Of Siger's life, we know very few facts for certain. His exact place of birth remains unknown, as well as the locale and circumstances of his death. (Did he die peacefully in Liege, Belgium, or was he assassinated in Italy at the Roman curia?) Even the chronology of his works is uncertain. Although they are thought to have been written between 1265 and 1277, the precise dates remain conjectural.

Concerning his university career, facts are again unclear. Although it is certain that he never left the faculty of arts for one of the higher faculties (theology, medicine, law), his role in the debates that shook the University of Paris and led to the statutes of 1272 remains the subject of discussion (Putallaz and Imbach 1997 versus Bianchi 1999). At the beginning of his career, he was one of Thomas Aquinas's most outspoken adversaries...