This volume marks the 20th Anniversary Symposium of the Jean Piaget Society. Some of the American contributors were among the first to introduce Piaget to developmental and educational psychology in the United States, while some of the international contributors worked with Piaget to develop his program of genetic epistemology and continue to make significant contributions to it.

Within this volume the possibility of Piaget's paradigm is reviewed not only as the stuff of normal science, yielding fascinating empirical questions that linger within it, but also, and more...