数学是一门活生生的学科，随着新的思想和发现不断演变。

The other thing about modern society and why it causes this anxiety, is that we have nothing at its center that is non-human. We are the first society to be living in a world where we don't worship anything other than ourselves. We think very highly of ourselves, and so we should; we've put people on the Moon, done all sorts of extraordinary things. And so we tend to worship ourselves.

法律义务不仅仅是道德义务加上制裁。

懒惰奢侈，招来贫困；勤劳节俭，累积财富。