroisme’ (fourth edition, Paris, 1893).  This contains, on pages 58-79, a complete list both of his commentaries and his original writings.