经曰∶揆度奇恒，道在于一，得一之精，以知死生，此即斯道中精一执中之训也。凡天
人之学，总无出此。矧医之为道，性命判于呼吸，祸福决自指端，此于人生关系，较之他事
为尤切也。以此重任，使不有此见此识，诚不可猜摸尝试以误生灵。矧立法垂训，尤难苟且
，倘一言失当，则遗祸无穷，一剂妄投，则害人不浅。此误谬之不容不正也。
宾自从斯道，常稽往古，所见轩岐之下，凡明良继出，何代无之。然必欲求其得中者，
则舍《灵》《素》之外，似亦不多其人。盖窃见相传方论，每多失经意，背经旨，断章取义
。假借数语以饰一偏之诡说者，比比其然。此总属意见有不到，至理有未明，故各逞胸臆，
用示已长。致令斯道失中，大违精一之义。此则医之于人，亦何赖焉。是岂知道本一源，理
无二致。自一源而万变，则万变仍归于一，自二致而错乱，则错乱遂其为两。故言外有理，
理外亦有言。如理有在而言不能达者，此言外之理也；有可以言而不可以行者，此理外之言
也。然理外岂别有言乎？第以疑似之间，加之便佞，则真为伪夺，而道傍之筑，从来有矣。
如古之杨墨异端，今之传奇小说，谓皆非理外之言乎？言可假借，则是非乱而强辩出。由是
贤者固执，愚者亦固执。如择善固执，则精一之谓，君子时中，则执中之谓，此贤者之固执
也；其有言伪而辩，行僻而坚，必不知反，必不可移者。此愚者之固执也。执中者，见事之
舛，则不得不言，以利害所关，不容已也；邪僻者，见人之长，则反诋其短，以鄙陋不伸，
不肯已也。千古来是非邪正，每为此害，矧以惟类知类，而当局者亦难其人耳。然此辈虽云
偏拗，犹知傍理，自非曳白者所能。其奈此中尚有全不知脉络，而止识皮毛者，亦且嚣嚣，
偏能宜俗，是不过见热则用寒，见寒则用热，见外感则云发散，见胀满则云消导。若然者，
谁不得而知之。设医止于是，则贱子庸夫皆堪师范，又何明哲之足贵乎？嗟！嗟！朱紫难辨，
类多如此。
予因溯源稽古，即自金元以来为当世之所宗范者，无如河间、丹溪矣。而且各执偏见，
左说盛行，遂致医道失中者，迄今四百余年矣。每一经目，殊深扼腕，使不速为救正，其流
弊将无穷也。兹姑撮其数条，以见倍理之谈，其有不可信者类如此，庶乎使人警悟，易辙无
难，倘得少补于将来，则避讳之罪，亦甘为后人而受之矣。
《黄帝内经》说：衡量事物的常与变，关键在于把握统一的原则；掌握了这一精髓，就能知晓生死存亡的道理。这正是医学之道中“精一执中”的教诲。凡是关于天道与人道的学问，都不出这个范围。况且医学作为一门学科，人的性命在呼吸之间即可判明，祸福取决于医生的指尖（诊疗），这与人生的关系，比其他事情更为密切。承担如此重任，如果没有这种见解和认识，确实不能靠猜测和尝试来误害生灵。况且制定法则、流传训诫，尤其不能草率苟且，如果一句话失当，就会留下无穷的祸患；如果一味乱投药方，就会对人不浅的伤害。这就是误谬之处不容不纠正的原因。
我自从研习此道以来，常常考察古代文献，所见到的从轩辕、岐伯以下，凡是有贤明的君主和良医相继出现，哪个朝代没有呢？然而一定要寻求其中能够把握中庸之道的，那么除了《灵枢》和《素问》之外，似乎也没有多少人了。我私下看到相传的方论，大多偏离了经典的本意，违背了经典的宗旨，断章取义，借几句言辞来掩饰片面的诡辩，这种情况比比皆是。这总归是见解有所不到，至理未能明了，所以各自逞显胸臆，用来显示自己的长处。致使这门学问失去中正，大大违背了精一的意义。这对于医学对于人的作用，又有什么依赖呢？这难道不知道道理本出于一个源头，真理没有两种趋向吗？从一个源头衍生出万变，那么万变仍然回归于一；从两种趋向导致错乱，那么错乱就成为了两样。所以言语之外有道理，道理之外也有言语。比如道理存在但言语无法表达的，这是言语之外的道理；有可以说出来但不可以实行的，这是道理之外的言语。然而道理之外难道另有言语吗？只是在似是而非之间，加上巧言令色，那么真就被伪所夺，路边筑墙（指无根据的议论）的事情，从来就有啊。就像古代的杨朱、墨翟异端，现在的传奇小说，能说它们不是道理之外的言语吗？言语可以被假借，那么是非就会混乱，强辩就会兴起。由此贤者固执己见，愚者也固执己见。如选择善道而固执坚守，这就叫精一；君子随时保持适中，这就叫执中，这是贤者的固执；那些言语虚伪却善辩，行为偏激却坚定，必定不知反省，不可改变的人，这是愚者的固执。执中的人，看到事情的谬误，就不得不说，因为利害相关，不得不发；邪僻的人，看到别人的长处，反而诋毁其短处，因为鄙陋之心不得伸展，不肯停止。千古以来的是非邪正，常常为此所害，何况同类相知，而身处其中的人也难得其人啊。然而这类人虽然说是偏执拗口，还知道依傍道理，自不是那些交白卷（指一无所知）的人所能比的。无奈这其中还有完全不知道经络脉络，只识得皮毛的人，也喧哗自得，偏偏能迎合世俗，不过是见到热证就用寒药，见到寒证就用热药，见到外感就说发散，见到胀满就说消导。像这样的人，谁不知道呢？假如医生只是做到这样，那么卑贱平庸的人都可以成为师范，又何必推崇明智哲人呢？唉！唉！朱紫难辨，大抵都是如此。
我因此追溯源头考察古事，即自金元以来被当世所宗法典范的，没有比刘河间、朱丹溪更著名的了。而且他们各执偏见，左派学说盛行，致使医道失去中正，到现在四百多年了。每次读到这些，都深感扼腕叹息，如果不迅速加以救正，其流弊将无穷无尽。这里姑且摘录其中的几条，以展示违背常理的言论，那些不可信的类同于此，希望使人警醒觉悟，改变方向并不难，倘若能对将来稍有补益，那么避讳的罪过，我也甘愿为后人而承受。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: "To measure the unusual and the ordinary, the Dao lies in unity; grasping the essence of this unity allows one to know life and death." This is precisely the teaching of "refined unity and holding the mean" within the medical Dao. All studies concerning Heaven and humanity do not transcend this principle. Moreover, medicine as a discipline determines life and death in the span of a breath, and decides fortune or misfortune by the tip of the fingers (diagnosis and treatment). Its relationship to human life is more critical than any other matter. To bear such heavy responsibility, without such insight and understanding, it is indeed impossible to rely on guessing and experimentation, which would only harm living beings. Furthermore, establishing laws and transmitting teachings requires utmost seriousness; one cannot be casual. If a single statement is inappropriate, it may cause endless disaster; if a prescription is blindly administered, it will severely harm people. This is why errors and fallacies must not go uncorrected.
