劳动是一切财富和一切文化的源泉。

Behind every technological breakthrough is the accumulation of countless failures.

A speculator is a man who observes the future, and acts before it occurs.

做数学的艺术在于找到那个包含所有普遍性萌芽的特殊案例。

There is no necessary connection between law and morality.

记忆是个狡猾的东西，它既可以是祝福也可以是诅咒。