20th-century French philosophy is a strand of contemporary philosophy generally associated with post-World War II French thinkers, although it is directly influenced by previous philosophical movements. Bergson The work of Henri Bergson (1859–1941) is often considered the division point between nineteenth- and twentieth-century French philosophy. Essentially, despite his respect for mathematics and science, he pioneered the French movement of scepticism towards the use of scientific methods to understand human nature and metaphysical reality. Positivism, which, for instance, the French sociologist Durkheim was interested in at the time, was not appropriate, he argued. Unlike later philosophers, Bergson was highly influenced by biology, particularly Darwin's Origin of Species, which was published in the year Bergson was born. 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 (Cinema 1: The Movement Image and Cinema 2: The Time-Image) develop his ideas. Philosophy of science 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: Take away Canguilhem and you will no longer understand much about Althusser, Althusserism and a whole series of discussions which have taken place among French Marxists; you will no longer grasp what is specific to sociologists such as Bourdieu, Robert Castel, Jean-Claude Passeron and what marks them so strongly within sociology; you will miss an entire aspect of the theoretical work done by psychoanalysts, particularly by the followers of Lacan. Further, in the entire discussion of ideas which preceded or followed the movement of '68, it is easy to find the place of those who, from near or from afar, had been trained by Canguilhem. Starting in the 1980s, Bruno Latour (b. 1947), teacher at the engineering school École nationale supérieure des mines de Paris, would develop the actor-network theory, a distinctive approach to social theory and research, best known for its controversial insistence on the agency