万物之生，负阴而抱阳，冲气以为和。故上古之人，其知道者，法于阴阳，和于术数。
阴阳者，术数之本；术数者，阴阳之着。而非知道不能，医可易言乎哉？医之道，譬若宫墙
。辨虚实，审寒热，其门径也。门径苟差，何由升堂入室乎？世人涉猎方书，讲求形证，自
以为能，是犹寝馈于门户之间，不复知有堂室矣！而或者高语《内》、《难》，虚言脉要，
则又如天际之翔，出于丰屋之上，奥 之间，毕生莫睹。二者虽异，其弊则均。盖人之
生也，有原，则其所以病，亦有原。明乎其原，而后针石之投，汤液醪醴之设，非臆度而悬
揣，
初识之于京邸，恂恂若无能者，嗣闻其善医，视其方亦似与人无殊特者，而应手辄效。叩
之以其故，则曰世人习用之方，大率类此，而轻重之准，刚柔之质，先后之宜，非识者难言
之矣！客冬以团练之役，访之于涟城，就询时务，虽一乡一邑之设施，而洞见 结，因地制
宜，亦如随证立方焉！洵医国之妙手，而非无本之谈也。因求其所着《医原》读之，本末贯
串，文本昭晰，可以一见了如，而欲穷就义蕴，辄有望洋之嗟！信乎？能达其原，而岐伯
之奥旨，仲景之秘思，中法西法之妙用，一以贯之矣。夫欲上太行必恃车马；欲导积石
必恃舟航。世之掇拾类书，强记药性，衣食于医者，或无取乎是书；若立志活人，而欲进于
古之知道者，则是书实医家之车马舟航矣。故亟怂恿付梓，而书数言于篇首，以告世之学
医者。
时咸丰十有一年辛酉夏月清河愚弟吴昆田谨序
万物之生长，背负阴气而怀抱阳气，通过冲和之气达到和谐状态。所以上古时代的人，那些通晓大道的人，效法阴阳规律，调和于养生术数之中。
阴阳是术数的根本；术数是阴阳的具体显现。如果不通晓大道，医学岂能轻易谈论呢？医学之道，好比宫室的围墙。辨别虚实、审察寒热，就是入门的门径。如果门径有误，怎么能登堂入室呢？世人只是浏览方书，讲究外形症状，自认为有能力，这就像在门户之间睡觉吃饭，不再知道有厅堂和内室了！有的人高谈《内经》、《难经》，空谈脉理要领，又好像在天际飞翔，超出丰屋之上，深奥之处，终身无法目睹。这两种情况虽然不同，但弊病是一样的。大概人的生存，有其本源，那么人之所以生病，也有其本源。明白了这个本源，然后施针用药，配制汤液醪醴，就不是主观臆测和凭空揣度了。
我在京城初次认识他时，他恭顺谦卑，好像没有什么能力的样子，后来听说他擅长医术，看他的药方也似乎与别人没有特别不同之处，然而一用就见效。询问其中的缘故，他说世人常用的方子，大体都类似这样，但是轻重的主次、刚柔的性质、先后的适宜，不是有见识的人难以说清的！去年冬天因为团练的事务，我到涟城拜访他，咨询时事，虽然是一乡一邑的施政措施，却能洞察症结所在，因地制宜，也像随证立方一样灵活！确实是治理国家的妙手，而不是没有根据的空谈。于是请求阅读他所著的《医原》，全书首尾贯通，文字清晰明白，可以一目了然，但如果想要穷尽其中的义理蕴藏，却常常发出望洋兴叹的感慨！确实如此啊，能够通达事物的本源，那么岐伯的深奥旨意、张仲景的隐秘思考，中医方法和西医方法的精妙运用，就能一贯相通了。想要登上太行山必须依靠车马；想要疏导积石山必须依靠舟船。世上那些拾取类书片段、强行记忆药性、靠行医谋生的人，或许不需要这本书；如果是立志救人，并且想要进身到古代通晓大道的人的境界，那么这本书实在是医家的车马和舟船啊。所以极力怂恿将其刻印出版，并在篇首写下这几句话，以告诉世上的学医者。
时在咸丰十一年辛酉夏季，清河愚弟吴昆田恭敬作序。
The generation of all things involves bearing Yin and embracing Yang, achieving harmony through the rushing Qi (vital energy). Therefore, people in ancient times who understood the Great Way modeled themselves on Yin and Yang and harmonized with their techniques and numbers (prescriptive methods for health preservation).
Yin and Yang are the root of techniques and numbers; techniques and numbers are the manifestation of Yin and Yang. Without understanding the Great Way, how can medicine be lightly discussed? The way of medicine is like the walls of a palace. Distinguishing deficiency and excess, examining cold and heat, are the gateways to entry. If the gateway is mistaken, how can one enter the hall and the inner chambers? People who merely browse prescription books and focus on external symptoms consider themselves capable; this is like sleeping and dining only within the gatehouse, unaware of the existence of the hall and inner chambers. Others speak loftily of the *Neijing* (Classic of Internal Medicine) and *Nanjing* (Classic of Difficult Issues), discussing pulse essentials in vain; this is like soaring in the sky above lofty roofs, never glimpsing the profound depths throughout their lives. Although these two approaches differ, their drawbacks are the same. Generally, human life has its origin; thus, the cause of disease also has its origin. Once the origin is clarified, the application of acupuncture and moxibustion, and the formulation of decoctions and fermented wines, are no longer based on subjective speculation or guesswork.
When I first met him in the capital, he appeared humble and modest, seemingly lacking ability. Later, hearing that he was skilled in medicine, I observed that his prescriptions seemed no different from others', yet they were effective immediately upon use. When asked about the reason, he said that the formulas commonly used by people are generally similar, but the standards of weight and lightness, the qualities of rigidity and flexibility, and the appropriateness of sequence are difficult to articulate without true insight. Last winter, due to militia duties, I visited him in Liancheng to inquire about current affairs. His administrative measures for a village or county revealed a clear understanding of the core issues, adapting to local conditions just as one prescribes formulas according to syndromes. He is truly a master of governing the body politic, not engaging in baseless talk. I then requested to read his work *Yi Yuan* (The Origin of Medicine). The book connects beginning and end seamlessly, with clear and lucid text, allowing for immediate comprehension. However, attempting to exhaust its profound meanings often leads to sighs of inadequacy before the vastness. Indeed, once one comprehends the origin, the profound teachings of Qibo, the secret thoughts of Zhang Zhongjing, and the subtle applications of both Chinese and Western medical methods can be integrated into one coherent system. To ascend Mount Tai, one must rely on carriages and horses; to channel the waters at Jishi Mountain, one must rely on boats and ships. Those who pick up fragments from encyclopedic works and forcibly memorize herb properties, making a living as physicians, may find little use for this book. But for those determined to save lives and aspire to reach the level of the ancients who understood the Great Way, this book is indeed the carriage, horse, boat, and ship for physicians. Therefore, I strongly urged its publication and wrote these few words at the beginning to inform students of medicine in the world.
Preface respectfully written by Wu Kuntian, humble younger brother from Qinghe, in the summer of the Xin You year, the 11th year of Xianfeng.