予出中年，尝游东藩之野，遇异人焉。偶相问曰∶子亦学医道耶？医道，难矣。子其慎
之。予曰∶医虽小道，而性命是关，敢不知慎，敬当闻命。异人怒而叱曰∶子非知医者也。
既称性命是关。医岂小道云哉？夫性命之道，本乎太极，散于万殊。有性命然后三教立，有
性命然后五伦生。故造化者，性命之炉冶也。道学人，性命之绳墨也。医药者，性命之赞育
也。然而其义深，其旨博，故不有出人之智，不足以造达微妙。不有执中之明，不足以辨正
毫厘。使能明医理之纲目，则治平之道如斯而已。能明医理之得失，则兴亡之机如斯而已。
能明医理之缓急，则战守之法如斯而已。能明医理之趋舍，则出处之义如斯而已。洞理气于
胸中，则变化可以指计，运阴阳于掌上，则隔垣可以目窥。修身心于至诚，实儒家之自治；
洗业障于持戒，诚释道之自医。身心人己，理通于一，明于此者，必明于彼。善乎彼者，必
善于斯。故曰∶必有真人，而后有真知，必有真知，而后有真医。医之为道，岂易言哉。若
夫寻方逐迹，龊龊庸庸，椒、硫杀疥，葱、薤散风，谁曰非医也？而缁衣黄冠，总称释道；
矫言伪行，何非儒流？是泰山之与丘垤，河海之与行潦，固不可以同日语矣。又若阴阳不识
，虚实误攻，心粗胆大，执拗偏庸，非徒无益而反害之之徒。殆又椒、硫、葱、薤之不若。
小道之称，且不可当。又乌足与言医道哉！医道，难矣。医道，大矣。是诚神圣之首传，民
命之先务矣。吾子其毋以草木相渺，必期进于精神相贯之区，玄冥相通之际，照终始之后先
，会结果之根蒂，斯于斯道也。其庶乎为有得矣。子其勉之！予闻是教，惭悚应诺，退而皇
皇者数月，恐失其训，因笔记焉。
我正值中年时，曾经游历到东藩的野外，遇到了一位奇异的人。他偶然问我道：“你也学习医道吗？医道，是艰难的啊。你要谨慎对待它。”我说：“医学虽然被视为小道，但关系到人的性命，怎敢不谨慎，恭敬地听从您的教诲。”那人发怒并呵斥道：“你并不是真正懂医的人。既然你说性命是关键，医学怎么可以说是小道呢？夫性命之道，本源在于太极，分散于万事万物之中。有了性命之后，儒、释、道三教才建立起来；有了性命之后，五伦（君臣、父子、夫妇、兄弟、朋友）才产生。所以，天地造化，是炼铸性命的熔炉；道学做人，是衡量性命的准绳；医药，是辅助养育性命的工具。然而其中的义理深邃，宗旨广博，所以如果没有超常的智慧，不足以达到精微奥妙的境界；没有执守中道的明智，不足以辨别毫厘之间的差异。如果能阐明医理的纲领和条目，那么治国平天下的道理也就如此罢了。如果能明辨医理的得失，那么国家兴亡的关键也就如此罢了。如果能明了医理的缓急，那么战争防守的策略也就如此罢了。如果能明了医理的取舍，那么出仕或隐居的道义也就如此罢了。在胸中洞察理气，那么变化就可以屈指计算；在掌上运转阴阳，那么隔着墙垣也可以目视窥探。通过至诚来修养身心，确实是儒家的自我治理；通过持戒来洗涤业障，确实是佛道二教的自我医治。身心与人己，道理相通为一，在此处明白的，必然在彼处也明白。在彼处擅长的，必然在此处也擅长。所以说：必须有真人，而后才有真知；必须有真知，而后才有真医。医道，哪里是容易言说的呢？至于那些寻找方剂、追随痕迹、拘谨平庸之辈，用花椒、硫磺杀灭疥疮，用葱、薤散发风邪，谁说他们不是医生呢？但是僧侣道士，总称为佛道；矫揉造作虚伪行为的人，何尝不是儒家流派？这就好比泰山与土堆，黄河大海与路边积水，本来就不可以相提并论了。又像那些不识阴阳、虚实误攻、心粗胆大、固执偏颇平庸之徒，不仅无益反而有害的人。这些人恐怕又不如花椒、硫磺、葱、薤了。‘小道’这个称呼，尚且承受不起，哪里值得与他们谈论医道呢！医道，艰难啊。医道，宏大啊。这确实是神圣传承的首要经典，是百姓性命的首要事务。希望你不要轻视草木药材，必须期望进入精神贯通的境界，玄妙冥通的际遇，照看始终的前后顺序，领会结果的根蒂，这样对于这道，大概就可以有所得了吧。你要努力啊！我听到这些教诲，惭愧惊恐地应答承诺，回去后惶恐不安了好几个月，担心失去他的训诫，因此记录下来。
When I was in middle age, I once traveled to the wilds of Dongfan and encountered an extraordinary person. He casually asked me, "Do you also study the Way of Medicine? The Way of Medicine is difficult. You must be cautious." I replied, "Although medicine is considered a minor art, it concerns human life and death; how could I dare not be cautious? I respectfully accept your instruction." The man became angry and rebuked me, saying, "You do not truly understand medicine. Since you acknowledge that life and death are paramount, how can medicine be called a minor art? The Way of Life and Death originates from the Supreme Ultimate (Taiji) and manifests in myriad distinctions. With life and death established, the Three Teachings (Confucianism, Buddhism, and Daoism) were founded; with life and death established, the Five Relationships (ruler-minister, father-son, husband-wife, elder-younger brother, friend-friend) arose. Thus, Creation is the furnace and forge for refining life and death; the study of the Dao is the plumb line for measuring life and death; medicine and pharmacy are the assistants in nurturing life and death. However, its principles are profound and its purport extensive. Therefore, without exceptional wisdom, one cannot attain subtlety and profundity; without clarity in holding the