278 AFRICAN POLITICAL SYSTEMS
//. Tribal System
What is a Nuer tribe? The most obvious characteristic is its territorial unity and exclusiveness, and this was even more marked before European conquest than to-day. The population of a tribe varies from a few hundreds among some small tribes to the west of the Nile—if these are rightly regarded as tribes, for very little research was conducted in that area—to many thousands. Most tribes have a population of over 5,000 and the largest number between 30,000 and 45,000 souls. Each tribe is economically self-sufficient, having its own pastures, water-supplies, and fishing reservations, which its members alone have the right to exploit. It has a name which is the symbol of its distinction. The tribesmen have a sense of patriotism: they are proud to be members of their tribe and they consider it superior to other tribes. Each tribe has within it a dominant clan which furnishes a kinship framework on which the political aggregate is built up. Each also regulates independently its age-set organization.
None of the above-mentioned attributes clearly make a formal distinction between a tribe and its divisions. The simplest definition states that a tribe is the largest community which considers that disputes between its members should be settled by arbitration and that it ought to combine against other communities of the same kind and against foreigners. In these two respects there is no larger political group than the tribe and all smaller political groups are sections of it.
Within a tribe there is law: there is machinery for settling disputes and a moral obligation to conclude them sooner or later. If a man kills a fellow tribesman, it is possible to prevent, or curtail, a feud by payment of cattle. Between tribe and tribe there is no me^jis of bringing together the parties to a dispute and compensation is neither offered nor demanded. Thus, if a man of one tribe kills a man of another tribe, retribution can only take the form of intertribal warfare. It must not be supposed that feuds within a tribe are easy to conclude. There is considerable control over retaliation within a village, but the larger the local community the more difficult settlement becomes. When two large divisions of a tribe are concerned in a feud, the chances of immediate arbitration and settlement are remote. The force of law varies with the distance in tribal structure that separates the