The Art of War

by Sun Tzu

He who relies solely on warlike measures shall be exterminated; he who relies solely on peaceful measures shall perish.

If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.

So in war, the way is to avoid what is strong and to strike at what is weak.