The idea of immortality permeates the whole of Taoist teachings. Its conscious attainment is one of the fruits of alchemical life with which the more profound teachings of Taoism are concerned. It is realized through perfect union with the Tao.
The aim of Taoist teachings is to free man from all that which is transient, enabling him to use and enjoy all things to the fullest possible extent by assigning them to their proper place in life.
Numerous methods are given in Taoist writings for the realization of immortality, foremost among which is a system of mental and spiritual practices.
According to the levels of spiritual attainment, there are five classes of immortals in Taoist Alchemy:
Ghost Immortals remain ghosts, but they are different from ordinary ghosts in that they are able to communicate spiritually and subsist for a long time.
Human Immortals remain human, but though they eat, drink, and dress like people, yet they can avoid the calamities of aging, sickness and death.
Earth Immortals remain on the earth, but they are not affected by cold or heat, hunger or thirst. Thought they cannot project their spirits, yet they can avoid the bother of food, clothing and shelter.
Spiritual Immortals are capable of supernatural power and transformations; coming and going at will, they can shed physical shell to attain an ethereal independence. They can dissolve into energy or solidify into form.
Celestial Immortals go even further in their work than spiritual immortality. They go beyond our human world, to another world that cannot be imagined by the ordinary intellect.