The introduction asks the question of why social scientists should study virtues empirically. It offers five reasons: (1) humans are moral animals, (2) moral behavior can be understood as an expression of acquired traits, (3) it is psychologically realistic to think that ordinary humans can acquire and express virtue traits, (4) moral education is valuable, and (5) virtues are often taken to be essential to a good life. The Introduction then addresses three challenges that virtue scientists must face: (1) the absence of empirically oriented virtue theory, (2) the overreliance of simple survey design in psychology, and (3) virtue skeptics. The Introduction concludes with an outline of the chapters of the book and how these chapters comprise the sections of the book.