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AFRICAN POLITICAL SYSTEMS
of his non-membership of other groups of the same type which he stands outside of, and he is likewise not a member of the same community in virtue of his membership of a segment of it which stands in opposition to its other segments. Hence a man counts as a member of a political group in one situation and not as a member of it in a different situation, e.g. he is a member of a tribe in relation to other tribes and he is not a member of it in so far as his segment of the tribe is opposed to other segments. In studying the Nuer political constitution, it is therefore essential that we
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DIAGRAM No. II
view it together with those of their enemies as a single political system, for the outstanding structural characteristic of Nuer political groups is their relativity. A tribal segment is a political group in relation to other segments of the same kind, and they jointly form a tribe only in relation to other Nuer tribes and to adjacent foreign tribes which form part of their political system, and without these relations very little meaning can be attached to the concepts of 'tribe* and 'tribal segment'. That the distinction and individuality of a political group is in relation to groups of the same kind is a generalization that embraces all Nuer local communities, from the largest to the smallest.
The relation between tribes and between segments of a tribe