13. By discovering the enemy’s dispositions and remaining invisible ourselves, we can keep our forces concentrated, while the enemy’s must be divided. 14. We can form a single united body, while the enemy must split up into fractions. Hence there will be a whole pitted against separate parts of a whole, which means that we shall be many to the enemy’s few. 15. And if we are able thus to attack an inferior force with a superior one, our opponents will be in dire straits. 16. The spot where we intend to fight must not be made known; for then the enemy will have to prepare against a possible attack at several different points; and his forces being thus distributed in many directions, the numbers we shall have to face at any given point will be proportionately few. 17. For should the enemy strengthen his van, he will weaken his rear; should he strengthen his rear, he will weaken his van; should he strengthen his left, he will weaken his right; should he strengthen his right, he will weaken his left. If he sends reinforcements everywhere, he will everywhere be weak. 18. Numerical weakness comes from having to prepare against possible attacks; numerical strength, from compelling our adversary to make these preparations against us. 19. Knowing the place and the time of the coming battle, we may concentrate from the greatest distances in order to fight. 20. But if neither time nor place be known, then the left wing will be impotent to succour the right, the right equally impotent to succour the left, the van unable to relieve the rear, or the rear to support the van. How much more so if the furthest portions of the army are anything under a hundred _li_ apart, and even the nearest are separated by several _li!_ 21. Though according to my estimate the soldiers of Yüeh exceed our own in number, that shall advantage them nothing in the matter of victory. I say then that victory can be achieved. 22. Though the enemy be stronger in numbers, we may prevent him from fighting. Scheme so as to discover his plans and the likelihood of their success. 23. Rouse him, and learn the principle of his activity or inactivity. Force him to reveal himself, so as to find out his vulnerable spots. 24. Carefully compare the opposing army with your own, so that you may know where strength is superabundant and where it is deficient. 25. In making tactical dispositions, the highest pitch you can attain is to conceal them; conceal your dispositions, and you will be safe from the prying of the subtlest spies, from the machinations of the wisest brains. 26. How victory may be produced for them out of the enemy’s own tactics—that is what the multitude cannot comprehend. 27. All men can see the tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved. 28. Do not repeat the tactics which have gained you one victory, but let your methods be regulated by the infinite variety of circumstances.