Utilities of the third class, consisting in pleasures which only exist while being enjoyed, and services which only exist while being performed, cannot be spoken of as wealth, except by an acknowledged metaphor.

• 第三类效用，即只在享用时才存在的快乐和只在执行时才存在的服务，除了可比喻为财富外，不能称为财富。 对于财富这一概念来说，最重要的是可以被积累。