Just as Aristotelian metaphysics provided a new basis for the natural theology of Aquinas’s time, so too, positive psychology provides a basis for a natural moral theology in our own time. this book marshals the empirically verifiable findings of positive psychology that show the wisdom of the Christian tradition. Christian warnings about the dangers of greed, coveting a neighbor’s goods (social comparison), and pride find an empirical verification. Likewise, positive psychology vindicates the wisdom of Christian teaching on the importance of forgiveness, of gratitude, of humility, and of serving one’s neighbor. moreover, positive psychology also can be a service to Christian believers by helping them in their struggles with willpower, by providing new motivations for prayer, and by helping them identify their signature strengths. Finally, this book argues, in a variety of ways, that it is folly to think that even the best of psychology can serve as a replacement for Christianity.