My talk honors the contribution of Ithiel de Sola Pool to empirical political theory, a field pioneered by Pool, David Easton, and Gabriel Almond, inter alia. Pool's 1967 edited volume, Contemporary Political Science: Toward Empirical Theory illustrates some of the important early works in this field, a field designed to generate political theory from the systematic examination of empirical data. To demonstrate the kind of work Pool developed, I begin my talk by suggesting what studying altruism and genocide taught me about broader themes in political, social, and moral theory. I then suggest how I developed a new theory of moral choice in order to explain the surprising finding that identity trumped choice for all the participants I interviewed about their actions during the Holocaust and World War II, from Nazis and bystanders to rescuers of Jews. This paper thus summarizes the highlights of the 2010 Pool Lecture to provide a few illustrations of the empirical findings that led me to develop an identity-based theory of moral choice.