Since I began studying this path, I have often examined ancient texts. From Xuanyuan (Yellow Emperor) and Qibo downwards, whenever wise rulers and virtuous physicians emerged successively, which dynasty lacked them? However, if one seeks those who truly grasp the "mean," apart from the *Ling Shu* (Spiritual Pivot) and *Su Wen* (Basic Questions), there seem to be very few. I privately observe that transmitted formulas and theories often deviate from the original meaning of the classics, contradict their principles, and take passages out of context. Borrowing a few phrases to embellish one-sided, erroneous theories is common everywhere. This generally stems from incomplete insights and an unclear understanding of profound truths, leading individuals to display their own opinions to show off their strengths. Consequently, this discipline loses its balance, greatly violating the meaning of refined unity. What reliance can medicine offer to humanity under such circumstances? Does one not realize that the Dao originates from a single source, and truth has no dual directions? From one source arise ten thousand changes, yet these changes still return to unity; from dual directions arise confusion, leading to division into two. Thus, there is reason beyond words, and words beyond reason. For instance, when reason exists but words cannot express it, this is reason beyond words; when something can be spoken but not practiced, this is words beyond reason. But is there really separate speech beyond reason? Only when ambiguity is exploited with flattery does falsehood usurp truth, just as baseless arguments ("building walls by the roadside") have always existed. Consider the heterodox schools of Yang Zhu and Mo Di in ancient times, or legendary novels today; can they be said not to be words beyond reason? When words are borrowed falsely, right and wrong become confused, and strong辩论 (strong argumentation) arises. As a result, the wise become stubborn, and the foolish also become stubborn. Choosing goodness and adhering firmly to it is called "refined unity"; the gentleman maintaining appropriateness at all times is called "holding the mean"—this is the stubbornness of the wise. Conversely, those whose words are false yet eloquent, whose actions are perverse yet firm, who refuse to reflect and cannot be moved, exhibit the stubbornness of the foolish. Those who hold the mean speak up when they see errors because of the stakes involved; those who are perverse criticize others' strengths due to their own petty frustrations. Throughout history, right and wrong, orthodoxy and heresy, have often suffered from this. Moreover, among peers, it is difficult to find qualified individuals. Although these biased individuals still claim to follow reason, unlike those who submit blank papers (know nothing), there are still those within the field who completely ignore meridians and collaterals, knowing only superficial aspects, yet they boast loudly and cater to popular tastes. They merely apply cold remedies for heat signs, hot remedies for cold signs, dispersing methods for exterior syndromes, and resolving stagnation for fullness. Who does not know this? If doctors stop here, even humble and mediocre persons could serve as models, rendering the wisdom of the enlightened worthless. Alas! Alas! It is hard to distinguish cinnabar from purple (right from wrong); most are like this.
Therefore, tracing back to the sources and examining antiquity, since the Jin and Yuan dynasties, the figures revered as paradigms by the contemporary world were none other than Liu Wansu (Hejian) and Zhu Zhenheng (Danxi). Yet each held biased views, causing left-leaning theories to prevail, resulting in the medical Dao losing its balance for over four hundred years to date. Every time I read these works, I feel deeply frustrated. If we do not swiftly correct these errors, their detrimental effects will be endless. Here, I briefly excerpt a few points to demonstrate how absurd these claims are, showing that the unbelievable is similar to this, hoping to awaken people so that changing course is not difficult. If this can provide slight benefit to the future, I am willing to bear the blame of taboo-breaking for the sake of later generations.