《淮南子·人间训》
一般性的人都只知道利就是利，弊就是弊，而只有圣人懂得弊可以转化为利，利可以转化为弊。
众人皆知利利而病病也，唯圣人知病之为利，知利之为病也。
Ordinary people only know that benefits are benefits and drawbacks are drawbacks, while only the wise understand that drawbacks can be transformed into benefits, and benefits can be transformed into drawbacks.