He who learns but does not think, is lost. He who thinks but does not learn is in great danger.
If you make a mistake and do not correct it, this is called a mistake.
The hardest thing of all is to find a black cat in a dark room, especially if there is no cat.
If you lead the people with correctness, who will dare not be correct?
To lead uninstructed people to war is to throw them away.
Heaven sends down its good and evil symbols and wise men act accordingly.