The value of a commodity, or the quantity of any other commodity for which it will exchange, depends on the relative quantity of labor which is necessary for its production, and not on the greater or less compensation which is paid for that labor.

Science is not just about discovery, but also about the application of knowledge to improve human life.

人生苦短，必须快乐。

Mental processes are tools for mastering the environment.

我不听别人说什么，我只是出去尽我所能。