防微杜渐 — “To nip a problem in the bud”

After Emperor He of the Eastern Han Dynasty ascended the throne, Empress Dowager Dou monopolized power. Her elder brother, Dou Xian, served as a Grand General and appointed his brothers to key civil and military positions, thus controlling the nation's military and political affairs.

Many officials were worried about this situation and feared for the Han empire. Ding Hong, a highly learned minister with deep knowledge of classics, was one of them. Ding Hong was indignant at Empress Dowager Dou's authoritarianism and resolved to eliminate this hidden danger for the country.

A few years later, a solar eclipse occurred, which was considered an inauspicious omen at the time. Ding Hong seized this opportunity to submit a memorial to the emperor, pointing out the harm caused by the Dou family's excessive power to the state and suggesting a swift change to this situation.

Emperor He had already sensed this problem and planned to address it. He promptly dismissed Dou Xian from his post, leading Dou Xian and his brothers to commit suicide.

In his memorial to Emperor He, Ding Hong advised that if the emperor personally wanted to rectify governance, he should pay attention to prevention when problems were just beginning to sprout, thereby eliminating potential troubles and ensuring the long-term peace and stability of the nation.