大哉医乎，其来远矣！粤自混沌既判，洪
荒始分，阳之轻清者，以气而上浮为天；阴之重浊者，以形而下凝为地。天隆然而位乎上，地 然而位乎下。
于是阳之精者为日，东升而西坠；阴之精者为月，夜见而昼隐。两仪立矣，二曜行焉。于是玄气凝空，水
始生也；赤气炫空，火始生也；苍气浮空，木始生也；素气横空，金始生也； 气际空，土始生也。五行备，
万物生，三才之道着矣。是以惟人之生，得天地之正气，头圆象天，足方象地，天有阴阳，人有气血；天有五行，
人有五脏。盖葛天氏之民，巢居穴处，茹毛饮血，动作以避其寒，阴居以避其暑，大朴未开，何病之有？迨夫伏羲
氏占天望气而画卦，后世有《天元玉册》，目为伏羲之书者，乃鬼臾区十世口诵而传之也。神农氏尝百草，一日
而七十毒，厥后本草兴焉。黄帝垂衣裳而天下治，与岐伯天师更相问难，上推天文，下穷地理，中极民瘼，
《内经》自此而作矣，此经既作，民之有疾，必假砭针以治其外，汤液以疗其内，厥后大朴散而风化开，民务
繁而欲心纵，灾 多端，非大毒、小毒、常毒、无毒之药，弗能蠲矣。医之大原，《素问》一书而已矣。二十四
卷，八十一篇，其间推原运气之加临，阐明经络之标本，论病必归其要，处治各得其宜，井然而有条，粲然而
不紊，若《天元纪大论》、《六元正纪大论》、《五常政大论》、《气交变大论》、《至真要大论》数篇，乃至
精至微之妙道，诚万世释缚脱难，全真导气，拯黎元于仁寿，济羸劣以获安者之大典也。轩岐以下，代不乏人，
扁鹊得其一二，演而述《难经》，皇甫士安次而为《甲乙》，杨上善纂而为《太素》，如全元起之解，启玄子
之注，所谓源洁则流清，表端则形正，历代之明医也。独有汉长沙太守张仲景者，揣本求源，探微赜隐，取其
大小奇偶之制，定君臣佐使之法而作医方，表里虚实，真千载不传之秘，乃大贤亚圣之资，有继往开来之功也。
汉唐以下，学人岂不欲涉其渊微之旨，矧《内经》之理深幽，无径可入，如巢元方之作《病源》书，孙思邈之
作《千金方》，辞益繁而理愈昧，方弥广而法失真，《内经》之书，施用者鲜矣。及朱奉议宗长沙太守之论，编
《南阳活人》之书，仲景训阴阳为表里，奉议解阴阳为寒热，差之毫厘，谬以千里，其活人也固多，其死人也
不寡矣。幸而守真刘子《要旨论》、《原病式》二书既作，则《内经》之理，昭如日月之明；《直格》书、《宣
明论》二书既作，则长沙之法，约如枢机之要。如改桂枝麻黄各半汤为双解散，变十枣汤为三花神佑丸，其有
功于圣门也不浅矣。同时有张子和者，出明《内经》之大道，续河间之正源，与麻知几讲学而作《儒门事亲》之
书，乃曰∶吐中有汗，泻中有补，圣人止有三法，无第四法。乃不易之确论，至精之格言，于是有刘、张之派矣。
若东垣老人，明《素问》之理，宗仲景之法，作济拔萃十书以传于世，明脉取权衡规矩，用药体升降浮沉，是以
有王道、霸道譬焉。至于丹溪朱氏，伤寒内伤杂病，无不精研，痰火奥义，犹其独得，宋太史濂谓其集医家之
大成，诚哉是言也！迨及我朝修《大观本草》、制《铜人俞穴针灸经》、御赐《医方》等书，设太医以辅圣
躬，立良医以佐王府，惠民药局以济民间天扎，其仁天下之心，宛与轩岐一揆而远迈汉唐。是以名医迭出，如
陶节庵之伤寒，发仲景之所未发；薛己之外科，补东垣之未备；葛可久之内伤、钱瑛之小儿，亦无忝于丹溪。
昭代作人之功，其盛矣乎！后学知道统之自，则门径不差，而医道亦可近矣。故曰∶知其要者，一言而终。
医学之道真是伟大啊，它的起源非常久远！自从混沌分开，洪荒时代开始，阳气中轻清的部分，凭借气的性质向上漂浮而成为天；阴气中重浊的部分，凭借形的性质向下凝结而成为地。天高高在上位于上方，地安稳在下位于下方。
于是，阳气中的精华部分化为太阳，从东方升起而在西方落下；阴气中的精华部分化为月亮，夜间出现而白天隐没。天地两仪确立，日月二曜运行。于是玄色的气凝聚在天空中，水就开始产生；赤色的气闪耀在天空中，火就开始产生；苍色的气浮现在天空中，木就开始产生；素色的气横亘在天空中，金就开始产生；黄色的气弥漫在天空中，土就开始产生。五行具备，万物生长，天、地、人三才的道理就显现了。因此，人的诞生，得自天地的正气，头圆象征天，脚方象征地，天有阴阳，人有气血；天有五行，人有五脏。
大概在葛天氏那个时代，百姓居住在巢穴或洞穴中，吃带毛的肉、喝血，通过活动来躲避寒冷，居住在阴凉处来躲避暑热，质朴未开化，有什么疾病呢？等到伏羲氏观察天象、望气而画八卦，后世有《天元玉册》，被称为伏羲著作的，其实是鬼臾区十代人口传心授流传下来的。神农氏品尝百草，一天之内中毒七十次，此后本草学兴起。黄帝穿着衣裳治理天下，与岐伯天师互相问答探讨，上推天文，下穷地理，中极百姓疾苦，《内经》从此就产生了。这部经典既已作成，百姓有了疾病，必定借助砭石和针具来治疗体表的病，用汤液药剂来疗治体内的病，此后质朴散失而教化开启，百姓事务繁杂而欲望放纵，灾害多端，不是大毒、小毒、常毒、无毒的药物，不能消除病痛。医学的根本源头，不过是《素问》这一本书罢了。共二十四卷，八十一篇，其中推究运气加临的原理，阐明经络的标本关系，论述疾病必归其要领，处方治疗各得其适宜，井然有序，条理分明，像《天元纪大论》、《六元正纪大论》、《五常政大论》、《气交变大论》、《至真要大论》等篇章，乃至极其精微奥妙的道理，确实是千秋万代解开束缚、脱离灾难，保全真气、引导元气，拯救百姓于仁寿之境，帮助瘦弱者获得安宁的大典。
