Additional Sources
19 - Karl Popper

Most Important Work
The Open Society and Its Enemies, Vol.1: The Spell of Plato (1945)
The Open Society and Its Enemies, Vol.2: The High Tide of Prophecy: Hegel, Marx, and the Aftermath (1945)
More about...
- Initially Karl Popper was a Viennese Epistemologist; his most well-known book being The Logic of Scientific Discovery (1934). His approach was called Critical Rationalism. Scientific progress can not be advanced by empirical “proofs”, he argued, but by an open process of criticism of rather hypothetical theories.
- Fleeing from the Nazis to New Zealand, he wrote, what he called his “war effort”: The two volumes of The Open Society (1945). His epistemological position turned into political philosophy. In the book he criticized those thinkers, who had laid the intellectual foundations of totalitarian despotism – from Plato to Marx. Utopian planning of a society would inevitably lead to overreach, misery and dictatorship. Societal progress can only take place where open criticism is allowed, and where problems were solved step by step by reforms.
- In the 1960s Popper often clashed with prophets of the new left (like Theodor Adorno), who he regarded as somewhat totalitarian.
Fun Fact
Because Popper was a quite undogmatic liberal thinker, even moderate/anti-totalitarian social democrats seemed to admire him, former German chancellor Helmut Schmidt being the most notable example.
Additional Resources
Stanford Encyclopedia of Philosophy: Karl Popper
https://plato.stanford.edu/entries/popper/