This article proposes a model of positive health based on a human-system framework. Such a framework is comprehensive in that (a) it encompasses all of the human system's behavioral subsystems (biochemical, physiological, perceptual, cognitive, and interpersonal), and (b) it permits a higher asymptote of health conceptualization and measurement than that afforded by Western biomedical theory. The article sets forth the conceptual basis of the model and reviews empirical studies that support the model. Finally, the article explores implications of the model for health research, for programs of health enhancement, and for the role of the behavioral sciences in health theory.