Kill one, terrify a thousand.
They [spies] cannot be properly managed without benevolence and straightforwardness.
In war, numbers alone confer no advantage. Do not advance relying on sheer military power.
Carefully compare the opposing army with your own, so that you may know where strength is superabundant and where it is deficient.
Rapidity is the essence of war: take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots.
Build your opponent a golden bridge to retreat across.