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

The control of large numbers is possible, and like unto that of small numbers, if we subdivide them.

Concentrate your energy and hoard your strength.

Thus the skilful general conducts his army just as though he were leading a single man, willy-nilly, by the hand.

When you shoot a bow and arrow, you aim at the clouds, not because you expect to hit them, but so that you may reach the distant target on the ground.

Winning isn't enough. The acme of all skill is to defeat your enemy before taking the field.

When you are ignorant of the enemy but know yourself, your chances of winning or losing are equal.