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Fleck, Ludwik

(1896–1961), microbiologist and pioneer in the sociology of knowledge. Born in Lwów, Ludwik Fleck graduated from Lwów University’s medical school in 1920, eventually specializing in microbiology. In 1923 he married Ernestina Waldman; they had one son, Ryszard (Arieh), born in 1924. After 1925, Fleck headed a bacteriological laboratory at Lwów General Hospital and served as director of a private medical laboratory.

While in the Lwów ghetto during World War II, Fleck developed a way to produce an antityphus vaccine from the urine of typhus patients. He was deported to Auschwitz in 1943 and then sent to Buchenwald, where he worked in a microbiology laboratory. Because of this assignment, he survived the camp and was able to save the lives of his wife and son. After more than a decade of activity as a distinguished microbiologist in Poland, in 1957 Fleck and his wife left for Israel to join their son. There, Fleck worked at the Institute for Biological Research at Nes Tsiyonah.

Fleck’s main claim to fame involved his pioneering contributions to the sociological study of science. Scientific research, he proposed, is above all a social and cultural phenomenon. His most important study, Entstehung und Entwicklung einer wissenschaftlichen Tatsache (Genesis and Development of a Scientific Fact; 1935), analyzed the origins of the Wassermann test for the detection of syphilis. This test, Fleck argued, was not the work of a solitary genius but reflected the coordinated efforts of thousands of researchers. The basic unit of production of scientific knowledge is a “thought collective”—a group of scientists that shares the same “thought style,” acquired during a long process of learning and socialization. Scientists perceive natural phenomena through the prism of the “thought style” of their community, that is, through a specific set of concepts and practices. “Scientific facts,” therefore, cannot be dissociated from the methods used to display them.

Fleck’s book was rediscovered in the 1970s as a result of increased interest in the sociology of scientific knowledge and the social and cultural history of science. Thomas Kuhn acknowledged him as a major influence. Fleck’s stature continued to grow in the 1980s and 1990s. Today his ideas are taught in many introductory courses in the history or sociology of science. Moreover, the official award of the Society for Social Studies of Science is called the Fleck Prize.

Suggested Reading

Robert S. Cohen and Thomas Schnelle, eds., Cognition and Fact: Materials on Ludwik Fleck (Dordrecht, Netherlands, and Boston, 1986); Ludwik Fleck, Genesis and Development of a Scientific Fact, trans. Fred Bradley and Thaddeus J. Trenn (Chicago and London, 1979).