Liu Xin's ancestor, Liu Jiao, the Prince of Chu, was Emperor Gaozu of Han's half-brother, who loved reading from childhood and especially enjoyed studying the *Book of Songs*.
Liu Xin's father, Liu Xiang, was a renowned classical scholar, bibliographer, and literary figure who specialized in the *Guliang Commentary on the Spring and Autumn Annals*.
During the Heping era of Emperor Cheng's reign, Liu Xin was summoned by imperial decree to join his father in overseeing the collation and editing of the precious books and archives stored in the palace.
While collating ancient texts, the scholar Liu Xin discovered the old-script version of *Zuo's Commentary on the Spring and Autumn Annals*, declaring it far superior to the existing *Guliang's Commentary* and *Gongyang's Commentary*.
Liu Xiang disagreed with his son's view, saying, "The *Guliang Commentary* focuses on explaining ancient terms and institutions to resolve later scholars' doubts about forgotten systems; the *Gongyang Commentary* emphasizes the subtle, profound principles that honor the king in the *Spring and Autumn Annals*. These two commentaries are the great pillars of the *Annals*. As for the *Zuo Commentary*, its strength lies in narrating historical events in full detail, but recounting facts can never compare to clarifying the sage Confucius's grand purpose in compiling the *Annals*!"
Liu Xin countered, "The *Analects* records the sage's words: 'Clever speech, an ingratiating manner, and excessive respect—Zuo Qiuming found these shameful, and I, Confucius, find them shameful too. Hiding resentment while pretending to be friendly—Zuo Qiuming found this shameful, and I find it shameful too.' This proves Zuo Qiuming had direct contact with the sage, while Guliang Chi and Gongyang Gao lived after Confucius's seventy-two disciples. Zuo Qiuming witnessed events firsthand; Guliang and Gongyang relied on hearsay. Thus, the *Guliang Zhuan* and *Gongyang Zhuan* cannot be compared to the *Zuo Zhuan* in elucidating the sage's thoughts. The foremost contributor to interpreting the classics must be Zuo Qiuming."
Liu Xiang had no words to reply.
Prime Minister Zhai Fangjin, a devoted scholar of the Zuo Commentary, joined Grand Marshal Wang Mang in recommending Liu Xin to the newly enthroned Emperor Ai of Han, praising his exceptional talent and learning. Liu Xin was thus promoted to Cavalry Commandant, Imperial Carriage Attendant, and Grand Master of Splendid Happiness, becoming a trusted advisor close to the emperor.
The scholar Liu Xin proposed elevating the status of the *Zuo Commentary on the Spring and Autumn Annals* by establishing an official chair for its study. Emperor Ai summoned the Five Classics doctors to debate the matter. During the discussion, Liu Xin spoke eloquently, delving into profound subtleties, but the senior doctors, having colluded among themselves, remained silent, offering no opinion either for or against.
Liu Xin later wrote a long letter to the Grand Court Academician, saying, "Your subordinate scholars stubbornly cling to outdated fragments, driven by fear of losing their academic standing, lacking any public spirit to follow what is right. Worse still, they harbor jealousy, blindly echoing each other regardless of right or wrong. If this continues, what will become of us!"
Unfortunately, the scholars of the time were too conservative, and no one agreed with Liu Xin's views. It was not until the end of the Western Han Dynasty, when Liu Xin was honored as "National Teacher," that the *Zuo Commentary* was finally established as an official text. "Baocan Shouque" (also written as "Baocan Shouque" or "Baocan Shouque") refers to being ideologically conservative and unwilling to accept new things.
Source: *Book of Han*, "Biography of Liu Xin"
Meaning of the Idiom: Later, the Chinese idiom "保残守缺" came to describe how being ideologically conservative and unwilling to accept new things.