Zhang Daoling
Kou apparently began his career as a Taoist physician and hygienist. But in 415 he had a vision: a spirit appeared before him and told him that since the death of Zhang Daoling, the great founder of the Way of the Celestial Master ("Tradition of the Celestial Master of the Mighty Commonwealth of Orthodox Oneness") sect of Taoism, the sect had been corrupted by false doctrines. Kou was awarded Zhang Daoling's old title of "tianshi" ("celestial master") and was charged in the vision with eliminating excesses in Taoist rituals. Accordingly, Kou began to attempt to curb the orgiastic practices and mercenary spirit that had become associated with Taoist rites and to place greater emphasis on hygienic ritual and good works.