But if they are states at all, they embody some common conception of the good, some common aspirations of all their members.
The Greek doctrine that the essence of the state consists in community of purpose is the counterpart of the notion often held in modern times that the essence of the state is force.

The existence of force is for Plato and Aristotle a sign not of the state but of the state's failure.
It comes from the struggle between conflicting misconceptions of the good.

In so far as men conceive the good rightly they are united.

The state represents their common agreement, force their failure to make that agreement complete.

The cure, therefore, of political ills is knowledge of the good life, and the statesman is he who has such knowledge, for that alone can give men what they are always seeking.
If the state is the organisation of men seeking a common good, power and political position must be given to those who can forward this end.