Qin people feel sorry for themselves, and later people mourn for them; Later generations grieved, failed to learn from it, and let future generations mourn for future generations.

The ruler of Qin had no time to lament his own demise, but let future generations lament; If future generations lament instead of learning from it, then future generations will also lament.

Emperor Huan of the Eastern Han Dynasty favored eunuchs, which led eunuchs to collude with each other, monopolize state affairs and frame Zhongliang. Mars, Du Mi and other Zhongliang ministers rallied Guo Tai, a former student, and tried their best to eradicate eunuchs. In AD 166, eunuchs falsely accused Mars and others of rebellion in front of Emperor Huan. Emperor Huan listened to his words and ordered Mars and other loyal ministers to be put into prison, with hundreds of people. This is a famous partisan struggle in history.

At that time, Dou Wu's daughter was a queen, and Dou Wu was made a marquis. He is honest and never bullies others. Seeing the eunuch's behavior, he was very angry. He wrote to Emperor Huan: If the eunuch continues like this, he will be like the second Qin Dynasty, because he gave Pang Chen too much power, which led him to rebel and eventually lost his country. Your majesty should learn a lesson and don't make the same mistake again! After Dou Wu's reminder, Emperor Huan realized his mistake, so he released others and ended the party struggle disaster.