First edition. Lucien Lévy-Bruhl (1857-1939), a member of the Institute and professor at the Sorbonne, was a leading French philosopher and sociologist. His work La Mentalité Primitive (Primitive Mentality) is a major text in early 20th-century anthropology and ethnology. In it, he theorizes the existence of a "pre-logical" or "pre-rational" thought process among so-called "primitive" peoples, an idea that would later be widely criticized.