Karl Popper

Karl Popper was an Austrian-British philosopher of science and political philosophy who developed the criterion of falsifiability as the demarcation between science and non-science. His The Logic of Scientific Discovery argued that scientific theories cannot be verified by observation but only falsified — and that the willingness to be refuted is what distinguishes science from pseudoscience. His political philosophy, in The Open Society and Its Enemies, was a sustained critique of historicism and totalitarianism, defending democratic liberalism against Plato, Hegel, and Marx.