事情过后议论别人，身在局外议论局内人，是做学问的人最容易犯的毛病。在事后议论别人，往往将聪明人说得极其愚笨；身在局外议论局内的人，往往将困难的事情说得极其容易，这两种毛病都是由待人不忠诚、不宽容而引起的。

To light a candle is to cast a shadow.

One can't proceed from the informal to the formal by formal means.

Collaboration often leads to breakthroughs that individual effort cannot achieve.

The real challenge is not just to feed the world, but to nourish it in a sustainable way.