Thucydides,
The History of the Peloponnesian War
“ I am rather trying to recover one that is mine no longer; and the true lover of his country is not he who consents to lose it unjustly rather than attack it, but he who longs for it so much that he will go all lengths to recover it. For myself, therefore, Lacedaemonians, I beg you to use me without scruple for danger and trouble of every kind, and to remember the argument in every one’s mouth, that if I did you great harm as an enemy, I could likewise do you good service as a friend, inasmuch as I know the plans of the Athenians, while I only guessed yours. ”
