[Contradiction, incitement or hindrance to the development of knowledge].

Based on sequences of psychological examinations and the analysis of mental functioning of school children with learning difficulties, the authors propose a discussion around the concept of contradiction, such as envisaged by Piaget as having a fundamental role in the process of access to knowledge. The manner in which the dysfunction is manifested leads them to define different forms of reactions to the contradiction which compromises more or less seriously the development of knowledge. Finally, faced by the quasi existential confrontation which the contradiction represents for these children, they weigh the extent of its consequences on thought mechanisms.