 This led Bergson to discuss the 'Body' and 'Self' in detail, arguably prompting the fundamental ontological and epistemological questions to be raised later in the 20th century.Bergson's work was a major influence on Gilles Deleuze, who wrote a monograph on him ("Bergsonism") and whose philosophical analyses of cinema ("" and "") develop his ideas.Following debates concerning the foundation of mathematics around the mathematician and philosopher Henri Poincaré (1854–1912), who opposed Bertrand Russell and Frege, various French philosophers started working on philosophy of science, among them Gaston Bachelard, who developed a discontinuous view of scientific progress, Jean Cavaillès (1903–1944), Jules Vuillemin (1920-2001), or Georges Canguilhem, who would be a strong influence of Michel Foucault ; in his introduction to Canguilhem's "The Normal and the Pathological", Foucault wrote