"Soldiering, my dear madam, is the coward's art of attacking mercilessly when you are strong, and keeping out of harm's way when you are weak. That is the whole secret of successful fighting. Get your enemy at a disadvantage; and never, on any account, fight him on equal terms."
 ~ 
Arms and the Man
 by 
George Bernard Shaw
You know nothing about Hope, that immortal, delicious  maiden forever courted forever propitious, whom fools have called deceitful, as if it were Hope that carried the cup of disappointment, whereas it is her deadly enemy, Certainty, whom she only escapes by transformation.
 ~ 
Daniel Deronda
 by 
George Eliot
"I remember a mass of things, but nothing distinctly; a quarrel, but nothing wherefore. O God, that men should put an enemy in their mouths to steal away their brains!"
 ~ 
Othello
 by 
William Shakespeare
"Treachery and violence are spears pointed at both ends; they wound those who resort to them worse than their enemies."
 ~ 
Wuthering Heights
 by 
Emily Bronte