They [spies] cannot be properly managed without benevolence and straightforwardness.

When you know both yourself as well as your competition, you are never in danger. To know yourself and not others, gives you half a chance of winning. Knowing neither yourself or your competition puts you in a position to lose.

There is an intelligent way to eat a live frog - I just don't know what it is.

Those who excel in war first cultivate their own humanity and and maintain their laws and institutions. By these means they make their governments invincible.

When your opponent gives you an opening, be swift as a hare.

No ruler should put troops into the field merely to gratify his own spleen; no general should fight a battle simply out of pique.

He will win who has military capacity and is not interfered with by the sovereign.