Shi Dan, styled Zhonggong, was a man of profound learning and unwavering integrity from Langya Dongwu in the Eastern Han Dynasty. His deep knowledge and upright character earned him the emperor's trust, leading to his appointment as Grand Minister of Works and later enfeoffment as the Marquis of Gaole.
During the reign of Emperor Yuan of Han, Empress Wang gave birth to a son who would later become Emperor Cheng. Consort Fu also had a son, exceptionally bright and beloved by Emperor Yuan, who was granted the title Prince Gong of Dingtao. Though Prince Gong of Dingtao died young, he left behind a son. Emperor Cheng ruled for over twenty years but had no heir, so upon his death, Prince Gong's son ascended the throne as Emperor Ai of Han.
After Emperor Ai of Han ascended the throne, his ministers proposed honoring his grandmother, Consort Fu, as Empress Dowager of Dingtao, and his mother, Lady Ding, as Queen of Dingtao. However, the imperial advisor Shi Dan firmly opposed this. Citing the rites and the proper order of hierarchy, human relations, and the cosmic balance of heaven and earth, he argued that such honors would disrupt the rightful positions. This stance earned him the lasting enmity of the two empresses dowager.
Soon after, someone advised the emperor to reform the currency, arguing that in ancient times, natural tortoise shells and cowries were used as money—limited in quantity and impossible to counterfeit, thus easy to control; but now, with copper coins being minted in ever-increasing amounts, currency depreciates, prices rise, and the people grow poor.
Emperor Ai of Han sought the opinion of his advisor Shi Dan, who found merit in the proposal, arguing that if the people were impoverished, the state would weaken, creating a vicious cycle. Shi Dan then instructed his scribe to record the suggestion for discussion and to draft an implementation plan.
However, when the relevant officials discussed the matter in detail, most argued that the coinage had been in circulation for so long that a sudden switch to tortoise shells and cowrie shells would be extremely difficult to implement. Shi Dan, hearing this, agreed that the change posed real challenges and decided to postpone any reform of the currency system.
By then, Shi Dan was advanced in years and had forgotten that he had previously expressed a different stance on the matter, which had already been recorded in the official documents. The draft of that record was leaked by a clerk.
Empresses Dowager Fu and Ding, already displeased with Shi Dan, seized this opportunity to attack him. They incited their clansmen to submit a memorial to Emperor Ai, accusing Shi Dan of leaking top-secret documents to the public as a high-ranking minister, causing social unrest and market chaos.
When Emperor Ai received the report, he referred it to his court officials for discussion. Some who already held a grudge against Shi Dan advocated for severe punishment. The emperor hesitated, leaving the matter unresolved. A few days later, two officials—Imperial Advisors Shen Xian and Gui Qin—submitted a memorial opposing the punishment, pleading for Shi Dan: "Minister Shi Dan's strategic insight is unmatched. In recent years, his handling of state affairs has been thorough and appropriate; few ministers can match him. Now, some are attacking him over a confidential matter to vent personal grievances. Though Shi Dan's opinions have wavered, lacking deep forethought, the fault of leaking secrets does not lie with him. To punish him on this charge would be improper."
This stirred up debate among the court officials. Some accused Shen and Gui, saying, "Precisely because Shi Dan holds high office and great power, his punishment should be more conspicuous. Shen and Gui did not oppose the public opinion at first, but now that the matter is public, they submit memorials praising Shi Dan—this is far too frivolous."
Emperor Ai of Han was the biological son of Empress Dowager Ding and the legitimate grandson of Empress Dowager Fu, so naturally he could not defy the wishes of the two empress dowagers just because Shi Dan had once been his teacher. He ultimately decreed: demote Shen and Gui by two ranks each; as for Shi Dan, for failing to fulfill his duties, strip him of the seals of Grand Minister of Works and Marquis of Gaole, dismiss him from office, and send him home to retire.
The idiom "deep thought and far-reaching consideration" means thinking deeply and planning ahead. It later evolved into "deep planning and far-reaching consideration" and "deep thought and extreme consideration," retaining the same meaning.
Source: *Book of Han*, "Biography of Shi Dan"
Meaning of the Idiom: Later, the Chinese idiom "深思远虑" came to describe thinking deeply and planning ahead.