ABSTRACT
This chapter discusses certain conception of the psychological development of the child, a conception that we consider "paradoxical" in comparison with usual conceptions. It focuses on mechanisms of development, on the processes permitting the passage from one organization of behavior to another within each of the large stages of development. The chapter attempts to show how the infant comes to infer new significations to the objects (or people) with whom he or she interacts or how new determinants of behavior are defined. The concept of development as a series of revolutions stands in sharp contrast to the still prevailing view of development as a cumulation of itemized acquisitions. The successive disorganizations and reconstructions modify the child's relations with the environment as profoundly as the development of the capacity to grasp objects modifies the relations between the infant and the surrounding world.