Ch'ang-sheng pu-ssu (Taoism)

(i) School of the outer elixir: physical immortality. As the result of following various prescribed practices, in particular swallowing certain substances, the individual attempts to prolong indefinitely his life in the physical body. He may appear to die but his coffin will be found to be empty; or he may ascend to heaven without even the appearance of dying.

(ii) School of the inner elixir: spiritual immortality. By following esoteric practices the individual becomes one with the absolute or highest principle. There is freedom from life and death as the distinctions between life and death, male and female, dissolve away, yin and yang combine, and one is no longer limited by time or space.

Although physical and spiritual immortality are considered separately, the one is often used as a metaphor for the other, so that, for example, what may seem to be a description of the chemical process of manufacturing a pill of physical immortality may be a pictorial representation of the development of inner gold.