Although Ludwik Fleck is today recognized as one of the pioneers of the historical sociology of science, his historical and epistemological writings, most of them dating from the 1930s, long remained practically unknown. They were rediscovered following the mention of Fleck's principal work, the monographGenesis and Development of a Scientific Fact(1935) in the preface of Kuhn'sThe Structure of Scientific Revolutions(1962), and thanks to the efforts of W. Baldamus (1977) and his student T. Schnelle (1982) and of the editors of the (...) English translation of Fleck's book, R. K. Merton and T. J. Trenn. Fleck's work was studied by several scholars and was the subject of two meetings: “Colloquium Ludwik Fleck” (Hamburg, 1981) organized by L. Schaffer and T. Schnelle, and a symposium organized by R. S. Cohen (Berlin, 1984). Some of the papers presented at these meetings were published in Cohen and Schnelle 1986. Today, more than fifty years after the publication of his principal study, Fleck is on his way to becoming a “classic” of the sociology of science and of epistemology. (shrink)