Change His Choices, Not His Mind

Near the start of the third chapter of The Art of War, Sun Tzu makes one of his boldest claims. In Lionel Giles’s 1910 translation: “to fight and conquer in all your battles is not supreme excellence; supreme excellence consists in breaking the enemy’s resistance without fighting.” In Chinese, 不战而屈人之兵，善之善者也.

It is tempting to read this as a kind of mind control: the best general changes what the enemy wants, so that he gives up on his own. I do not think the text supports that. To see why, start with how Sun Tzu ranks the ways to win.

He gives a clear order: 上兵伐谋，其次伐交，其次伐兵，其下攻城. Giles translates it: “the highest form of generalship is to baulk the enemy’s plans; the next best is to prevent the junction of the enemy’s forces; the next in order is to attack the enemy’s army in the field; and the worst policy of all is to besiege walled cities.” Many modern translators read the second step, 伐交, as “attack his alliances.” Giles’s own note gives the same meaning: “isolating him from his allies.”

Why is a siege the worst? Sun Tzu gives his reason, and it is about cost. Building shields and siege equipment “will take up three whole months,” and building earth mounds against the walls “will take three months more.” Then the general, “unable to control his irritation,” sends his men up the walls, “with the result that one-third of his men are slain, while the town still remains untaken.” The chapter’s first line states the principle: “the best thing of all is to take the enemy’s country whole and intact; to shatter and destroy it is not so good.”

So the ranking is about what you keep. The higher methods cost less and destroy less. As an engineering teacher, I recognize this as an optimization: reach the goal while losing as little as possible, on both sides, because what survives is what you win.

Now, how can resistance be broken without fighting? The economist Thomas Schelling studied this question in The Strategy of Conflict (1960). He described a “strategic move” as a move that influences the other person’s choice by affecting his expectations of how you will behave. Deterrence works this way. The enemy does not stop wanting what he wants. He changes his choice because he now expects a different result.

That fits Sun Tzu much better than mind control does. When you baulk the enemy’s plans, his plan no longer leads where he hoped. When you separate him from his allies, he can no longer expect their help. In both cases, his values stay the same: he still wants to survive and keep his state. What changes is what he can expect from each choice. Given his own values, giving up becomes the better option.

There is a reason this works, and it comes from philosophy of mind. Daniel Dennett, in The Intentional Stance (1987), described how we predict other people: we assume they have beliefs and desires and will act sensibly to get what they want. That is how a general predicts that an isolated, outplanned enemy will yield. And it only works because the enemy’s desires stay fixed. If you really rewrote what he wanted, you would lose the very thing that let you predict him.

A reader who knows the rest of the book might object here. In chapter 7, Sun Tzu writes, in Giles’s words: “A whole army may be robbed of its spirit; a commander-in-chief may be robbed of his presence of mind.” In Chinese, 三军可夺气，将军可夺心. Isn’t that changing the enemy’s mind? In one sense, yes. But it changes his state, not his goals. An army that has lost its spirit still wants to survive and win. It just has less courage to try. A general who has lost his presence of mind still wants the same victory. He just judges worse. Even here, Sun Tzu changes the enemy’s condition and leaves what he wants alone.

So “breaking the enemy’s resistance without fighting” means changing his situation, not his mind in any deep sense, and trusting his mind to do the rest. That is less dramatic than mind control, and closer to what Sun Tzu actually describes. In my field, we would say Sun Tzu leaves the enemy’s objective function alone and changes his options, because an opponent whose goals you understand is predictable, and a predictable opponent can be led to the choice you need.