But if we are to think of actual politics as intelligible in the light of the ideal, we must think of that ideal as progressively revealed in history, not as something to be discovered by turning our back on experience and having recourse to abstract reasoning.

If we stretch forward from what exists to an ideal, it is to a better which may be in its turn transcended, not to a single immutable best.

Aristotle found in the society of his time men who were not capable of political reflection, and who, as he thought, did their best work under superintendence.

He therefore called them natural slaves.

For, according to Aristotle, that is a man's natural condition in which he does his best work.