Karl Popper

Karl Popper, an eminent philosopher and social theorist, was born in Vienna, but subsequently became a British subject. When young, Popper was intellectually precocious and had a keen interest in science, psychology, and, subsequently, philosophy ... Popper also is well known for his writings on social philosophy. His books Open Society and Its Enemies and The Poverty of Historicism, both written during the Second World War, were powerful attacks on Plato, Marx, and their arguments in favor of historical inevitability as enemies of an open society.

Internationally-acclaimed philosopher Karl R. Popper confided to Hayek, "I think that I have learned more from you than from any other living thinker ..." ... Hayek had ... Popper speak at a seminar, and Popper expanded it into his most controversial book, The Open Society and Its Enemies (1945), a passionate attack on Plato and Karl Marx; Hayek helped find a publisher and persuaded colleagues at the London School of Economics to give Popper a teaching position — rescuing him from a hostile academic environment in New Zealand. Through the ups and downs of Hayek's life, Popper remained his closest friend.

That spirit [of humility] is also the spirit of modern science, but it was not always this way. In the Novum Organum, written in 1620, Francis Bacon defined empirical inquiry as an effort 'to seek, not pretty and probable conjectures, but certain and demonstrable knowledge.' ... Modern science takes a different view. In the words of Karl Popper (1969: 115), 'Scientific theories ... are genuine conjectures—highly informative guesses about the world which although not verifiable (i.e., capable of being shown to be true) can be submitted to severe critical tests.'

JS: Many libertarians know Karl Popper for his book The Open Society and Its Enemies, and you discuss some of Popper's ideas about scientific method in Invariances.
RN: The book contains ... a new argument against his anti-inductivism. Popper is famous for saying that induction can't be justified, that the only inferences that data support are to deductive consequences of the data ...
Popper's anti-inductive conclusions were always held to be counterintuitive, even ridiculous, but he swallowed them, and so did his followers. Now I'm saying something stronger than has been said thus far, namely, that their view is incoherent.