The man of knowledge must be able not only to love his enemies but also to hate his friends.
Do I not destroy my enemies when I make them my friends?
In the end, we will remember not the words of our enemies, but the silence of our friends.
You have enemies? Good. That means you've stood up for something, sometime in your life.
Always forgive your enemies; nothing annoys them so much.
If we could read the secret history of our enemies, we should find in each [person's] life sorrow and suffering enough to disarm any hostility.
Every person acquires the stature of the enemy he wrestles with.
Never interrupt your enemy when he is making a mistake.
Money can't buy you friends, but you can get a better class of enemy.