Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win

If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.

When one treats people with benevolence, justice, and righteoousness, and reposes confidence in them, the army will be united in mind and all will be happy to serve their leaders'.

In the midst of chaos, there is also opportunity

He will win who, prepared himself, waits to take the enemy unprepared.

Bravery without forethought, causes a man to fight blindly and desperately like a mad bull.  Such an opponent, must not be encountered with brute force, but may be lured into an ambush and slain.