轩辕、岐伯之后，历代不乏人才，扁鹊得到其中的一二，演绎并撰写《难经》，皇甫士安整理编次为《甲乙经》，杨上善编纂为《太素》，如全元起的注解，王冰（启玄子）的注释，这就是所谓的源头清澈则水流清，树身端正则树形正，是历代著名的医生。只有汉代的长沙太守张仲景，探究根本寻求源头，探求幽深隐微的道理，选取大小奇偶的方制，确定君臣佐使的配伍法则而创制医方，表里虚实，真是千年不传的秘诀，是大贤亚圣的资质，有继承前代开创后世的功绩。
汉唐以后，求学的人难道不想涉猎其中深奥微妙的旨意吗？况且《内经》的道理深幽，没有直接的路径可入，比如巢元方编写《诸病源候论》，孙思邈编写《千金方》，言辞更加繁复而道理更加晦暗，方剂更加广泛而方法失去真谛，《内经》这本书，施用的时候很少了。到了朱奉议（朱肱）遵循长沙太守（张仲景）的理论，编写《南阳活人书》，张仲景将阴阳解释为表里，朱奉议将阴阳解释为寒热，差之毫厘，谬以千里，他救活的人固然多，死去的人也不少。幸好守真刘完素的《素问要旨论》、《原病式》两本书既已作成，那么《内经》的道理，就像日月一样光明；《直格》书、《宣明论》两本书既已作成，那么张仲景的方法，就像枢机一样简要关键。比如将桂枝麻黄各半汤改为双解散，变十枣汤为三花神佑丸，他对圣门的功劳也不浅了。同时代的张子和，阐发《内经》的大道，延续河间（刘完素）的正源，与麻知几讲学而编写《儒门事亲》一书，他说：吐法中有汗法的作用，泻法中有补法的作用，圣人只有这三种方法，没有第四种方法。这是不可改变的确实言论，极其精辟的格言，于是有了刘、张这一派。
至于东垣老人（李杲），阐明《素问》的道理，尊崇张仲景的方法，编写《脾胃论》等十种书流传于世，诊脉取法权衡规矩，用药体会升降浮沉的特性，因此有用王道、霸道来比喻的说法。至于丹溪朱震亨，伤寒、内伤、杂病，无不精心研究，痰火的深奥义理，更是他的独到之处，宋代的太史宋濂称他集医家之大成，这话说得确实对啊！等到本朝修订《大观本草》、制定《铜人俞穴针灸经》、皇帝赐给《医方》等书，设立太医辅助圣躬，建立良医辅佐王府，设立惠民药局救济民间的天折之人，其仁爱天下的心志，完全与轩辕、岐伯一致且远远超越汉唐。因此名医接连出现，如陶节庵研究伤寒，发掘出张仲景未曾阐发的内容；薛己研究外科，补充了李杲未曾完备的内容；葛可久的内伤、钱瑛的小儿科，也没有辜负丹溪的名声。昭代培养人才的功绩，真是兴盛啊！后学者知道了道统的来源，那么门径就不会出错，而医道也可以接近了。所以说：懂得要领的人，一句话就能终结（掌握全部）。
The Way of Medicine is truly great, and its origins are distant! Since chaos was divided and the primordial age began, the light and clear aspects of Yang Qi (vital energy) floated upward to form Heaven; the heavy and turbid aspects of Yin Qi condensed downward to form Earth. Heaven stands high above, and Earth rests firmly below.
Thus, the essence of Yang became the Sun, rising in the east and setting in the west; the essence of Yin became the Moon, appearing at night and hiding by day. The Two Powers (Heaven and Earth) were established, and the Two Luminaries (Sun and Moon) moved. Then, dark air condensed in the sky, and Water began to arise; red air shone in the sky, and Fire began to arise; green/cyan air floated in the sky, and Wood began to arise; white air stretched across the sky, and Metal began to arise; yellow air filled the sky, and Earth began to arise. With the Five Elements (Wood, Fire, Earth, Metal, Water) complete, all things were born, and the Dao of the Three Powers (Heaven, Earth, Humanity) became manifest. Therefore, human life derives from the upright Qi of Heaven and Earth: the head is round symbolizing Heaven, the feet are square symbolizing Earth; as Heaven has Yin and Yang, so do humans have Qi and Blood; as Heaven has the Five Elements, so do humans have the Five Zang Organs (Liver, Heart, Spleen, Lung, Kidney).
