The function of the mysterious

"A military expert used to say: "I dare not act as host [who takes the initiative] but act as guest [with reserve]. I dare not advance an inch, but I withdraw afoot." This is called marching without marching, threatening without arms, charging without hostility, seizing without weapons. No greater misfortune than making light of the enemy! When we make light of the enemy, it is almost as though we had lost our treasure - [compassion]. Thus, if matched armies encounter one another, the tenderer one is sure to conquer."