Mean, one cannot distinguish minute differences. If one can clarify the outline and details of medical theory, then the way to govern and pacify the world is but this. If one can discern the gains and losses of medical theory, then the mechanism of rise and fall of states is but this. If one can understand the urgency and delay in medical theory, then the methods of warfare and defense are but this. If one can understand the preference and rejection in medical theory, then the righteousness of entering or retiring from public service is but this. By penetrating Li Qi (Principle and Vital Energy) within the chest, changes can be counted on fingers; by manipulating Yin and Yang upon the palm, one can see through walls. Cultivating body and mind through utmost sincerity is indeed the self-governance of Confucianism; washing away karmic obstacles through observance of precepts is indeed the self-healing of Buddhist and Daoist traditions. Body, mind, self, and others share a unified principle; one who understands here will necessarily understand there. One who excels there will necessarily excel here. Thus it is said: Only when there are True Persons (Zhenren) can there be True Knowledge; only when there is True Knowledge can there be True Physicians. How easy is it to speak of the Way of Medicine! As for those who merely seek formulas and follow traces, being petty and mediocre—using Zanthoxyli Pericarpium (Jiaojiao, 花椒) and Sulfur (Liuhuang, 硫磺) to kill scabies, using Allii Fistulosi (Congbai, 葱) and Allii Macrostemonis Bulbus (Xie, 薤) to disperse wind—who would say they are not physicians? Yet monks and Daoist priests are collectively called Buddhist and Daoist; those with pretentious words and false conduct are no less Confucian scholars. This is like comparing Mount Tai with a small mound, or the Yellow River and Sea with puddles in a rut; they certainly cannot be discussed on the same day. Furthermore, those who fail to recognize Yin and Yang, mistakenly attack deficiency patterns as excess, are careless and bold, stubborn and biased/mediocre—they are not only useless but harmful. Such people are likely inferior even to Jiaojiao, Liuhuang, Congbai, and Xie. They cannot even bear the title of 'minor art,' let alone discuss the Way of Medicine! The Way of Medicine is difficult. The Way of Medicine is great. It is truly the primary transmission of the sages and the foremost concern for the lives of the people. Do not despise herbs and plants; you must strive to enter the realm where spirits interpenetrate and the boundary where the mysterious communicates, illuminating the sequence of beginning and end, and grasping the root of results. In this way, you may perhaps gain something in this Way. Strive hard! Upon hearing these teachings, I felt ashamed and terrified, responding with assent. For months afterward, I remained anxious and unsettled, fearing I might lose his instructions, so I recorded them in writing.