Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian-British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the classical inductivist views on the scientific method in favor of empirical falsification. According to Popper, a theory in the empirical sciences can never be proven, but it can be falsified, meaning that it can (and should) be scrutinized with decisive experiments. Popper was opposed to the classical justificationist account of knowledge, which he replaced with critical rationalism, namely "the first non-justificational philosophy of criticism in the history of philosophy".

In political discourse, he is known for his vigorous defence of liberal democracy and the principles of social criticism that he believed made a flourishing open society possible. His political philosophy embraced ideas from major democratic political ideologies, including libertarianism/classical liberalism, socialism/social democracy and conservatism, and attempted to reconcile them.

Karl Popper