Ludwik Fleck is known mainly for his pioneering studies of science as a social activity. This text investigates a different aspect of Fleck’s epistemological thought—his engagement with normative aspects of medicine and public health and their political underpinnings. In his sinuous professional trajectory, Fleck navigated between two distinct thought styles: fundamental microbiological research and practice-oriented investigations of infectious diseases. Fleck’s awareness of tensions between these two approaches favored the genesis of his theoretical reflections. At the same time, his close observation (...) of medical and epidemiological practices led him to the conclusion that collectively produced scientific facts are situated and fragile. Thought collectives, Fleck explained, can err or yield to external pressures, with potentially disastrous consequences. While Fleck the reflexive experimental scientist has been creatively translated into the science studies idiom, Fleck the reflexive practical microbiologist and public health expert still awaits inspired translation. (shrink)

The rediscovery in the mid-1970s of Ludwik Fleck's initially neglected monograph, Entstehung und Entwicklung einer Wissenschaftlichen Tatsache, published in 1935 and translated in 1979 as Genesis and Development of a Scientific Fact, has resulted in extensive, still ongoing, secondary writings, mainly within the humanities. Fleck has been interpreted as furthering a relativistic conception of science. Nowadays, he is often viewed as an important contributor to contemporary sociology of science and a forerunner to Thomas Kuhn. Fleck's account of the Wassermann reaction, (...) which forms the basis of his epistemology, has been praised as developed by a scientist well acquainted with the field in question. Because of the scarcity of available material on Fleck, however, the question of his sources has remained an unsolved issue. In the present article, an alternative reading is suggested. By focusing on the scientific content of the monograph, mainly neglected in the modern interpretations of Fleck, and on the so far overlooked sources of his writings traced back to their German origin, a better understanding of Fleck's account of the Wassermann reaction can be given. The consequences of this alternative reading for the conception of Fleck's monograph and for the impetus of his mission are discussed. (shrink)

Ludwik Fleck’s theory of thought-styles has been hailed as a pioneer of constructivist science studies and sociology of scientific knowledge. But this consensus ignores an important feature of Fleck’s epistemology. At the core of his account is the ideal of ‘objective truth, clarity, and accuracy’. I begin with Fleck’s account of modern natural science, locating the ideal of scientific objectivity within his general social epistemology. I then draw on Fleck’s view of scientific objectivity to improve upon reflexive accounts of the (...) origin and development of the theory of thought-styles, and reply to objections that Fleck’s epistemological stance is self-undermining or inconsistent. Explicating the role of scientific objectivity in Fleck’s epistemology reveals his view to be an internally consistent alternative to recent social accounts of scientific objectivity by Harding, Daston and Galison. I use these contrasts to indicate the strengths and weaknesses of Fleck’s innovative social epistemology, and propose modifications to address the latter. The result is a renewed version of Fleck’s social epistemology, which reconciles commitment to scientific objectivity with integrated sociology, history and philosophy of science. (shrink)