The Huangting Jing, the Yellow Court Classic, exists in inner and outer recensions dating from around the second to fourth centuries and is the foundational text of Taoist visualisation. It maps the body as an inhabited administrative landscape: each of the five viscera and many other locations houses a resident spirit with a proper name, a specific colour, a costume and a size, and the practitioner learns to visualise these officials clearly and hold them in place, because a spirit that abandons its post produces illness and eventually death. The verse is dense and deliberately technical, and it is essentially unreadable without oral instruction, which is precisely how it functioned. It has a second life in Chinese art history: Wang Xizhi, the fourth-century master regarded as the greatest of all Chinese calligraphers, transcribed it, and the Huangting Jing tie is among the most copied models in the calligraphic tradition — so generations of Chinese schoolchildren have written out a Taoist meditation manual while learning to write.