(ca. 1240–ca. 1284). A member of the Picard “nation” at Paris, Siger was by 1266 a teaching master of arts in Paris and canon of Saint-Paul, Liège. He was a leading exponent of Aristotle, known largely through the works of Averroes. He and scholars of similar mind are known as “Latin Averroists.” As is usual for the 12th and 13th centuries, they knew Aristotle mostly through the interpretations of Averroes, Proclus, and particularly Avicenna. This tendency made Siger suspect, and in 1270 he was involved in bishop Étienne Tempier’s condemnation of thirteen theological errors at Paris. In the same year, Thomas Aquinas wrote De unitate intellectus contra Averroistas, directed chiefly against Siger and his followers.
The controversy continued until 1276, when Siger and two others were indicted for heresy by the French inquisitor Simon du Val, but Siger had already fled the country, apparently to make an appeal to the papal court. According to John Peckham, Siger was killed at Orvieto ca. 1284.
Siger was an Aristotelian in believing that Aristotle’s meaning should not be concealed, even if it conflicted with revealed truth. The two Aristotelian doctrines that caused constant consternation for philosopher-theologians at this time were the eternity of the world, which Aristotelians held to be true but theology knew to be false, and the unity of the intellect, which denied the possibility of the resurrection of the individual, since every mind was subsumed into one unified intellect after death. This did not endear Siger to many, although he himself believed that truth was always on the side of faith and that in cases of apparent conflict between faith and reason one should always decide for revelation rather than reason. Critics accused him of holding to “double truth,” that is, that some things were true in philosophy but false in theology. He himself may have felt as confusion and uncertainty that which outsiders took for lack of belief.
His main works are commentaries and questions on Aristotle, especially on the De anima, the Physics, and the Metaphysics, and shorter treatises on, for example, the eternity of the world.
