 The common good is an important concept in political philosophy because it plays a central role in philosophical reflection about the public and private dimensions of social life. Let’s say that “public life” in a political community consists of a shared effort among members to maintain certain facilities for the sake of common interests. “Private life” consists of each member’s pursuit of a distinct set of personal projects. As members of a political community, we are each involved in our community’s public life and in our own private lives, and this raises an array of questions about the nature and scope of each of these enterprises. For example, when are we supposed to make decisions based on the common good? Most of us would agree that we are required to do so when we act as legislators or civil servants. But what about as journalists, corporate executives or consumers? More fundamentally, why should we care about the common good? What would be wrong with a community whose members withdraw from public life and focus exclusively on their own private lives? These are some of the questions that motivate philosophical discussions of the common good.