13. The Use of Spies

22

It is through the information brought by the converted spy that we are able to acquire and employ local and inward spies.

Tu Yu says: "through conversion of the enemy's spies we learn the enemy's condition." And Chang Yu says: "We must tempt the converted spy into our service, because it is he that knows which of the local inhabitants are greedy of gain, and which of the officials are open to corruption."