This article analyses three basic concepts of Ludwik Fleck’s Genesis and Development of a Scientific Fact. It shows first that Fleck’s notion of „directed perception“ is closely linked to Jakob von Uexküll’s writings on the „Umwelt“ of animals and humans. The article then proposes to regard the epistemological debates surrounding parapsychology as an important testing ground for the Fleckian concept of „mood“ and his concomitant hypotheses about „the tenacity of systems of opinion and the harmony of illusions“. It finally argues (...) that Fleck’s modification of Wilhelm Jerusalem’s idea of the „social consolidation“ of knowledge helps us to understand the indebtedness of Fleck towards early functionalist sociology as well as his strong belief in „specific historical laws governing the development of ideas“. The historical semantics of Fleck’s works hence proves that his insights are neither marginal nor revolutionary but rather deeply rooted within scientific traditions from the late 19th and early 20th centuries. (shrink)

This article looks at how fisheries biologists of the early twentieth century conceptualized and measured overfishing and attempted to make it a scientific object. Considering both theorizing and physical practices, the essay shows that categories and understandings of both the fishing industry and fisheries science were deeply and, at times, inextricably interwoven. Fish were both scientific and economic objects. The various models fisheries science used to understand the world reflected amalgamations of biological, physical, economic, and political factors. As a result, (...) scientists had great difficulty stabilizing the concept of overfishing and many influential scholars into the 1930s even doubted the coherence of the concept. In light of recent literature in history of fisheries and environmental social sciences that critiques the infiltration of political and economic imperatives into fisheries and environmental sciences more generally, this essay highlights both how early fisheries scientists understood their field of study as the entire combination of interactions between political, economic, biological and physical factors and the work that was necessary to separate them. (shrink)

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)