Introduction

Siger of Brabant (c. 1240-c. 1284) is one of the most controversial authors of the Middle Ages, and there are conflicting opinions about him. On one hand, some see him as the symbol of a dangerous heresy at the University of Paris. Siger of Brabant, along with Boethius of Dacia, is seen as the figurehead of a movement that sees philosophy as self-sufficient, detached from theology, and hence as the spokesman of disbelief in the Middle Ages. Since the studies of Ernest Renan in the nineteenth century, he is associated with the movement called ‘‘Latin Averroism,’’ which comes from the name of the Muslim philosopher Ibn Rushd known in the Latin West under the name ‘‘Averroes.’’ Siger is criticized for having supported three theses opposing Christian faith. Firstly, that there exists only one intellect unique to all humans, thus destroying any belief in the immortality of the soul and all personal judgments after death; secondly, that the universe has no beginning, which destroys the belief that the world was created by God; and thirdly, that human freedom exists in name only.

There seems to be good reason for these charges against Siger of Brabant. He was summoned to appear before the Inquisitor of France, Simon du Val, on January 18, 1277. Some think he would have fled from Paris to plead his case directly to the Pope in Orvieto. However, in 1284, he fell into disfavor, and was murdered by his secretary who had gone mad. The great Parisian condemnation of March 7, 1277, the most important intellectual censorship of the Middle Ages, was largely directed against him. He was considered to be an antiChristian thinker, and a scandal amongst his contemporaries. He angered the Bishop of Paris, Etienne Tempier. From 1268, Bonaventure vehemently criticized the theories of Siger in several of his university sermons, and in 1270, Thomas Aquinas wrote the well-argued work De unitate intellectus to take apart the interpretation that Siger gave Aristotle.

On the other hand, Dante Alighieri did not hesitate to reserve a place in paradise for him. He placed him alongside Peter Lombard, King Solomon, and Dionysius the Areopagite, but especially together with Albert the Great and Thomas Aquinas, who presents him with the highest praise: ‘‘It is Siger’s eternal light, in teaching at the Rue du Fouarre, that by demonstrating truths created hate and envy’’ (Dante, Par. X, 136-138). Siger is thus presented as one of the most remarkable philosophers of the thirteenth century, and as one of the most ‘‘excellent doctors of philosophy.’’ But who was really this ‘‘Sigerus magnus’’ mentioned in several manuscripts?