You cannot pull that out of theory.

而不是从理论推导出。

麻省理工公开课 - 固态化学导论课程节选

And my purpose will be not to say something as a postulate, but to show you where everything comes from, and it's best for you if you try to follow the logic.

我的目的不是,简单地告诉你们一个假说,而是给你们讲清楚这个理论的来龙去脉,如果你们能理解推导过程那就再好不过

耶鲁公开课 - 基础物理课程节选