In one of his last writings, Life: Experience and Science, Michel Foucault argued that twentieth-century French philosophy could be read as dividing itself into two divergent lines: on the one hand, we have a philosophical stream which takes individual experience as its point of departure, conceiving it as irreducible to science. On the other hand, we have an analysis of knowledge which takes into account the concrete productions of the mind, as are found in science and human practices. In order (...) to account for this division, Foucault opposed epistemologists such as Cavaillès and Canguilhem to phenomenologists such as Merleau-Ponty and Sartre but, also, and more particularly, he opposed Poincaré to Bergson. The latter was presented by Foucault as being the key-figure of the ?philosophy of experience? at the beginning of the twentieth century. Fifteen years later, in his Deleuze and in the Logics of Worlds, Alain Badiou again uses this dual structure in his interpretation of the past hundred years of French thought. He employs a series of oppositional couples: himself and Deleuze, Lautmann and Sartre, and, finally, Brunschvicg and Bergson. On the one hand a ?mathematical Platonism? and on the other a ?philosophy of vital interiority.? This Manichean reading of philosophy, and the strategic use of the figure of Bergson has, itself, a long tradition. It was also proposed by Althusser who, following Bachelard, opposed his standpoint to any form of ?empiricism.? Althusser developed his thought from a tradition of Marxist thinkers and ideologists, which included Politzer's and Nizan's critique of bourgeois philosophy and, even before that, neo-Kantians such as the philosophers of the Revue de métaphysique et de morale. The aim of this essay is to deconstruct and to put into its precise context of production this series of genealogies which entails the mobilization of Bergsonism and of the name ?Bergson.? By doing so, I hope to weight the importance of Bergsonism in twentieth-century French philosophy, in both its ?positive? and its ?negative? aspect. The essay will proceed regressively, taking into account figures such as Althusser, Badiou, Deleuze, Foucault, Canguilhem, Cavaillès, Sartre, Merleau-Ponty, but also Polizer, Brunschvicg and Alain. The conclusion of the essay is an attempt at reading the ?Bergson renaissance? in the light of new discoveries in genetics and the cognitive sciences and to tie it to the renewal of studies in the history of French philosophy. (shrink)