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。