医之为道。难言矣。必审诊以起度量。立规矩。称权衡。合色脉。表里。有余。不足。顺逆。之法。复参其人之动
静。与其息之相应。然后从而治之。非洞明应世群书之得失。不足与于斯。黄帝内经。虽疑先秦之士。根据仿而托之。其
言深。其旨邃。以弘其考辨。信而有征。是当为医家之宗。下此则秦越人和缓。无书可传。越人所着八十一难经。则皆
举内经之要。而推言者也。又下此。则淳于意华佗之熊经鸱顾。固亦导引家之一术。至于刳腹背。湔肠胃。而去疾。则
涉于神怪矣。意之医状。司马迁备志之。其所谓回风杳风者。今人绝不知为何证。况复求于治疗之深旨乎。又下。则张
机。机之金匮玉函经。及伤寒诸论。诚千古不刊之典。第详于六气所伤。而于情欲食饮。罢劳之所致者。略而弗议。兼
之文本错简。亦未易以序次求之也。又下此。则王叔和。叔和纂歧伯华佗等书。为脉经。叙阴阳内外。辨三部九候。分
人宁气和。条陈十二经络。洎夫三焦五脏六腑之病。最为着明。惜乎为妄男子。括以肤陋之脉歌。遂使其本书。不盛布
于世也。又下此。则巢元方。其病源候论。似不为无见。但言风寒二湿。而不着湿热之文。乃其失也。又下此则王 。
推五运六气之变。撰为天元王策。周详切密。亦人所难。苟泥之。则属滞而不通矣。又下此。则王焘孙思邈。思邈以
绝人之识。操慈仁恻浓之心。其列千金方翼。及工害人之祸。至为愤切。后人稍闯其藩垣。亦足以其术鸣。但不知伤寒
之数。或弗能无遗憾也。熏虽暗劣。外台秘要。所言方证符禁灼灸之详。颇有所祖述。然谓针能杀生人。而不能起死人
者。则一偏之见也。又下此。则钱乙庞安时许叔微。叔微在准绳尺寸之中。而无所发明。安时虽能出奇应变。而终未离
于范围。二人皆得张机之粗者也。惟乙深造机之阃奥。而撷其精华。建为五脏之方。各随所宜。肝有相火。则有泻而无
补。肾为真水。则有补而无泻。皆启内经之秘。世概以婴孺医目之。何知乙之浅哉。其遗书散之出于阎孝忠所集者。多
孝忠之意。初非乙之本真也。又下此。则工谷张元素。河间刘完素。睢水张从正。元素之与完素。虽设为奇梦异人。以
神其授受。实闻乙之风而起者。若从正则又宗完素者也。元素以古方新病。决不能相值。治疾一切不以方。故其书亦不
传。其存于今者。皆后来之所傅会。其学则东垣李杲深得之。杲推明内外二伤。而多注意于补脾土之说。盖以土为一身
之主。土平则诸脏平矣。从正以吐汗下三法。风寒暑湿火燥六门。为医之关键。其治多攻。其剂多峻厉。不善学人杀人。
光素论风火之病。以内经病机气宜十九条。着为元病式。简奥粹微。有非大观局诸医。所可仿佛。究其设施。则亦不越
补攻二者之间也。嗟乎。自有内经以来。医书之藏有司者。凡一百七十九家。二百九部。二千二百五十九卷。他未遑深
论。即今所论者言之。世之医师。果能尽心于斯否乎。脱或未尽心于斯。则夫起度量。立规矩。称权衡。合色脉之属。
焉能察而行之。不至以人命为戏也。几希矣。虽然亦有要焉。逆与顺之谓也。曰升降。曰浮沉。吾则顺之。曰温凉。曰
寒热。吾则逆之。果能此道矣。则去夫先医之所治。虽不中。不远矣。乌伤。贾思诚。濂外弟也。尝同濂。师事城南闻
先生。学治经。久之复受医说于彦修宋先生。治疾有奇验。荐绅间多为赋诗。而属濂以序。濂为直疏历世群书之得失。
而最思诚以学人如此。
医学这一道，真是难以言说啊。必须通过审慎的诊断来确立度量标准，建立规矩法度，称量权衡轻重，综合观察面色与脉象，分析表里、有余不足、顺逆等法则，再参考病人的动静状态以及呼吸气息的相应变化，然后才能进行治疗。如果不是对历代群书的得失洞明透彻，不足以参与此道。《黄帝内经》虽然有人怀疑是战国时期的人仿效并托名之作，但其言辞深奥，旨意深远，经过考证辨析，确凿有据，应当作为医家的宗师。在此之下，则是秦越人（扁鹊）和缓，没有著作流传下来。秦越人所著的《八十一难经》，都是列举《内经》的要旨而推演阐述的。再往下，则是淳于意和华佗，他们练习“熊经鸱顾”（一种导引术），固然是导引家的一种技艺，至于剖开腹部、清洗肠胃以去除疾病，则涉及到神怪之事了。淳于意的医疗事迹，司马迁在《史记》中记载得很详细，其中所说的“回风”、“杳风”等病证，今人完全不知道是什么病症，更何况去探求治疗上的深意呢？再往下，则是张机（张仲景）。张机的《金匮玉函经》及《伤寒论》诸篇，确实是千古不可磨灭的经典。只是详细论述了六气所致的伤害，而对于情志欲望、饮食劳倦所致的问题，却简略而未加议论。加之文本存在错简（竹简顺序错乱），也不容易按次序整理明白。再往下，则是王叔和。王叔和编纂岐伯、华佗等人的书籍，写成《脉经》，叙述阴阳内外，辨别三部九候，分辨人的宁静与气机调和，条理清晰地陈述十二经络，以及三焦五脏六腑的疾病，最为显著明确。可惜他是个品行不端之人，用肤浅粗陋的脉歌概括，致使他的原著未能广泛流传于世。再往下，则是巢元方。他的《诸病源候论》，似乎并非没有见解，但只谈论风寒湿，而没有涉及湿热的内容，这是他的缺失。再往下则是王冰，他推演五运六气的变化，撰写为《天元玉册》，周详严密，也是常人难以做到的。如果拘泥于此，就会显得滞涩不通。再往下，则是王焘和孙思邈。孙思邈凭借超凡的见识，秉持慈悲仁爱之心，他在《千金方》及《翼方》中，以及关于医生害人的祸患论述，极为愤慨急切。后人稍微窥探其门径，也足以凭借医术闻名。只是不知他对伤寒病的论述，或许不能没有遗憾吧。我黄琳虽然愚钝劣拙，但对《外台秘要》中所说的方证符禁、灼灸的详细情况，颇有继承阐述。然而他说针灸能杀死活人，却不能救活死人，这是一种偏颇的看法。再往下，则是钱乙、庞安时、许叔微。许叔微在规范尺寸之中，没有什么发明创造；庞安时虽然能出奇制胜、随机应变，但最终未脱离常规范围。这两人都只是得到张机医术皮毛的人。只有钱乙深入探究张机的奥秘，汲取其精华，建立五脏的方剂，各自随宜而定。肝有相火，所以只泻不补；肾为真水，所以只补不泻，这些都开启了《内经》的秘密。世人大概把他看作儿科医生，哪里知道钱乙并不浅薄呢？他的遗书散见于阎孝忠所集录的书中，大多包含阎孝忠的意思，起初并非钱乙的本真面貌。再往下，则有张元素、刘完素、张从正。张元素与刘完素，虽然设置奇梦异人来神化他们的传授过程，实际上是受钱乙风气影响而起。至于张从正，又宗奉刘完素的学说。