Taking a broad view of his results, Piaget shows that they reveal several stages in the gradual development of the child’s conceptualization of his actions. In analysing each stage, Piaget argues that the child’s concept of his own action cannot be considered a simple matter of ‘enlightenment’, but must actively be reconstructed from his experience. This view has always been at the core of Piaget’s work, and a new area of the child’s mental world is here given definitive treatment.