Postmodernism challenges traditional boundaries and rules through unexpected combinations and irony. It rejects distinctions between high and low art forms, emphasizes pastiche and intertextuality, and is playful. The term "Postmodern" was first used in the 1870s to describe a style of painting, and later applied to culture, music, architecture, society, law, literature and film. Influential postmodernist philosophers include Martin Heidegger, Jacques Derrida, Michel Foucault, Jean-François Lyotard, Fredric Jameson, and Douglas Kellner.