Library

[Diagram of the Prior Heaven]
To speak of medicine, one must first study the *I Ching* (Book of Changes). This does not mean studying the drawing of hexagrams, but rather understanding the changing lines (Yao). If one examines the mind, are there actually drawn hexagrams? Are there actually changing lines? It is merely the undifferentiated unity of primal principle (Yuanli) and primal qi (Yuanqi). The creation of heaven, earth, humans, and all things is governed by this creative force. Those who understand how to nourish life will naturally restrain anger and curb desires, leading to the harmonious interaction of water and fire (Heart-Kidney intersection). Those who seek to benefit others will, upon understanding this, naturally distinguish substances and arrange them appropriately, thereby recovering from severe and sudden illnesses. Placing the diagram at the beginning of the scroll facilitates reverence for those who cannot read; it is extremely simple and easy, yet interesting to contemplate. How dare I claim to exert effort only on the mind of Fuxi, in order to secretly appropriate the subtle meanings of Xuanyuan (Yellow Emperor) and Qibo? This is the explanation.

[Diagram]
All human diseases arise from the failure of water and fire to interact. Therefore, the post-heaven Kan (Water) and Li (Fire) trigrams are used to continue the discussion. Blood belongs to Water, and Qi belongs to Fire; blood is Yin, and Qi is Yang. The Li trigram is hollow in the center, harboring true Yin; the Kan trigram is solid in the center, housing true Yang. Understanding the mechanism of Yin-Yang deficiency and excess means that half of medical theory has been comprehended.

[Diagram]
There are twelve primary meridians (Jing) and fifteen collateral vessels (Luo), totaling twenty-seven. Qi and Blood circulate through them without rest. Thus, the ascent and descent of Yin and Yang over a year converge at the Beginning of Spring (Lichun); the transition between day and night within a day converges at the Yin hour. The circulation of Ying (Nutritive) Qi and Wei (Defensive) Qi corresponds above to the celestial degrees and below to the terrestrial regions. Heaven has stellar degrees; Earth has river systems; Humans have meridians. "Xiu" refers to the Twenty-Eight Mansions; "Du" refers to the 365 degrees of the celestial sphere. "Jing Shui" (Meridian Waters) refers to the Sea Water, Qing Water, Wei Water, Hu Water, Mian Water, Ru Water, Jiang Water, Huai Water, Luo Water, He Water, Zhang Water, and Ji Water. They are named "Meridian Waters" because they correspond internally to the human meridians. "Jing Mai" (Primary Meridians) refers to the six Yin and six Yang meridians of the hands and feet. These are discussed because internal and external aspects correlate, and human Qi responds to them. Internally, the Foot Yangming Stomach Meridian corresponds externally to Sea Water; the Foot Taiyang Bladder Meridian to Qing Water; the Foot Shaoyang Gallbladder Meridian to Wei Water; the Foot Taiyin Spleen Meridian to Hu Water; the Foot Jueyin Liver Meridian to Mian Water; the Foot Shaoyin Kidney Meridian to Ru Water; the Hand Yangming Large Intestine Meridian to Jiang Water; the Hand Taiyang Small Intestine Meridian to Huai Water; the Hand Shaoyang Sanjiao Meridian to Luo Water; the Hand Taiyin Lung Meridian to He Water; the Hand Jueyin Pericardium Meridian to Zhang Water; and the Hand Shaoyin Heart Meridian to Ji Water. There is mutual transmission between the interior and exterior. Wei Qi guards the exterior, filling the skin and hair; Ying Blood nourishes the interior, managing the meridians. Circulating through the entire body without gap, corresponding to the hundred strokes of the clepsydra (water clock) without deviation, with 13,500 breaths in 101 nights, this is the normal state of a healthy person. To examine Yin and Yang and determine life and death: although the flow of meridians is like a circle without beginning or end, can it escape the three positions (Cun, Guan, Chi) of pulse diagnosis? As for herbs, insects, and animals, they all receive Qi first. Therefore, even dried and aged materials can regulate Zang-Fu organs and treat diseases, as their Qi is similar. Students should contemplate this.