The Xiang'er was likely written between 190 and 220 CE, a time when the Celestial Masters controlled a theocratic state in Sichuan.
The text available to us today was discovered in the Buddhist Mogao caves at Dunhuang in the early 20th century and was part of the trove that traveled to London along with Aurel Stein.
The Xiang'er reveals a great deal about early Celestial Master thought and practice.
In terms of individual advice, the Xiang'er, like the rest of Daoism, discusses ways in which a person could gain immortality.
In order to attain immortality, a person had to preserve and nourish these internal spirits.