The text is the translation of the two chapters from Mary Douglas' book «How Institutions Think». According to Douglas, we to abandon the traditional understandings of institutions and return to the research program founded by Emil Durkheim's and Ludwig Fleck's works. In particular, institutions can be considered, following Fleck, as thought collectives that characterized by specific thought style. One element of the thought style is a style of classification. Douglas shows how, as the social conditions change, different classificatory schemes emerge and transform.