History of the Peloponnesian War

Men of Athens, my exhortation shall be short, but with valiant men it hath as much force as a longer, and is for a remembrance rather than a command.

Let no man think, because it is in the territory of another, that we therefore precipitate ourselves into a great danger that did not concern us. For in the territory of these men, you fight for your own. If we get the victory, the Peloponnesians will never invade our territories again, for want of the Boeotian horsemen. So that in one battle you shall both gain this territory and free your own.