Dr. Chapman claims that Piaget's use of developmental psychology as a means for addressing questions about the evolution of knowledge has been misunderstood by psychologists approaching his work exclusively from the perspectives of their own discipline. Reconstructing Piaget's intellectual biography makes possible a better understanding of the questions he originally posed and the answers he subsequently provided. Dr. Chapman concludes with an assessment of Piaget's relevance for contemporary psychology and philosophy and suggests ways in which Piagetian theory might be further developed.