According to the *Taishang Yinshu* (Hidden Book of the Supreme High): The methods originally have no fixed form; their principle returns to nature. The mind becomes chaotic due to external circumstances, yet the method originates from the mind itself. The intention behind establishing these methods is to remedy what has already been lost and to prevent what has not yet emerged. Therefore, there are "three thousand six hundred methods" and "dozens of schools for nourishing life." The "three thousand six hundred methods" refer to a period of ten years; the "dozens of schools for nourishing life" refer to the numerology of Heaven One Earth Two, Heaven Three Earth Four, Heaven Five Earth Six, Heaven Seven Earth Eight, Heaven Nine Earth Ten. One, three, five, seven, nine are the Yang numbers of the Five Elements (Wuxing); two, four, six, eight, ten are the Yin numbers of the Five Elements. The Great Dao divides into two Qi (vital energies), and the two Qi split into the Five Elements. Macroscopically, they manifest as Heaven and Earth; brightly, as the Sun and Moon; spiritually, as humans. None do not receive the two Qi to generate the Five Elements, nor operate the Five Elements to penetrate the Three Powers (Heaven, Earth, and Humanity).

The *Xishan Ji* (Record of Mount Xi) states: Hua Tuo observed the performance of the Five Animal Frolics (a Daoyin exercise imitating five animals) and created Daoyin (guiding and pulling exercises), believing that long-term ease leads to stagnant Qi and coagulated blood. Thus, by bending the body and laboring the form, one can make Ying (Nutritive) and Wei (Defensive) Qi flow smoothly. Later generations named this "Banyun" (general transport). To seek transcendence through this is an error. In the past, Chen Yi left his daughter on the road; after starving for a long time, she learned the breathing technique of turtles (Gui Zhi Tu Na) and survived for a year without food. Later generations named this "Fuqi" (swallowing Qi). To seek elixirs through this is an error. Zhang Shao examined how the Five Flavors (sour, bitter, sweet, pungent, salty) disrupt the body's true fluids, causing one Zang organ to be strong while another is weak, one Qi prosperous while another deficient. Thus, he advocated abandoning the five flavors and eating plain and bland food. Later generations named this "Xiuliang" (stopping grain consumption/Bigu), which is also an error. Liu Dong understood True Yang and True Yin; when in excess, he guided its offspring (based on the generating cycle of Wuxing); when deficient, he subdued its conqueror (based on the controlling cycle of Wuxing), applying tonification and sedation. Later generations adopted the practice of collecting the essence of the sun and moon and drawing the righteous Qi of heaven and earth, which is an error.

In the past, Guangchengzi taught the Yellow Emperor the art of sexual intercourse (Fangzhong Shu), fearing the loss of true Qi and the detriment to proper cultivation. He only advised resisting desires and avoiding tempting situations, not advocating that sexual techniques yield merit by draining women's Qi. Later generations believed it was "humans supplementing humans," extracting Qi to return Essence, harming others and themselves, yet hoping for longevity. This is an error.

Guangchengzi taught the Yellow Emperor to cultivate according to the methods, but no results were seen for a long time. On Kongtong Mountain, taking internal affairs (Neidan/Internal Alchemy) as the rule, he refined external elixirs (Waidan) to repair damage accumulated from long-term deficiency. Later generations used lifeless minerals and metals, refining them in smoke and flames, separating the embryo to reveal treasures, desiring to ingest them to seek ascension or immortality and longevity. This is an error.

Bian Que interpreted the *Lingshu* (Spiritual Pivot), advising to draw clear Qi through the nose and exhale turbid Qi through the mouth, with twenty-four breaths constituting one cycle. Using two fires to refine True Lead (Zhen Qian), like playing with flower stamens, is called "Yang Embryo"; refining True Mercury (Zhen Gong), like holding a lotus, is called "Yin Embryo." The embryo forms when breath stops; when breath stops, spirit remains. This can preserve the form in the world, accumulating merit to become sage-like and transcendent. Later generations adopted the method of inhaling much and exhaling little, seeking to gather Qi into an embryo, using breath retention as the method. This is an error. The *Jiuxian Jing* (Scripture of the Nine Immortals) says: For severe illness, use Fire; for mild illness, use Water. Using Fire means absorbing Qi so it rises back into the body, allowing True Qi to pervade the Four Extremities (the whole body), so that Yin ghosts and evil demons dare not approach. Using Water means absorbing Qi so it rises back into the body, with Qi penetrating water like a gushing spring; in meditation, sending intent to the diseased area allows Qi and Blood to flow freely, naturally removing obstruction. Later generations sat alone and held their breath, using the tongue as a windlass, rotating left and right to collect residual saliva, rinsing and swallowing it, then letting it pass through the intestines and stomach outwards, calling this "irrigating to grow the Yellow Sprout," desiring to create the Great Medicine. This is an error. The *Tongxuan Zhenjing* (Scripture of the True Mystery) says: Guard the Way of Non-action, obtain the Principle of Nature. Be clear and not turbid, still before moving, shift the spirit to the realm of Formlessness and Soundlessness, preserve the form on the path of Benevolence and Longevity. When no thought arises, all delusions cease; one achieves longevity and lives at ease. Later generations failed to understand the need to choose silence and cut off traces, silently forgetting schemes, resulting in no effect after a full year. This is an error. The *Lingshi Neiguan Jing* (Scripture of Inner Observation in the Spiritual Chamber) says: External environments do not enter, internal environments do not exit; spirit and consciousness guard themselves, closing the eyes to look inward. Descend the Sovereign Fire to the Lower Dantian, spread Yellow Cloud over the Four Extremities, chariots and carriages appear in succession, deriving the joy of the pot within (a metaphor for inner alchemical space). Later generations became like dead wood and ashes, strictly guarding empty void, falling into drowsy silence, allowing Yin spirits to exit through the Heavenly Gate, ultimately only able to reincarnate and take residence. This is an error.

There are also practices such as opening the crown, shrinking the turtle, dwelling in mountains to recognize nature, refining and reading, giving alms, and making offerings. These are not only useless but harmful. They are small methods and heterodox paths self-created by ignorant people with little knowledge, passed down mutually, confusing later generations, causing the Great Dao to become increasingly distant. They do not know to look up and observe down, silently conforming to the appropriateness of Heaven and Earth's Yin and Yang ascending and descending, and the logic of the Sun and Moon's soul and spirit往来 (coming and going). When one Qi first floats, one recognizes one's own Yin and Yang; once the Five Elements are divided, one intersects one's own Water and Fire. There is Water within Fire, and Fire within Water. Fire bears Yin above, appearing vague and indistinct, this substance is True One Water; Water embraces Yang below, appearing dark and obscure, this vitality is Righteous Yang Qi. When the two Qi interact and couple, they form Internal Medicine and nurture the Golden Elixir, becoming an immortal among men on land.