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 traces some of the transformation that the fields of folk psychology and anthropology underwent in the late nineteenth century. Ludwik Fleck, in developing his sociology of knowledge, drew on both of these fields; a legacy that makes it possible to conceive of his epistemology as a theory of communication. Fleck, in grounding his understanding of the relationship between sociality and communication on insights from these two disciplines, proposed the morphological concept of an organic formation of all scientific knowledge. (...) Naturalising knowledge production in this manner, Fleck postulated a program of deciphering, reading, and translation that would relate all forms of knowledge back to the rules and conditions of its making. In this morphological conception of the processes of knowledge production, Fleck’s sociology bears significant similarities with the description of social institutions by French sociologists Marcel Mauss and Emile Durkheim, who also drew on insights from late-nineteenth-century folk psychology and anthropology. (shrink)