This is the first systematic analysis of Baldwin's genetic epistemology and its relation to the contemporary social sciences. It is prepared by ten psychologists, philosophers, and educators—including Piaget, Kholberg, and Campbell—from in-depth conceptual and empirical perspectives. This volume provides a comprehensive account of Baldwin's philosophical psychology, social and cognitive developmentalism, functionalism, symbolic interactionism, idealist aesthetics, and theoretical biology. Moreover, it provides the first bibliography and commentary of his work to appear in print.