In the problematic line for the investigation, the role of theory is fundamental, its formal explanatory or prescriptive positive status, its complex relationship with the experience of the subject, the emergence of other theoretical bodies from the confrontation, the relative criteria of truthfulness of the theorems that usually translate into certainty that hinder reflection and critical analysis, the work criteria that can be based on the critical use of theory or on formal or educational use, the logic of theoretical discourses and the changing nature of reality .