David Brooks’s recent bestseller, The Social Animal: The Hidden Sources of Love, Character and Achievement, is an unusually rich book for one aimed at popular audiences. Writing in the dramatic form of a novel, Brooks develops unique and insightful reflections on the new “sciences” of human nature—neuroscience, genetics, and psychology—in a serious attempt to understand what they have to tell us about the contours of a life well lived. Comparing his method to Rousseau’s in Emile, Brooks narrates the lives of two protagonists, Harold (from an upper-class background) and Erica (from more difficult circumstances), intending to show concretely how the new sciences can illuminate our understanding of education, human development, daily choices—and even happiness and love. Although some critics have disparaged the book and its popular success, Brooks accomplishes something truly original in his synthesis, meriting the thoughtful consideration of readers.