Internal alchemy

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. Also known as Jindan ("golden elixir"), inner alchemy combines theories derived from external alchemy (waidan), correlative cosmology (including the Five Phases), the emblems of the Yijing, and medical theory, with techniques of Daoist meditation, daoyin gymnastics, and sexual hygiene.

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.

Neidan is part of the Chinese alchemical meditative tradition that is said to have been separated into internal and external (Waidan) at some point during the Tang dynasty. The Cantong qi (The Kinship of the Three) is the earliest known book on theoretical alchemy in China; it was written by the alchemist Wei Boyang in 142 AD. This text influenced the formation of Neidan, whose earliest existing texts date from the first half of the 8th century. The authors of several Neidan articles refer to their teachings as the Way of the Golden Elixir (jindan zhi dao). The majority of Chinese alchemical sources is found in the Daozang (Taoist Canon), the largest collection of Taoist texts.

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