"Sir Karl Raimund Popper" was an Austrian-British philosopher and professor. He is generally regarded as one of the greatest philosophy of science/philosophers of science of the 20th century.
Popper is known for his rejection of the classical Inductivism/inductivist views on the scientific method, in favour of Falsifiability/empirical falsification: A theory in the empirical sciences can never be proven, but it can be falsified, meaning that it can and should be scrutinised by decisive experiments. If the outcome of an experiment contradicts the theory, one should refrain from ad hoc manoeuvres that evade the contradiction merely by making it less falsifiable. Popper is also known for his opposition to the classical justificationism/justificationist account of knowledge which he replaced with critical rationalism, "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 came to believe made a flourishing "open society" possible. His political philosophy embraces ideas from all major democratic political ideologies and attempts to reconcile them: social democracy, classical liberalism and conservatism, more explicitly so in his later years.If you enjoy these quotes, be sure to check out other famous philosophers! More Karl Popper on Wikipedia.