Demosthenes

"As a vessel is known by the sound, whether it be cracked or not; so men are proved, by their speeches, whether they be wise or foolish."

"There is one safeguard known generally to the wise, which is an advantage and security to all, but especially to democracies as against despots - suspicion."

"Nothing is easier than self-deceit. For what each man wishes, that he also believes to be true." - Third Olynthiac