This book advances a personalist account of human beings to help us better understand and explain human persons, motivations, interests, and the social life to which they give rise. It offers an alternative to the standard views in contemporary sociology and most of the rest of social science. This book seeks to answer three big questions: What basic motivations and interests generate and direct human action? What is by nature good for human beings—that is, what are real human goods? How should we understand and explain the lack of goodness—sometimes even the definite destructiveness and evil—that are so prevalent and damaging in human life? Stated differently, this book seeks to better theorize the micro-foundations of social life, yet not from the rational-choice perspective that has dominated micro-foundations discourse. Altogether, the chapters make a case for the need to take seriously the reality and nature of subjective human motivations for generating action, to resist problematic versions of social situationism, to define carefully the relationship between distinct persons and their social environments, to identify which goods are by nature basic to human life, to develop a teleological account of human flourishing that defines objective human interests, and to understand how the natural human telos of flourishing can be compromised and destroyed by failure, destruction, and evil. It is guided by critical realism and by a broadly neo-Aristotelian view of human life as theoretical frameworks.