Possessing methodological rules which limit the competence of psychological analysis to questions of fact alone as opposed to those of validity or foundations, but taking account of the autonomy of these questions of fact, we shall now try in Chapter VIII to apply the genetic method to the study of some general psychological problems raised by mathematical thought. By general problems we understand those which exist independently of formalisation: the nature of "structures" in Bourbaki's sense, self-evidence and its variations, the different forms of intuition, and finally invention and discovery. Each of these problems breaks down into two kinds of distinct questions, some relative to the formative stages of development (from the point of view of actions and operations) and others relative to the subject's consciousness, every general solution naturally presupposing the co-ordination of these two perspectives.