If anyoney, no matter who, were given the opportunity of choosing from amongst all the nations in the world the set of beliefs which he thought best, he would inevitably, after careful consideration of their relative merits, choose that of his own country. Everyone without exception believes his own native customs, and the religion he was brought up in, to be the best; and that being so, it is unlikely that anyone but a madman would mock at such things. . . . One can see by this what custom can do, and Pindar, in my opinion, was right when he called it "king of all."
— Herodotus, The Persian Wars