不欺暗室 — “Not deceive oneself in a hidden room”

Qu Boyu, whose given name was Yuan and courtesy name Boyu, was from the State of Pu during the Spring and Autumn period, living around the same time as Confucius. He was a renowned virtuous Grand Master during the reign of Duke Ling of Wey, and a man of exceptional morality and conduct. Historically, Qu Boyu has been regarded as the quintessential gentleman of Wey, embodying the saying, "Wey abounds with gentlemen."

Qu Boyu was highly virtuous, and people held him in great esteem. One night, Duke Ling of Wey and his wife Nanzi were sitting in the palace. They first heard the rattling of a carriage, but the sound ceased upon reaching the palace gate, only to resume a moment later. Duke Ling asked his wife, "Do you know who just passed by?" His wife replied, "It must be Qu Boyu." The Duke asked, "How do you know?" Nanzi explained, "A gentleman is very meticulous about the details of his life. When the carriage reached the palace gate and the sound ceased, it meant the owner had instructed the driver to dismount and guide the carriage slowly by hand, fearing the noise would disturb Your Grace. A loyal minister and a filial son would not make grand vows in public, nor would they alter their principles simply because no one can see them in the dark. Qu Boyu is an upright Grand Master of our State of Wey, benevolent and wise, faithfully performing his duties to the country. He would not forget propriety just because it is nighttime and no one is watching. That is why I believe it was him." Duke Ling sent someone to check, and indeed, it was Qu Boyu.

Duke Ling jokingly told his wife, "It wasn't Qu Boyu." Upon hearing this, his wife immediately offered him wine and congratulations. Duke Ling asked, "Why are you congratulating me?" His wife said, "Initially, I thought Qu Boyu was the only virtuous person in Wey. Now I know there is another equally virtuous person in our state, which means we have two worthy ministers. A state with many worthy ministers is a blessing; how could I not congratulate you?" Duke Ling said, "Well said!" and then revealed the truth.

Qu Boyu assisted Duke Ling of Wey in governing the state, making its army strong and its people prosperous, thus transforming it into a powerful state during the Spring and Autumn period. Zhao Jianzi, a general from the State of Jin, initially intended to invade Wey and sent someone to scout. Upon his return, the scout told Zhao Jianzi, "With Qu Boyu in power in Wey, we would surely suffer defeat if we rashly attacked." Zhao Jianzi immediately canceled his plan to attack Wey.

Qu Boyu was humble and prudent, often reflecting on himself, saying, "At fifty, I realized the wrongs of my forty-nine years." He also constantly urged himself forward. The "Zhuangzi: Zexiang" chapter records: "Qu Boyu, at sixty, transformed sixty times." This meant that even at sixty, he could still renew himself daily, adapting to changes with the times. Such a virtuous person always had clear demands for his own morals and conduct, and consistently adhered to these requirements diligently.