 As a philosophical concept, the common good is best understood as part of an encompassing model for practical reasoning among the members of a political community. The model takes for granted that citizens stand in a “political” or “civic” relationship with one another and that this relationship requires them to create and maintain certain facilities on the grounds that these facilities serve certain common interests. The relevant facilities and interests together constitute the common good and serve as a shared standpoint for political  deliberation.[1]  When citizens face various questions about legislation, public policy or social responsibility, they resolve these questions by appeal to a conception of the relevant facilities and the relevant interests. That is, they argue about what facilities have a special claim on their attention, how they should expand, contract or maintain existing facilities, and what facilities they should design and build in the future.