EN
This article is the second part of the discussion on Ludwik Fleck, the author of The genesis and development a scientifict fact. In this paper I discuss several research areas mentioned in the previous article, such as common knowledge and the theory of perception. I believe they can only be properly understood by using the Fleck's concept of individual as well as the meaning. According to Fleck, a member of modern society lives in several thought collectives. Each individual participates in the collective of common knowledge, which is formed by simplified scientific knowledge and the circulation of thoughts. On its way from the scientific journal to the school handbook the subjective author's view is being changed into proven scientific fact. Before someone becomes an expert and a member of esoteric circle of particular field or domain, he or she is just a laic, who goes to school and learns from the handbooks. Fleck, several decades before Norwood Hanson, pointed out the relation between scientific discoveries and the perception showing that the observation is related to the theory. Fleck's theory of perception is similar to that of Ludwig Wittgenstein, then used by Hanson. Fleck argued that without the knowledge it's impossible to perceive, you can look at something, but you don't see it. It seems like the perception is the matter of mentality and the knowledge is being provided by the thought collective. The novelty of Fleck's theory was the role of metaphors in the creation of perceived figures. There is no observations uninfluenced by the thinking, according to Fleck, it also applies to the common sense.