A ruler who hides behind paid executioners soon forgets what death is.
譯文：古人最忌諱，表面對人順從，背地里卻反對。
容易得到的東西，是靠不住的；輕易許下的諾言，不值得信賴。
數(shù)學(xué)中最重要的是提出正確的問題。
The market is never wrong – opinions often are.