Lionel Giles

Hence the saying: 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.

On dispersive ground, therefore, fight not. On facile ground, halt not. On contentious ground, attack not.

war is of vital importance to the State.