His criticism of Plato in the light of history, in Book II.

chap, v., though as a criticism it is curiously inept, reveals his own attitude admirably: "Let us remember that we should not disregard the experience of ages; in the multitude of years, these things, if they were good, would certainly not have been unknown; for almost everything has been found out, although sometimes they are not put together; in other cases men do not use the knowledge which they have." Aristotle in his Constitutions had made a study of one hundred and fifty-eight constitutions of the states of his day, and the fruits of that study are seen in the continual reference to concrete political experience, which makes the Politics in some respects a critical history of the workings of the institutions of the Greek city state.

In Books IV., V., and VI.

the ideal state seems far away, and we find a dispassionate survey of imperfect states, the best ways of preserving them, and an analysis of the causes of their instability.
It is as though Aristotle were saying: "I have shown you the proper and normal type of constitution, but if you will not have it and insist on living under a perverted form, you may as well know how to make the best of it." In this way the Politics, though it defines the state in the light of its ideal, discusses states and institutions as they are.
Ostensibly it is merely a continuation of the Ethics, but it comes to treat political questions from a purely political standpoint.
This combination of idealism and respect for the teachings of experience constitutes in some ways the strength and value of the Politics, but it also makes it harder to follow.

The large nation states to which we are accustomed make it difficult for us to think that the state could be constructed and modelled to express the good life.