The wine, instead of mixing with the water as we should expect, changes places with it, each liquid remaining pure. This passage has caused a certain stir in the scholarly literature. Alexander Koyré, the great historian of science, best known for his work on cosmology, considered the story as a reliance on untested thought-experiments gone too far: 'Galileo. . . had never made the experiment; but, having heard of it, reconstructed it in his imagination, accepting the complete and essential incompatibility of water with wine as an indubitable fact'. So much for casting off authority and beginning afresh from sense experience! Koyré, however, does not name a source.