历史学家的任务是复活那些被时间湮没的声音。

在背后夸奖别人。这会传回到你自己那里。

"In observational studies, we often have to rely on assumptions that are not directly testable."

"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

一个力学问题只有被简化为代数问题时才算解决。