Petrus Johannis Olivi (c. 1248–1298) is today considered one of the most important intellectuals of the second half of the 13th century. Although he died at a young age, he left behind an impressive philosophical and theological work which was placed under the censure of the Church various times. The contributions in this volume (in French and Italian) reveal a broad spectrum of Olivi's different scholarly methods, demonstrating his intellectual activity and presenting some of his most original philosophical theories.