The nature of water is that it avoids heights and hastens to the lowlands. When a dam is broken the water cascades with irresistible force. Now the shape of an army resembles water. Take advantage of the enemy's unpreparedness; attack him when he does not expect it; avoid his strength and strike his emptiness, and like water, none can oppose you. (IV.20 Chang Yu)

A key tenet of Sun Tzu's strategic philosophy is to attack the opposing side's weaknesses. "Now an army may be...

Sun Tzu's Art of War states, "Therefore, when I have won a victory I do not repeat my tactics but...