Neidan
Neidan, or internal alchemy (simplified Chinese: 內丹术; traditional Chinese: 內丹術; pinyin: nèidān shù), is an array of esoteric doctrines and physical, mental, and spiritual practices that Taoist initiates use to prolong life and create an immortal spiritual body that would survive after death (Skar and Pregadio 2000, 464). Also known as Jindan (金丹 "golden elixir"), inner alchemy combines theories derived from external alchemy (waidan 外丹), correlative cosmology (including the Five Phases), the emblems of the Yijing, and medical theory, with techniques of Daoist meditation, daoyin gymnastics, and sexual hygiene (Baldrian-Hussein 2008, 762).
In Neidan the human body becomes a cauldron (or "ding") in which the Three Treasures of Jing ("Essence"), Qi ("Breath") and Shen ("Spirit") are cultivated for the purpose of improving physical, emotional and mental health, and ultimately returning to the primordial unity of the Tao, i.e., becoming an Immortal. It is believed the Xiuzhen Tu is such a cultivation map. In China, it is an important form of practice for most schools of Taoism.
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