So Herodotus makes the Nile answer to the Ister, and the valley of the Nile to the Red Sea.

In the Republic, Plato is flying in the air regardless of fact and possibility--in the Laws, he is making history by analogy.
In the former, he appears to be like some modern philosophers, absolutely devoid of historical sense; in the latter, he is on a level, not with Thucydides, or the critical historians of Greece, but with Herodotus, or even with Ctesias.
The chief object of Plato in tracing the origin of society is to show the point at which regular government superseded the patriarchical authority, and the separate customs of different families were systematized by legislators, and took the form of laws consented to by them all.

According to Plato, the only sound principle on which any government could be based was a mixture or balance of power.

The balance of power saved Sparta, when the two other Heraclid states fell into disorder.

Here is probably the first trace of a political idea, which has exercised a vast influence both in ancient and modern times.