Essay Reviews
Beginning with research published in the 1920's, Jean Piaget's description of the development of cognition is a monumental achievement, the reason that he is one of the most influential psychologists alive today. During the past decade, increasing numbers of American educators have become interested in the implications of Piaget's work for the classroom. Early attempts at applying Piaget's theory to education were based on his theory of cognitive stages which had essentially been completed by the 1950's. Stage theory was, however,only a part of the task which Piaget had set for himself at the outset of his career, a model of psychological development firmly grounded in both modern evolutionary theory and in philosophy. Biology and Knowledge is the captstone of that effort, the result of nearly a half century of work attempting to link the two fields. This model—resting on the notion of a macrogenetic sequence of biological-epistemological structures—implies and suggests research on a complementary notion, the process of equilibration. This process has in fact been the focus of much of Piaget's research during the past decade.