Daoism in the Sui Dynasty

  Although the Sui Dynasty lasted for less than 40 years, Taoism still achieved a certain degree of development during the short reign of this dynasty. The Sui Dynasty implemented a policy of compatible Buddhism and Taoism. Although Buddhism was given priority, Taoism was also highly valued. For example, Emperor Wen of the Sui Dynasty named his founding reign title "Kaihuang", which was derived from Taoist scriptures.

  During the Sui Dynasty, both the number of Taoist temples and Taoist priests increased. For instance, Emperor Wen of the Sui Dynasty built a large number of Taoist temples and ordained Taoist priests to support the development of Taoism. Later, Emperor Yang of the Sui Dynasty was even more devout in advocating Taoism; he alone had ten Taoist temples built for Taoism in Chang'an.

  During this period, the Shangqing scriptures and methods of the Maoshan School, which had been spread to the north, were incorporated into scripture systems such as the Lingbao and Sanhuang, and merged with the Louguan Taoism in the north. In terms of cultivation techniques, the most prominent development was the rise of "Neidan" (inner alchemy). According to Records of Luofu Mountain, the Taoist priest Su Xuanlang once lived in seclusion in Juqu Mountain to study Taoism and obtained the secret teachings of Siming Zhenjun. During the Kaihuang period, he went to Qingxia Valley in Luofu Mountain to practice alchemy, calling himself "Qingxiazi". He wrote works such as Records of the Stone Wall of Taiqing and later On the Essence of Taoism, which expounded the methods of Neidan cultivation. From then on, Taoism began to have the theory of Neidan. Su Xuanlang used Waidan (outer alchemy) terms to explain Neidan and advocated "the simultaneous cultivation of nature and life" as the core of Neidan cultivation. After practicing inner vision for nine years, Su achieved enlightenment and ascended to immortality. Judging from his words and deeds, he can be said to be a theorist, practitioner, and propagandist of Neidan. The Neidan Taoism advocated by Su Xuanlang in the Sui Dynasty developed rapidly and became popular in the Tang Dynasty, exerting a profound influence on the development of Taoism in later generations.