Hence that general is skilful in attack whose opponent does not know what to defend; and he is skilful in defence whose opponent does not know what to attack. 310

O divine art of subtlety and secrecy! Through you we learn to be invisible, through you inaudible; 311 and hence we can hold the enemy’s fate in our hands. 312

You may advance and be absolutely irresistible, if you make for the enemy’s weak points; you may retire and be safe from pursuit if your movements are more rapid than those of the enemy. 313

If we wish to fight, the enemy can be forced to an engagement even though he be sheltered behind a high rampart and a deep ditch. All we need do is attack some other place that he will be obliged to relieve. 314