If You Know The Enemy And

From Chapter 3 (Strategic Attack) of The Art of War, composed around the 5th century BC. The full passage continues: "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." The principle of self-knowledge as a prerequisite for tactical effectiveness influenced not only military doctrine but governance and personal philosophy across East Asia. Marcus Aurelius arrived at a similar emphasis on self-knowledge through the Stoic tradition.