In the time of Ge Tian Shi, people lived in nests or caves, ate fur and drank blood, moved to avoid cold, and dwelled in shade to avoid heat. In that state of unadulterated simplicity, what diseases could there be? Later, Fu Xi observed the heavens and qi to draw the trigrams. The *Tianyuan Yuce* (*Jade Register of the Heavenly Origin*), later attributed to Fu Xi, was actually passed down orally through ten generations by Gui Yu Qu. Shennong tasted hundreds of herbs, suffering poison seventy times in a single day, after which Materia Medica arose. Huangdi (Yellow Emperor), wearing robes to govern the world, engaged in mutual questioning with Tianshi Qibo, pushing up to astronomy, exhausting down to geography, and deeply understanding the sufferings of the people. Thus, the *Neijing* (*Inner Canon*) was created. Once this classic was established, when people suffered from illness, they necessarily relied on Bian stones and needles to treat external conditions, and decoctions to treat internal conditions. Thereafter, as simplicity scattered and civilization opened, people's affairs became complex and desires unrestrained, leading to various disasters. Only medicines of varying toxicity—great, small, common, and non-toxic—could dispel these ailments. The great source of medicine lies solely in the *Suwen* (*Basic Questions*).
Comprising twenty-four volumes and eighty-one chapters, it deduces the principles of Luck (Yunqi) and their influences, clarifies the root and branch of the Meridians, discusses diseases focusing on essentials, and prescribes treatments appropriately. It is orderly and coherent. Chapters such as *Tianyuan Ji Dalun*, *Liuyuan Zhengji Dalun*, *Wuchang Zheng Da Lun*, *Qiaojiao Bian Dalun*, and *Zhizhen Yao Dalun* contain the most profound and subtle truths. Indeed, they are grand classics for freeing humanity from bondage and hardship for millennia, preserving true Qi, guiding vital energy, saving the common people into benevolence and longevity, and helping the frail find peace.
