Sun Tzu wrote: "Know the enemy and know yourself, and in a hundred battles you will never be in danger. Know yourself but not the enemy, and you will win one and lose one. Know neither the enemy nor yourself, and you will be in danger in every battle."
This is the most quoted line in the Art of War — and the foundation of all strategic thinking. Victory comes from information. Defeat comes from ignorance — of yourself, of your opponent, or of both.
知彼知己，百战不殆；不知彼而知己，一胜一负；不知彼不知己，每战必殆。
知彼知己，百战不殆；不知彼而知己，一胜一负；不知彼不知己，每战必殆。
Reflection & Analysis · 寓意解读
Core Wisdom
The battle is won or lost before it begins — in the quality of your knowledge. The one who knows both sides holds all the cards.
Sun Tzu's formulation is precise: knowing yourself alone gives you 50-50 odds. Knowing the enemy alone is not tested. But knowing both gives you certainty. The implication is that self-knowledge is the foundation — you must understand your own strengths, weaknesses, and tendencies before you can accurately read another's.
This principle applies to every competitive domain — business, sports, politics, personal relationships. The negotiator who understands both sides' interests will always outperform the one who only understands their own.