The term social order can be used in two senses. In the first sense, it refers to a particular set or system of linked social structures, institutions, relations, customs, values and practices, which conserve, maintain and enforce certain patterns of relating and behaving. Examples are the ancient, the feudal, and the capitalist social order. In the second sense, social order is contrasted to social chaos or disorder, and refers to a stable state of society in which the existing social order is accepted and maintained by its members. The problem of order or Hobbesian problem, which is central to much of sociology, political science and political philosophy, is the question how and why it is that social orders exist at all.