History of the Peloponnesian War

"With regard then to what has been done before, why need we find fault with it at greater length than is expedient for what is doing now? But with respect to what will be hereafter, we must labour for it by supporting what is present; for it is our hereditary custom to acquire virtues by labours; and you must not change the fashion, if you have a slight superiority now in wealth and power; (for it is not right that what was won in want should be lost in abundance;) but must go to the war with good courage on many grounds; since the god has commanded it, and promised to take part with you himself; while the rest of Greece will all join you in the struggle, some for fear, and some for interest. Nor will you be the first to break the treaty;

for even the god himself considers it to have been violated, since he orders you to go to war; but you will rather come to its support after it has been wronged: for the breakers of it are, not those who defend themselves, but those who were the first aggressors.