If you know neither the enemy nor yourself, you will succumb in every battle
Probe him and learn where his strength is abundant and where deficient.
In war, practice dissimulation and you will succeed.
If there is disturbance in the camp, the general's authority is weak. If the banners and flags are shifted about, sedition is afoot. If the officers are angry, it means that the men are weary.
The peak efficiency of knowledge and strategy is to make conflict unnecessary.
It is the business of a general to be serene and inscrutable, impartial and self-controlled.