张元素认为古方与新病绝对不能对应，治疗疾病一概不用固定方剂，所以他的书也没有流传下来。现在存世的，都是后来附会之作。他的学问，东垣李杲深得其中精髓。李杲推明内伤和外伤，而多注意于补脾土的说法。大概因为土是身体的主宰，土平则各脏都平了。张从正以吐、汗、下三法，风寒暑湿火燥六门，作为医学的关键。他的治疗多以攻邪为主，药方多峻猛严厉，不善于学习的人会因此杀人。刘完素论述风火之病，依据《内经》病机气宜十九条，著成《原病式》，简洁深奥精微，不是那些大观局出版的医书所能比拟的。究其施治手段，也不过在补法和攻法之间罢了。唉！自从《内经》以来，收藏在官府中的医书，共有一百七十九家，二百九部，二千二百五十九卷。其他的不必深论，就今天所论述的这些来说，世上的医师，果真能尽心于此吗？倘若不能尽心于此，那么那些确立度量、建立规矩、称量权衡、综合色脉之类的方法，怎么能察知并施行呢？不至于把人的生命当儿戏吗？希望渺茫了啊。虽然如此，也有要点所在，就是逆与顺的关系。对于升降、浮沉，我们顺应它；对于温凉、寒热，我们逆转它。果真能掌握这个道理，那么即使不去参考先医的治疗，虽然不一定正中靶心，也不会相差太远。乌伤的贾思诚，是我的表弟。曾经和我一同拜师城南闻先生学习，后来又向彦修宋先生请教医理。他治病有奇特的疗效，士大夫们多为他赋诗，并嘱托我为他作序。我便直率地梳理了历代群书的得失，并特别推崇贾思诚这样学识渊博的医者。
The Way of Medicine is indeed difficult to describe. One must conduct a careful diagnosis to establish standards of measurement, set rules and norms, weigh the balance of excess and deficiency, integrate the observation of complexion and pulse, analyze the methods of exterior and interior, surplus and deficit, and compliance and opposition. Furthermore, one must consider the patient's dynamic and static states as well as the correspondence of their respiration, before proceeding with treatment. Without a profound understanding of the merits and demerits of various classical texts, one cannot partake in this art. Although there are doubts that the *Huangdi Neijing* (Yellow Emperor's Inner Canon) was fabricated by scholars of the Warring States period under a false name, its language is profound and its purport is subtle. After rigorous textual criticism, it is verified and reliable, and thus should be regarded as the ancestor of medical schools. Below this level come Bian Que (Qin Yueren) and Huan Zi, who left no written works. The *Nanjing* (Classic of Difficult Issues), authored by Bian Que, enumerates the essentials of the *Neijing* and expands upon them. Further down are Chunyu Yi and Hua Tuo; their practice of "Bear Hanging and Owl Gazing" (Xiong Jing Chi Gu, a form of Daoist breathing and movement exercise) belongs to the category of Daoyin techniques. As for procedures involving opening the abdomen and washing the intestines to remove disease, these border on the miraculous or bizarre. Sima Qian recorded Chunyu Yi's medical cases in detail in the *Shiji* (Records of the Grand Historian). However, conditions such as "Huifeng" and "Yaofeng" mentioned therein are completely unknown to modern people, let alone understanding their deep therapeutic principles. Next comes Zhang Zhongjing (Zhang Ji). His *Jinkui Yufan Jing* (Golden Cabinet Jade Box Classic) and his treatises on Cold Damage (*Shanghan Lun*) are truly