Post-structuralism is not a single entity, but a loose collection of assumptions, concepts and perspectives which focus on three key themes: language and discourse; power and ideology; conflict and resistance. Although it is often described as developing in France in the 1960s, principally with the work of Barthes, Derrida, Foucault and Lacan, its roots are really in Marx and neoMarxists such as Gramsci, Adorno and Althusser. Far from being superseded by postmodernism, post-structuralism is currently being further developed by the work of Giddens, Bourdieu, Billig, Laclau, Rorty and Fairclough in a range which extends from the broadest of social theory through a reconstruction of political economy to critical discourse analysis.