The importance of common sense for psychological theories is construed as a limiting condition that must be transcended if a particular psychological theory is expected to have generalizability across cultures and over history. Discussion on the pages of this journal, initiated by Jan Smedslund in 1978, has brought the common-sensical nature of the majority of psychological theories into psychologists' focus of attention. Smedslund has attempted to explicate ‘theorems’ of common sense that underlie thinking and activities of human beings in a culture—and that are shared by laypersons as well as by psychologists. This article approaches the issue of common sense in psychological theorizing from a developmental perspective. This perspective emphasizes the process of emergence of qualitatively new cognitive phenomena in the course of cultural history. It is argued that the ‘logical necessity’ based on the ‘theorems’ of common sense is itself ‘historical necessity’, as it results from the history of human cultures. Smedslund's ‘theorems’ of common sense can only be formal, but not substantive, analogues of theorems in geometry, since the latter are ahistorical, whereas the former constitute products of the history of cultures and individuals.