Both conflict and cooperation are ubiquitous features of human social life. Interests of individuals conflict with those of their neighbors because (among other reasons) material resources are scarce, ideals and values are diverse, and people care about their reputations and relative standing among their fellows. At the same time, individuals share a number of common interests and concerns, and this makes social cooperation possible. Among the most important of these common interests are the prevention and limitation of violent conflict and the protection of personal possessions. When these interests are secured and when environmental and economic conditions are reasonably favorable, people generally can live out their lives and engage in cooperative (and competitive) social activities without constant concern for their own survival and that of their loved ones. But it is not easy to secure persons and possessions when others may gain by attacking the former or seizing the latter. In fact, it requires two major social institutions--morality and government--working in a coordinated fashion to do so. This is one of the main themes of Hobbes's philosophy that will be developed in this book.