The result of a deep research work sustained for more than two decades, this book studies the construction of social knowledge from a constructivist perspective inherited from Piagetian thought. It thus advances in a process of revision and discussion, while maintaining crucial aspects of this current for the approach to the construction of the subject and the object of knowledge, in the search for the elaboration of an explanatory theory for the formation of new knowledge. A collaborative proposal between different disciplines of potential interest for the different actors who study and intervene in this field.