Supreme Scripture of Inner Alchemy 太上长文大洞灵宝幽玄上品妙经

Referred to as The Long Text of the Great Cavern Scripture for short, its author is unknown.

Judging from its content, it was presumably composed during the late Tang Dynasty and the Five Dynasties period.

Consisting of one scroll, it is included in the Tai Xuan Section within the Daoist Canon (The Daozang).

Supreme Scripture of Inner Alchemy

As a classic of Neidan (Internal Alchemy), the scripture is divided into nineteen chapters. It states that human form, spirit, essence, and blood are all generated by the Qi transformation of heaven and earth: "Spirit is the function of yin and yang Qi; form is the abode of spirit and Qi; yin-yang soul and ethereal soul are the spirits of essence and blood." Thus, only by preserving spirit, nourishing Qi, consolidating blood, and refining essence can one attain longevity.

The method of refining Qi and nourishing spirit is called the "Method of True Unity." The scripture explains: "Simply refine the Qi in the Dantian within the body to make it strong, and cultivate the natural spirit to make it complete. Throughout the twelve two-hour periods of the day, guard the innocent Qi and guide it into the Dantian Palace—with no random thoughts in the mind, no distracting intentions outwardly, neither going out nor coming in, no coming nor going. When spirit is stabilized, peace will naturally follow; this is the Method of True Unity."

It further discusses the path of "Huan Dan" (Returning Elixir), declaring: "Guiding one’s original true Qi from below back upward is called 'yin returning to yang'; guiding the single primal true Qi from above back downward is called 'yang returning to yin.' When the six yins and six yangs converge in the Huangting (Yellow Court, a key energy center in the body) and return to the Dantian, both spirit and Qi will be abundant—thus forming the Returning Elixir." Its teachings are relatively concise and straightforward.