No ruler should put troops into the field merely to gratify his own spleen; no general should fight a battle simply out of pique. If it is to your advantage, make a forward move; if not, stay where you are. Anger may in time change to gladness; vexation may be succeeded by content. But a kingdom that has once been destroyed can never come again into being; nor can the dead ever be brought back to life.

Begin by seizing something which your opponent holds dear; then he will be amenable to your will.

Victory is the main object in war.

Military tactics are like unto water; for water in its natural course runs away from high places and hastens downwards... Water shapes its course according to the nature of the ground over which it flows; the soldier works out his victory in relation to the foe whom he is facing. Therefore, just as water retains no constant shape, so in warfare there are no constant conditions. He who can modify his tactics in relation to his opponent and thereby succeed in winning, may be called a heaven-born captain.

Know the enemy and know yourself.

The enlightened ruler is heedful, and the good general full of caution.

In warfare, there are no constant conditions. He who can modify his tactics in relation to his opponent will succeed and win.