A unique form of political institution was to emerge in human bands: democracy. Democracy involves decision making through discussion, and rational processes of legitimation. I shall describe the processes of legitimation in detail later on, but here is a preliminary sketch. They involve: (1) participation in decision making, (2) limitation of the power and tenure of leaders, (3) open-access leadership offices and rational succession procedures, (4) debatable, amendable rules for the preservation of group order, (5) participation in rule making and the punishment of rule breakers.