\r先天图\pS92a1.bmp\r
学《易》而后可以言医，非学乎画也，学乎爻也。试观之心，果有画乎？果有爻乎？元理元气浑合无间
而已。生天生地，生人生物，皆由此造化以为之主也。颐生者知此，则自然惩忿窒欲而水火交泰。济人者知此，
则自然辨物居方而沉 顿复。圈之于首，以便不识字者开卷肃然，至简至易而玩之有趣耳。敢曰且于羲皇心地
上着力，以窃轩岐之微意哉！是为说。
\r图\pS92a2.bmp\r
人之百病，皆由水火不交，故以后天坎离继之。血属水，气属火，血阴而气阳也。离中虚，真阴存焉；
坎中满，真阳寓焉。阴阳虚实之机，医道思过半矣。
\r图\pS92a3.bmp\r
经十二，络十五，凡二十七，气血相贯，无有休息。故一岁阴阳升降，会于立春；一日阴阳晓昏，会于
寅时。荣卫循环，上应天之度数，下应地之分野。天有宿度，地有经水，人有经脉。宿谓二十八宿，度谓天之三
百六十五度也。经水者，谓海水、清水、渭水、湖水、沔水、汝水、江水、淮水、漯水、河水、漳水、济水也，
以其内合经脉，故名之曰经水焉。经脉者，谓手足三阴三阳之脉，所以言者，以内外参合，人气应之，故言及
也。内足阳明，外合海水；内
足太阳，外合清水；内足少阳，外合渭水；内足太阴，外合湖水；内足厥阴，外合沔水；内足少阴，外合汝水；
内手阳明，外合江水；内手太阳，外合淮水；内手少阳，外合漯水；内手太阴，外合河水；内手心主，外合漳
水；内手少阴，外合济水，内外输应。气卫于外，以充皮肤；血荣于中，以营经络。周一体而无间，应漏水百
刻而不违，一百一夜，一万三千五百息，乃平人之常也。察阴阳，决生死，虽经络流注，如环之无端，岂能逃
于脉之三部耶？至于草木昆虫，尽皆得气之先，所以虽干枯陈朽，亦可以调脏腑而治疾病，其气同也，学人玩
之。
【先天图】
学习《易经》之后才可以谈论医学，学的不是卦象的画法，而是爻的变化。试着观察内心，真的有画出来的卦象吗？真的有变化的爻吗？不过是元理与元气浑然一体、没有间隙罢了。生成天、地、人、万物，都是由此造化作为主宰。懂得养生的人知晓这个道理，自然会克制愤怒、遏制欲望，使心肾相交（水火既济）。救治他人的人知晓这个道理，自然会辨别物性、居处得当，从而在沉疴顿疾中恢复生机。将图圈画在卷首，是为了方便不识字的人翻开书卷时能保持肃敬之心，这至简至易，玩味起来却饶有趣味。岂敢说是只在伏羲氏的心地上用力，以窃取轩辕、岐伯的深意呢！这就是所说的道理。
【图】
人的各种疾病，都是由水火不能相交引起的，所以用后天的坎卦和离卦来接续说明。血属于水，气属于火，血为阴而气为阳。离卦中间是虚的，真阴存于其中；坎卦中间是实的，真阳寓于其中。阴阳虚实变化的机理，医道思虑到这里就已经成功了一半。
【图】
经脉十二条，络脉十五条，总共二十七条，气血相互贯通，没有休息的时候。所以一年中阴阳的升降，汇聚于立春时节；一天中阴阳的明暗交替，汇聚于寅时。营气和卫气的循环，上应合天的度数，下应合地的分野。天有星宿度数，地有河流经水，人有经脉。所谓“宿”，指的是二十八宿；所谓“度”，指的是天球的三百六十五度。所谓“经水”，指的是海水、清水、渭水、湖水、沔水、汝水、江水、淮水、漯水、河水、漳水、济水，因为这些河流内部对应着人体的经脉，所以称之为经水。所谓“经脉”，指的是手三阴三阳和足三阴三阳的脉络，之所以要提及它们，是因为内外参合，人气与之相应，所以谈到这些。内属足阳明胃经，外合海水；内属足太阳膀胱经，外合清水；内属足少阳胆经，外合渭水；内属足太阴脾经，外合湖水；内属足厥阴肝经，外合沔水；内属足少阴肾经，外合汝水；内属手阳明大肠经，外合江水；内属手太阳小肠经，外合淮水；内属手少阳三焦经，外合漯水；内属手太阴肺经，外合河水；内属手厥阴心包经，外合漳水；内属手少阴心经，外合济水，内外输注相应。气护卫在体表，以充实皮肤；血荣养在体内，以滋养经络。周流全身而没有间隙，应合漏刻计时的一百刻而不违背，一百零一夜，一万三千五百次呼吸，这是健康常人的常态。察验阴阳，决断生死，虽然经络流注像圆环一样没有开端和终结，难道能逃脱于寸关尺三部脉诊之外吗？至于草木昆虫，都最先得到天地之气，所以即使是干枯陈旧的药材，也可以调理脏腑而治疗疾病，因为它们的性质是相通的，学习者应当仔细玩味。
[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.