12 questions · Philosophy
Karl Popper, born in Vienna in 1902, grew up in the intellectual climate of the Danube metropolis, worked as a young man as a cabinetmaker's apprentice, social worker and teacher and wrestled all the while with a question that never let him go: what distinguishes real science from mere pseudoscience? Marxism and psychoanalysis, he observed, could seemingly explain everything and precisely that made him suspicious. Einstein's relativity, by contrast, dared predictions on which it could fail. From this came his famous answer: a theory is scientific not if it can be confirmed, but if it can be refuted: the criterion of falsifiability, developed in 'The Logic of Scientific Discovery' (1934). No number of white swans proves that all swans are white; a single black one refutes it. Science grows through bold conjectures and severe refutations: 'critical rationalism' is the name of Popper's programme. Fleeing National Socialism (doubly threatened as a Viennese of Jewish descent) Popper emigrated to New Zealand in 1937. There he wrote his 'war effort': 'The Open Society and Its Enemies' (1945), a passionate defence of democracy and a reckoning with the totalitarian traditions of thought he traced back to Plato, Hegel and Marx. Its core idea: the question is not 'Who should rule?' but: how do we get rid of bad rulers without bloodshed? Instead of grand utopias he recommended piecemeal reforms whose errors remain correctable. From 1946 Popper taught at the London School of Economics; in 1965 he was knighted. Famous too is his 'paradox of tolerance': unlimited tolerance towards the intolerant destroys tolerance itself. Did you know that a quarrel with Wittgenstein in Cambridge in 1946 entered the history of philosophy as the 'poker incident'? Popper died near London in 1994, aged 92.
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falsifiability
A theory is scientific if it can be refuted: not if it can merely be confirmed.
💡 Did you know? A theory is scientific only if it can in principle be refuted: Popper's famous criterion of demarcation.
the black swan
No number of white swans proves that all are white: a single black one refutes it.
💡 Did you know? No number of white swans proves „all swans are white“: a single black one refutes it. Thus Popper shows the weakness of induction.
critical rationalism
Knowledge grows through bold conjectures and severe attempts at refutation: certainty does not exist.
💡 Did you know? Popper's „critical rationalism“ relies on constant testing and refuting rather than final certainties.
The Logic of Scientific Discovery
There he develops the falsifiability criterion: against the verificationism of the Vienna Circle.
💡 Did you know? With „The Logic of Scientific Discovery“ (1934) Popper revolutionised the philosophy of science.
The Open Society and Its Enemies
His 'war effort' from New Zealand exile: tracing totalitarian traditions back to Plato, Hegel and Marx.
💡 Did you know? „The Open Society and Its Enemies“, written in exile, defends democracy against totalitarian thinkers from Plato to Marx.
How do we get rid of bad rulers
For Popper, democracy is above all: change of power without violence.
💡 Did you know? Not „Who should rule?“ but „How do we get rid of bad rulers without bloodshed?“: Popper's central question of democracy.
tolerance of the intolerant destroys tolerance
From a footnote of 'The Open Society': cited to this day in debates on militant democracy.
💡 Did you know? His „paradox of tolerance“: unlimited tolerance, even of the intolerant, ultimately destroys tolerance itself.
New Zealand
Doubly threatened as a Viennese of Jewish descent: there he wrote 'The Open Society'.
💡 Did you know? Fleeing the Nazis, Popper, from a Jewish family, went all the way to New Zealand at the other end of the world.
London School of Economics
In 1965 he was knighted by the Queen: Sir Karl Popper.
💡 Did you know? After the war Popper taught at the London School of Economics and was knighted: „Sir Karl“.
piecemeal reforms
Small steps whose errors remain correctable: grand utopias, for Popper, end in violence.
💡 Did you know? Instead of utopian grand designs, Popper recommends cautious „piecemeal reforms“ that can be corrected if they fail.
the poker incident
In Cambridge, Wittgenstein reportedly gestured with a fireplace poker: what exactly happened remained forever disputed.
💡 Did you know? In 1946 Wittgenstein reputedly brandished a fireplace poker in anger during a debate with Popper: the legendary „poker affair“.
92
Born in Vienna in 1902, died near London in 1994: he worked to the very end.
💡 Did you know? Popper lived to 92 and remained, into old age, a combative defender of the open society.
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