This chapter draws upon the analysis of historical, philosophical, and epistemological roots of the movement of positive psychology because the major historical roots for positive psychology are evidently still the same. It also considers aspects of positive psychology in this new phase, often contrasting positive and mainstream psychology to more clearly illuminate the foundations, horizons, and values of positive psychology. Multiple paradigms and multiple theories within each of the paradigms give positive psychology an array of horizons and assumptions from which to protest. To understand the science and movement of positive psychology, the chapter starts by looking through Aristotle's model of human nature and development. Another more systematic way to explicate positive psychology's assumptions and foundations is to ask what kind of theories of human motivations mainstream psychology puts into the “witch's caldron” as compared with the questions that positive psychology raises.