First published in 1985. The purpose of this book reflects the 1983 Piaget Society decision to contribute some ideas to a critical problem in psychology: how the structure and function of intelligence and affectivity are developmentally related. Although this is a fundamental question in psychology, it has largely been ignored at different periods in its history. With the maturing of the cognitive sciences in the past quarter of a century, there today is a recrudescence of interest in the ways in which affect influences cognition.