Zhuangzi says: “To guard yourself against thieves who slash open suitcases, rifle through bags and smash open boxes, one should strap the bags and lock them. The world at large knows that this shows wisdom. However, when a master thief comes, he simply picks up the suitcase, lifts the bag, carries off the box and runs away with them, his only concern being whether the straps and locks will hold! In such an instance, what seemed like wisdom on the part of the owner surely turns out to have been of use only to the master thief!”