古今的变化，不是改变其根本道理，而是改变其方法。
不去尝试办不到的事情, 不去追求得不到的东西, 不居于不能持久的地位, 不推行不可重复的政策。
我只是在尽我所能地过好我的生活。
Courage is a virtue necessary not only in war, but in life as well.
The most important thing in science is not so much to obtain new facts as to discover new ways of thinking about them.