Honoring Confucianism alone
In the first year of Jianyuan, Dong Zhongshu advised that "all who are not of the six arts and the way of Confucius should have their paths cut off." Emperor Wu adopted it, set up erudites of the Five Classics, and founded the Imperial Academy — mastery of the classics became the road to office, and studying the Confucian canon the path to becoming an official. The algorithmic effect of this decision ran for two thousand years: the empire mass-produced bureaucrats through one fixed classical curriculum, and unity of thought no longer relied on bans but on examinations.
The self-reproach at Luntai
In his later years, the witchcraft scandal drove Emperor Wu to force the death of his heir Liu Ju, and the pursuit of immortality and endless campaigns drained the state, so that "the realm was emptied, its households halved." In 89 BC, when Sang Hongyang and others proposed garrison farming at Luntai to keep managing the Western Regions, Emperor Wu issued an edict rejecting it, regretting that "since I took the throne, what I have done has been wild and perverse, bringing sorrow to the realm," and declared a halt to war to nurture the people. An emperor publicly admitting fault — the first such case in documented history — and this braking is why the Han avoided repeating Qin’s collapse.