History of the Peloponnesian War

Our fathers, at any rate, by withstanding the Medes—though they did not begin with such resources [as we have], but had even abandoned what they had—and by counsel, more than by fortune, and by daring, more than by strength, beat off the barbarian, and advanced those resources to their present height. And we must not fall short of them; but must repel our enemies in every way, and endeavour to bequeath our power to our posterity no less [than we received it].