Siger of Brabant (c.1240–84), French philosopher, an activist in the philosophical and political struggles both within the arts faculty and between arts and theology at Paris during the 1260s and 1270s. He is usually regarded as a leader of a ‘radical Aristotelianism’ that owed much to Liber de causis, to Avicenna, and to Averroes. He taught that everything originates through a series of emanations from a first cause. The world and each species (including the human species) are eternal. Human beings share a single active intellect.
There is no good reason to think that Siger advanced the view that there was a double truth, one in theology and another in natural philosophy. It is difficult to distinguish Siger’s own views from those he attributes to ‘the Philosophers’ and thus to know the extent to which he held the heterodox views he taught as the best interpretation of the prescribed texts in the arts curriculum. In any case, Siger was summoned before the French Inquisition in 1276, but fled Paris. He was never convicted of heresy, but it seems that the condemnations at Paris in 1277 were partially directed at his teaching. He was stabbed to death by his clerk in Orvieto (then the papal seat) in 1284. C.G.Norm.