Since Xuanyuan (Huangdi) and Qibo, generations have not lacked talent. Bian Que grasped some of it, elaborating and writing the *Nanjing* (*Classic of Difficult Issues*). Huangfu Mi organized it into the *Jiayi Jing*. Yang Shangshan compiled it into the *Taisu*. Such as Quan Yuanqi’s commentary and Wang Bing’s (Zixuanzi) annotations exemplify the principle that if the source is pure, the stream is clear; if the trunk is straight, the shape is correct. These are the renowned physicians of past dynasties. However, Zhang Zhongjing, Grand Administrator of Changsha in the Han Dynasty, investigated roots and sources, explored hidden subtleties, selected prescriptions of various sizes and structures, established the methods of Sovereign, Minister, Assistant, and Courier (Jun-Chen-Zuo-Shi), and created medical formulas addressing exterior-interior and deficiency-excess. This was indeed a secret not transmitted for a thousand years, possessing the qualities of a Great Sage and Second Sage, with merit in continuing the past and opening the future.
After the Han and Tang dynasties, did scholars not wish to explore its profound mysteries? Moreover, since the principles of the *Neijing* are deep and obscure, with no direct path to entry, works like Chao Yuanfang’s *Bingyuan* (*Source of Diseases*) and Sun Simiao’s *Qianjin Fang* (*Prescriptions Worth a Thousand Gold*) became more verbose yet less clear, with more formulas but lost methods. Consequently, the application of the *Neijing* became rare. When Zhu Fengyi (Zhu Gong) followed Zhang Zhongjing’s theories and compiled the *Nanyang Huoren Shu*, he interpreted Yin-Yang as Cold-Heat, whereas Zhang Zhongjing interpreted them as Exterior-Interior. A difference of a hair led to an error of a thousand miles. Although he saved many, he also failed to save many. Fortunately, Liu Wansu’s *Yaozhi Lun* and *Yuanbing Shi* clarified the principles of the *Neijing* like the sun and moon. His *Zhige* and *Xuanming Lun* simplified Zhang Zhongjing’s methods to essential pivots. For instance, changing Guizhi Mahuang Ban Tang to Shuangjie San, or transforming Shizao Tang into Sanhua Shenyao Wan, his contribution to the sacred tradition was significant.
Contemporaneously, Zhang Zihe emerged, elucidating the great Dao of the *Neijing* and continuing the orthodox source of Hejian (Liu Wansu). He studied with Ma Zhiji to write *Rumen Shiqin*, stating: "Vomiting contains sweating; purging contains tonification. The Sages had only three methods, no fourth." This is an unchangeable truth and a supreme maxim, giving rise to the Liu-Zhang school.
As for Laodong Yuan (Li Gao), he understood the *Suwen*, respected Zhang Zhongjing’s methods, and transmitted ten books including *Pibei Congshu*. He used balance and rules for pulse diagnosis, and applied the ascending-descending and floating-sinking properties of herbs, leading to analogies of Kingly and Hegemonic ways. Danxi Zhu Zhenheng meticulously studied cold damage, internal injury, and miscellaneous diseases, with unique insights into phlegm-fire. Song Liao, Grand Historian of Song, said he gathered the great achievements of medical families—a true statement.
In our dynasty, the revision of *Daguan Bencao*, the compilation of *Tongren Xuewei Zhenjiu Jing*, and imperial bestowals of medical texts, along with the establishment of Imperial Physicians, Royal Physicians, and Public Welfare Pharmacies to aid the people, reflect a benevolence toward the world consistent with Xuanyuan and Qibo, far surpassing Han and Tang. Thus, famous doctors emerged continuously: Tao Jie’an’s work on cold damage revealed what Zhang Zhongjing had not; Xue Ji’s surgery supplemented Li Gao’s omissions; Ge Kejiu’s internal injuries and Qian Ying’s pediatrics did not disgrace Danxi. The merit of this enlightened era in cultivating talent is magnificent! If later learners understand the origin of the orthodoxy, their path will not err, and the Way of Medicine can be approached. Hence it is said: "He who knows the essentials needs but one word to conclude."