immortal classics of the ages. However, they detail injuries caused by the Six Qi (Wind, Cold, Summer-heat, Dampness, Dryness, Fire) but briefly neglect issues arising from emotions, desires, diet, and overexertion. Moreover, due to textual disarray (cuojian) in the bamboo slips, it is not easy to arrange them in order. Following him is Wang Shuhe, who compiled books by Qibo, Hua Tuo, and others into the *Maijing* (Pulse Classic). He described Yin and Yang, internal and external aspects, distinguished the Three Regions and Nine Pulses, differentiated between tranquility and qi harmony, and systematically listed the Twelve Meridians and diseases of the Triple Burner, Zang organs, and Fu organs, which was remarkably clear. Regrettably, he was a man of poor character who summarized his work with superficial pulse rhymes, causing his original book to fail to spread widely. Next is Chao Yuanfang. His *Zhubing Yuanhou Lun* (Treatise on the Pathogenesis and Manifestations of All Diseases) shows insight, but his omission of Damp-Heat alongside Wind-Cold-Dampness is a flaw. Below him is Wang Bing, who deduced the changes of the Five Movements and Six Qi, writing the *Tianyuan Yu Ce*. His work was detailed and precise, though rigid adherence to it leads to stagnation. Next are Wang Tao and Sun Simiao. Sun Simiao possessed extraordinary wisdom and a compassionate heart. In his *Qianjin Yaofang* (Essential Prescriptions Worth a Thousand Gold) and *Qianjin Yifang*, as well as his warnings about the dangers of incompetent physicians, he expressed deep indignation. Later generations who glimpsed his teachings could achieve fame through medicine, though perhaps lacking depth in Cold Damage theory. I, Huang Lin, though dull and inferior, have elaborated on the prescriptions, talismans, prohibitions, moxibustion, and cauterization details found in Wang Tao's *Waitai Miyao*. However, his claim that acupuncture can kill the living but cannot revive the dead is a biased view. Further down are Qian Yi, Pang Anshi, and Xu Shuwei. Xu Shuwei made little innovation within established norms; Pang Anshi could adapt flexibly but remained within conventional bounds. Both only grasped the superficial aspects of Zhang Zhongjing's art. Only Qian Yi delved into the profound secrets of Zhang Zhongjing, extracting the essence to formulate treatments for the Five Zang organs according to their specific needs. Since the Liver contains Ministerial Fire, it requires draining rather than tonifying; since the Kidney is True Water, it requires tonifying