ABSTRACT
WE have noted, in the first part of this work, that the operations of thought reach their form of equilibrium when they are formed into complex systems characterized by reversible combinativity (groupings or groups). But if a form of equilibrium marks the final limit of development, this does not explain either its initial phases or its constructive mechanism. In the second part, we were then able to locate the origin of operations in sensori-motor processes; the schemata of sensori-motor intelligence form the practical equivalent of concepts and relations, and their co-ordination into spatiotemporal systems of objects and movements even arrives, though still in a practical and empirical form, both at the conservation of the object, and at a correlative group structure (H.Poincaré’s group of experienced displacements). But it is obvious that this sensori-motor group simply constitutes a schema of behaviour, i.e. the equilibrated system formed by the various possible physical movements in near space, and that it in no way attains the rank of an instrument of thought.1 Certainly, sensori-motor intelligence lies at the source of thought, and continues to affect it throughout life through perceptions and practical sets. In particular, the role of perception in the most highly developed thought cannot be neglected, as it is by some writers when they pass too rapidly from neurology to sociology, and this role alone bears witness to the persistent influence of early schemata. But there is still a very long way to go from preverbal intelligence to operational thought before reflective groupings may be established, and
even if there is a functional continuity between the two extremes, the formation of a series of intermediate structures at several heterogeneous levels is indispensable.
