The following quotation comes from The Melian Dialogue. It is part of the reply of the Athenians to the Melians (a Lacedaemonian colony that would not willingly submit to Athenian domination).
..... For ourselves, we shall not trouble you with specious pretences—either of how we have a right to our empire because we overthrew the Mede, or are now attacking you because of wrong that you have done us—and make a long speech which would not be believed; and in return we hope that you, instead of thinking to influence us by saying that you did not join the Lacedaemonians, although their colonists, or that you have done us no wrong, will aim at what is feasible, holding in view the real sentiments of us both; since you know as well as we do that right, as the world goes, is only in question between equals in power, while the strong do what they can and the weak suffer what they must.
..........— Thucydides (c. 460 B.C.E. – c. 395 B.C.E.), Greek historian.
The History of the Peloponnesian War (c. 431 B.C.E.) translated by Richard Crawley, Book V, Chapter XVII, Section 89.