The idea of successful development is used as the conceptual platform for a proposal that three basic principles of developmental science be expanded. Specifically, we propose that (a) developmental science needs to be reframed as a guide for what successful development is and how it is manifested at different times of the life course; (b) that the integrative emphasis of developmental science needs to emphasize the intersection of developmental domains as well as the integration of concepts from other disciplines; and (c) that careful distinctions need to be made between the life span approach (i.e., research focused on processes within one moment of the life course) and the life history approach (i.e., understanding stability and change across part of the life course). It is argued that the concept of successful development can be used to enrich developmental science.