  (4) In (1935a) Fleck devotes only a few pages to the sociology of knowledge, and, moreover, he refers exclusively to the German translation of Lucien Levy-Bruhl’s book Das Denken der Naturvölker, 1921 and to Wilhelm Jerusalem’s paper of 1929. Clearly he did not know works of the “founders of sociology of knowledge”: Max Scheler and Karl Mannheim. Schnelle (1986) even claims that Fleck had acquired the basic information on the sociology of science from a popular paper published in Polish by Paweł Rybicki. When Fleck mentions the works of Durkheim, Levy Bruhl, Jerusalem or Gumplowicz, he does this superficially; he does not adopt any of their conceptions and is content with a general thesis that “What actually thinks within a person is not the individual himself but his social community” (Gumplowicz; quot.  from Fleck 1935a, § II.4). Fleck accuses them of ignoring the results of their research into the beliefs of traditional societies once they turn to scientific thinking, where they hold that “perceptions proper” displace mythical elements, and a traditional conviction on the existence of spirits and daemons is replaced with justified beliefs about “what physically is possible or impossible” (Levy-Bruhl, quot. from Fleck 1935a, § II.4). In contrast, Fleck claims that scientific thinking is an object of sociological examination to the same extent as mythical thinking.