296 AFRICAN POLITICAL SYSTEMS
segments. It is these relations, together with the tribal and intertribal contacts with foreign peoples, that we define as the Nuer political system. In social life the political is combined with other systems, particularly the clan system and the age-set system, and we have considered what relation they bear to the political structure. We have also mentioned those ritual specialisms which have political significance. The political system has been related to environmental conditions and modes of livelihood.
The Nuer constitution is highly individualistic and libertarian. It is an acephalous state, lacking legislative, judicial, and executive organs. Nevertheless, it is far from chaotic. It has a persistent and coherent form which might be called 'ordered anarchy*. The absence of centralized government and of bureaucracy in the nation, in the tribe, and in tribal segments—for even in the village authority is not vested in any one—is less remarkable than the absence of any persons who represent the unity and exclusiveness of these groups.
It is not possible from a study of Nuer society alone, if it be possible at all, to explain the presence and absence of political institutions in terms of their functional relationship to other institutions. At best we can say that certain social characteristics seem to be consistent. Environmental conditions, mode of livelihood, territorial distribution, and form of political segmentation appear to be consistent. So do the presence of clans with genealogical structure and a developed age-set system seem to gc together with absence of political authority and of class-stratification. Comparative studies alone will show whether generalizations of such a kind are true and, moreover, whether they are useful. We cannot here discuss these questions and will only say, in conclusion, that the consistency we perceive in Nuer political structure is one of process rather than of morphology. The process consists of complementary tendencies towards fission and fusion which, operating alike in all political groups by a series of inclusions and exclusions that are controlled by the changing social situation, enable us to speak of a system and to say that this system is characteristically defined by the relativity and opposition of its segments.