Jean Piaget's theories about the development of intelligence and their implications for educational practice are explored. Before Piaget began studying the intellectual processes of children, researchers regarded them as "little adults." He derived his early fame from his theory of the "cognitive stages" of childhood. He realized the remarks of children had meaning and revealed modes of reasoning and judgment different from those of adults. The development of the child's thinking is marked by progressive clarification of ideas from global to differentiated thought. It progresses from absolute to more relativistic thought. It also changes from static to dynamic thought as the child matures. Piaget believed thinking and intelligence were synonymous and stressed thinking as a general capacity. Learning and thinking involve the participation of the learner. He believed knowledge was not transmitted verbally, but that it must be constructed and reconstructed by the thinker/learner. Activity is indispensable to learning and thinking. The way the child moves through the stages of development may be clarified by the concepts of schemata, assimilation, accommodation, and equilibrium. The four stages of cognitive development defined by Piaget are sensory-motor, preoperational, concrete operations, and formal operations. (DWH)