The chapter on the contest of armies moves from contending for position to contending for the mind. Sun Tzu says the spirit of an army, and the mind of its commander, can both be taken.
A fight is a collision of spirit against spirit before it is one of weapon against weapon.
三軍可奪氣,將軍可奪心
san jun ke duo qi, jiang jun ke duo xin
The spirit of a whole army can be taken away, and the mind of its commander can be taken away. (The Art of War, Contest of Armies, translated directly)