rather than draining. These insights unlocked the mysteries of the *Neijing*. The world generally dismisses Qian Yi as merely a pediatrician, failing to recognize his depth. His surviving writings, collected by Yan Xiaozhong, often reflect Yan's own ideas rather than Qian's true intent. Below them are Zhang Yuansu, Liu Wansu, and Zhang Congzheng. Zhang Yuansu and Liu Wansu used mystical dreams to legitimize their transmissions, yet were inspired by Qian Yi. Zhang Congzheng followed Liu Wansu. Zhang Yuansu argued that ancient formulas do not fit new diseases, treating all illnesses without fixed prescriptions, so his works did not survive; extant texts are later fabrications. His learning was best inherited by Li Dongyuan (Li Gao), who clarified internal and external injuries, emphasizing the tonification of Spleen Earth, as Earth is the master of the body; when Earth is balanced, all organs are balanced. Zhang Congzheng emphasized the three methods of vomiting, sweating, and purging, and the six pathogenic factors (Wind, Cold, Summer-heat, Dampness, Fire, Dryness) as key to medicine. His treatments were largely aggressive and his prescriptions harsh; improper use could be fatal. Liu Wansu discussed Wind-Fire diseases based on the Nineteen Pathomechanisms of the *Neijing*, writing the *Yuanbing Shi*. It was concise and profound, unmatched by contemporary medical publications. Ultimately, his methods still fell within the spectrum of tonification and draining. Alas! Since the *Neijing*, there have been 179 authors, 209 volumes, and 2,259 scrolls of medical texts stored in official libraries. Ignoring others, regarding those discussed here: do physicians today truly devote themselves to this? If not, how can they apply standards of measurement, rules, weights, and integrated pulse-complexion analysis without treating human life as a game? Hope is slim. Nevertheless, there is a key principle: compliance and opposition. For ascending/descending and floating/sinking, we comply; for warming/cooling and cold/heat, we oppose. Mastering this way, even without referencing past physicians' treatments, one will not miss the mark significantly. Jia Sicheng from Wushang is my cousin. He studied classics with me under Master Wen of the South City, and later learned medicine from Master Song Yanxiu. He achieved remarkable cures, inspiring poems from literati who asked me to write a preface. I have straightforwardly analyzed the merits and demerits of historical texts and highly praise Jia Sicheng for his scholarly approach.