Gaston Bachelard (; French: [baʃlaʁ]; 27 June 1884 – 16 October 1962) was a French philosopher. He made contributions in the fields of poetics and the philosophy of science. To the latter, he introduced the concepts of epistemological obstacle and epistemological break (obstacle épistémologique and rupture épistémologique). He influenced many subsequent French philosophers, among them Michel Foucault, Louis Althusser, Dominique Lecourt and Jacques Derrida, as well as the sociologists Pierre Bourdieu and Bruno Latour.
For Bachelard, the scientific object should be constructed and therefore different from the positivist sciences; in other words, information is in continuous construction. Empiricism and rationalism are not regarded as dualism or opposition but complementary, therefore studies of a priori and a posteriori, or in other words reason and dialectic, are part of scientific research.
