Revisiting the Pouchet-Pasteur controversy over spontaneous generation: understanding experimental method

Louis Pasteur's defeat of belief in spontaneous generation has been a classical rationalist example of how the experimental approach of modern science can reveal superstition. Farley and Geison (Bull Hist Med 48:161-198, 1974) told a counter-story of how Pasteur's success was due to political and ideological support rather than superior experimental science. They claimed that Pasteur violated proper norms of scientific method, and that the French Academy of Science did not see this, or did not want to. Farley and Geison argued that Pouchet's experiments were as valid as those of Pasteur. In this paper I argue that the core of the scientific debate was not general theories for or against spontaneous generation but the outcome of specific experiments. It was on the conduct of these experiments that the Academy made judgements favorable to Pasteur. Claude Bernard was a colleague of Pasteur, supportive and sometimes critical. I argue that Bernard's fact-oriented methodology of "experimental medicine" is a better guide to explaining the controversy than the hypothetic-deductive view of scientific method typical of logical empiricism.