Ludwik Fleck

Ludwik Fleck (Polish: [ˈludvik ˈflɛk]; Hebrew: לודוויק פלק; 11 July 1896 – 5 June 1961) was a Polish and Israeli physician and biologist who did important work in epidemic typhus in Lwów, Poland, with Rudolf Weigl and in the 1930s developed the concepts of "Denkstil" ("thought style") and "Denkkollektiv" ("thought collective"). Fleck's concept of "thought collective" is important in the philosophy of science and in logology (the "science of science"), helping explain how scientific ideas change over time, much as in Thomas Kuhn's later notion of "paradigm shift" (on Fleck's possible influence on Kuhn, see Jarnicki and Greif) and in Michel Foucault's concept of "episteme". Fleck's account of the development of facts at the intersection of active elements of a thought collective and the passive resistances of nature provides a way of considering the culture of modern science as evolutionary and evidence-oriented.