Karl Popper said no scientific theory can be proven, only tested
Karl Popper argued that science does not advance by piling up confirmations. A theory can never be proved true, but a decisive experiment can show it false, and a claim that could never be refuted is not science at all. That test of falsifiability became one of the most influential ideas in 20th-century philosophy.
Popper was born in Vienna in 1902 to an assimilated Jewish family that had converted to Lutheranism. His father, a lawyer, kept a library of 12,000 to 14,000 books, and Popper later called his childhood decidedly bookish. At 17 he was briefly drawn to Marxism, but after police shot eight unarmed comrades in a street clash in June 1919, he turned against historical materialism and stayed a social liberal for life.
His path was unusual. He tried road building but found the labour too heavy, qualified as a journeyman cabinetmaker while dreaming of running a daycare centre, volunteered at one of Alfred Adler's children's clinics, and trained as a primary teacher. He earned a psychology doctorate in 1928 and taught secondary maths and physics.
Fearing Nazism, he wrote at night to produce a book that might win him an academic post somewhere safe for people of Jewish descent. The result, The Logic of Scientific Discovery, appeared in 1934, attacking inductivism and logical positivism and proposing falsifiability as the line between science and non-science. In 1937 he secured a lectureship in Christchurch, New Zealand, where he wrote The Open Society and Its Enemies, a defence of liberal democracy against totalitarian and historicist thinking.
From 1946 he was at the London School of Economics, where he founded the philosophy department, and in the 1960s he clashed with Adorno and Habermas over how the social sciences should work. He and his wife Hennie chose not to have children because of the war, a decision he called perhaps cowardly but in a way right. He was knighted, won the Kyoto Prize in 1992, and kept working until shortly before his death in 1994.
Source: Karl Popper
