Is a forgotten subject central to the future development of sciences? Jean Piaget on the interrelationship between ontogeny and history

Jean Piaget applied his developmental psychology to describe mind and reason of archaic humans and ancient philosophers. He studied children to have a scientific instrument for the research of the psychological development of the whole humankind from the Stone Ages over ancient civilizations to modernity. However, he never wrote a comprehensive monograph regarding this subject, apart from his books on the reconstruction of the history of sciences. Usually, he made the comparisons of children and historical phenomena by inserting some remarks in his books about children's psyche. This article collects these remarks and shows that they cover all relevant subjects regarding the child's psyche including logic, physics, social issues, morals, and politics. It is argued that Piaget himself was insecure on how to develop a general theory of the psychological development of the humankind. That is the reason why he did refrain from investing more research in this transfer work. The article shows, however, that it is possible and necessary to develop such a theory in order to enhance the future development of the humanities and the social sciences. Without this knowledge it is impossible to reconstruct the history of psyche, reason, culture, sciences, philosophy, law, religion, morals, politics, etc.