History of the Peloponnesian War

"As for the Thebans, they have done us many wrongs in the past, and you yourselves are well aware of this crowning outrage, which has brought us into our present plight.

They attempted to seize our city in time of peace, and furthermore on a day of festival; therefore we were justified in punishing them in accordance with the law which has universal sanction, that it is right to repel him who comes against you as an enemy;

and now we cannot reasonably be made to suffer on their account. For if you shall decide the question of justice by such considerations as your immediate advantage and their hostility, you will show yourselves to be, not true judges of what is right, but rather to be mere slaves of expediency.

And yet if the Thebans seem serviceable to you now, we and the rest of the Hellenes were of far greater service to you when you were in greater danger. For now you are attacking others and are a menace to them, but in that crisis, when the barbarian was threatening us all with slavery, these men were on his side.