不肖：品行不好，不正派。观察他所交往的是些什么人，就能看出他是品德好的人还是不正派的人。

If you spend too much time thinking about a thing, you’ll never get it done.

The proof of a system's value is its existence.

"The most important thing in science is not so much to obtain new facts as to discover new ways of thinking about them."

做这件事的唯一方法就是去做。

世界并不友善，但它是正确的。