beginning with a state which would express man's ideal nature, and
adapting it as well as may be to man's actual shortcomings from that
ideal, we must recognise that the state and all political machinery
are as much the expression of man's weakness as of his ideal
possibilities. The state is possible only because men have common
aspirations, but government, and political power, the existence of
officials who are given authority to act in the name of the whole
state, are necessary because men's community is imperfect, because
man's social nature expresses itself in conflicting ways, in the clash
of interests, the rivalry of parties, and the struggle of classes,
instead of in the united seeking after a common good. Plato and
Aristotle were familiar with the legislator who was called in by the
whole people, and they tended therefore to take the general will or
common consent of the people for granted. Most political questions are
concerned with the construction and expression of the general will,
and with attempts to ensure that the political machinery made to
express the general will shall not be exploited for private or
sectional ends.

Aristotle's mixed constitution springs from a recognition of sectional
interests in the state. For the proper relation between the claims of
"virtue," wealth, and numbers is to be based not upon their relative
importance in the good life, but upon the strength of the parties
which they represent. The mixed constitution is practicable in a state
where the middle class is strong, as only the middle class can mediate
between the rich and the poor. The mixed constitution will be stable
if it represents the actual balance of power between different classes
in the state. When we come to Aristotle's analysis of existing
constitutions, we find that while he regards them as imperfect
approximations to the ideal, he also thinks of them as the result of