[Chang Yu says: "Presence of mind is the general’s most important asset. It is the quality which enables him to discipline disorder and to inspire courage into the panic-stricken." The great general Li Ching (A.D. 571-649) has a saying: "Attacking does not merely consist in assaulting walled cities or striking at an army in battle array; it must include the art of assailing the enemy’s mental equilibrium."] 28. Now a soldier’s spirit is keenest in the morning; [Always provided, I suppose, that he has had breakfast. At the battle of the Trebia, the Romans were foolishly allowed to fight fasting, whereas Hannibal’s men had breakfasted at their leisure. See Livy, XXI, liv. 8, lv. 1 and 8.] by noonday it has begun to flag; and in the evening, his mind is bent only on returning to camp. 29. A clever general, therefore, avoids an army when its spirit is keen, but attacks it when it is sluggish and inclined to return. This is the art of studying moods. 30. Disciplined and calm, to await the appearance of disorder and hubbub amongst the enemy:—this is the art of retaining self-possession. 31. To be near the goal while the enemy is still far from it, to wait at ease while the enemy is toiling and struggling, to be well-fed while the enemy is famished:—this is the art of husbanding one’s strength. 32. To refrain from intercepting an enemy whose banners are in perfect order, to refrain from attacking an army drawn up in calm and confident array:—this is the art of studying circumstances. 33. It is a military axiom not to advance uphill against the enemy, nor to oppose him when he comes downhill. 34. Do not pursue an enemy who simulates flight; do not attack soldiers whose temper is keen. 35. Do not swallow a bait offered by the enemy. [Li Ch’uan and Tu Mu, with extraordinary inability to see a metaphor, take these words quite literally of food and drink that have been poisoned by the enemy. Ch’en Hao and Chang Yu carefully point out that the saying has a wider application.] Do not interfere with an army that is returning home.