Postmodernism rejects the idea of a single rationality or objective reality. Jacques Derrida developed concepts like deconstruction and logocentrism to critique foundations of knowledge. Jean Baudrillard argued that contemporary society has moved beyond production and Marxism into a phase dominated by consumerism, media, and information. He believed these forces create a hyperreality that replaces reality. Postmodernists challenged concepts of truth and objective knowledge.