伤寒一症，虽有活人书、明理论、指掌图、伤寒论全生集等书，其间有论缺方，有分失论，有脉无症，有
有症无法者，何哉。盖缘历年既久，遗失颇多，实非仲景之全书也。后之王叔和、以断简残编而补方造
论，成无己、以顺文注释而集成全书，所以遗祸至今而未止也。嗟乎，仲景之书失全，伤寒之病枉死。
盖伤寒原无定体，或入于阳，或入于阴，入阳则太阳为首，入阴则少阴为先，故传变不一，治法不同。
而其要总不越乎阴、阳、表、里、虚、实、寒、热，知八者之要，悉在浮中沈三脉有力无力中分辨之，有力者
为阳、为实、为热，无力者为阴、为虚、为寒。若能明此八字，则仲景三百九十七法，一百一十三方，了然
于胸中矣。今之治伤寒者，一二日，不问属虚、属实，便用麻黄、桂枝汤以汗之。三四日，不问在经、在府，
便用柴胡、葛根汤以和之。五六日，不问在表在里，便用承气等汤以下之。致令阴阳俱病，变症蜂起。
夫麻桂两汤，仲景专为冬月正伤寒而立也，今人乃以通治非时暴寒温暑。又将传经阴症，与夫直
中阴症，混同立论，岂不误哉。学者平时之际，须将脉症讲明，方论详审，临病之时，得心应手，则阳症
阴症之别，发汗吐下之宜，了然于心，确然无疑。又须如珠走盘，活泼泼地，见太阳症、直攻太阳，见少
阴症、直攻少阴，不可泥于始太阳、终厥阴之论。仲景曰、日数虽多，有表症而脉浮者，宜汗之。日数虽
少，有里症而脉沈者，宜下之。?乎仲景处方立论甚严，曰、可温，曰、可下，曰、与下，曰、急下，与夫先温其
里、乃攻其表，先解其表、乃攻其里，切不可执定一二日宜发汗，三四日宜和解，五六日方下。更须审
脉验症，辨府定经，一一亲切无疑，方可下手。真知其表邪而汗之，真知其直中阴经而温之，桂枝承
气，投之必差，姜附理中，发而必当，可谓得其纲领者也。
伤寒这一病症，虽然有《活人书》、《明理论》、《指掌图》、《伤寒论全生集》等书籍，但其中有的只有论述而缺少方剂，有的分类偏离了原意，有的只列脉象而没有症状描述，有的只有症状却没有治疗方法。这是为什么呢？大概是因为年代久远，遗失的内容很多，确实不是张仲景的完整原著了。后来的王叔和凭借断简残篇来补充方剂和撰写论述，成无己顺着原文进行注释并集成全书，所以遗留的祸患至今仍未停止。唉，张仲景的书失传不全，导致患伤寒病的人枉死无数。
因为伤寒原本没有固定的形态，有的侵入阳经，有的侵入阴经。侵入阳经则以太阳经为首要，侵入阴经则以少阴经为先导，所以传变情况不一，治疗方法也不同。但其要点总离不开阴、阳、表、里、虚、实、寒、热这八个方面。明白这八字的要领，完全可以在浮、中、沉三脉的有力与无力中进行分辨：脉有力属于阳、属于实、属于热；脉无力属于阴、属于虚、属于寒。如果能阐明这八字要领，那么张仲景的三百九十七种治法、一百一十三首方剂，就能在心中了然于胸了。
现在的医生治疗伤寒，一二天时，不问是虚证还是实证，就用麻黄汤、桂枝汤来发汗。三四天时，不问病在经还是在腑，就用柴胡汤、葛根汤来和解。五六天时，不问病在表还是在里，就用承气汤等方剂来攻下。致使阴阳都受病，变证蜂拥而起。
麻黄汤和桂枝汤这两首方剂，是张仲景专门为冬季感受正伤寒而设立的，现在的人却用来通治非季节性的突发寒冷、温病和暑病。又将传经而来的阴证，以及直中阴经的阴证，混同在一起立论，这难道不是错误吗？学者在平时必须将脉象和症状讲明，对方剂论述详细审察，临症之时才能得心应手，这样对于阳证和阴证的区别，发汗、催吐、攻下的适宜与否，就能心中了然，确然无疑。又须像珠子在盘中滚动一样灵活生动，见到太阳病（太阳经受邪所致的病证），就直接针对太阳经治疗；见到少阴病（少阴经受邪所致的病证），就直接针对少阴经治疗，不可拘泥于“始于太阳，终于厥阴”的固定说法。
张仲景说：“日数虽然多，如果有表证且脉象浮的，适宜用发汗法。”“日数虽然少，如果有里证且脉象沉的，适宜用攻下法。”张仲景处方立论非常严谨，说：“可用温法”，“可用下法”，“给予下法”，“紧急攻下”，以及“先温其里，再攻其表”，“先解其表，再攻其里”。切不可固执地认为一二天宜发汗，三四天宜和解，五六天才可攻下。更须审察脉象验证症状，辨别病在腑还是定在经，一一亲切确切无疑，才可以动手治疗。真正知道是表邪就发汗，真正知道是直中阴经就用温法，使用桂枝汤、承气汤，投药必定痊愈；使用干姜、附子、理中汤，用药必定恰当。这可以说是掌握了伤寒治疗的纲领了。
Shaoyang disease (disease caused by cold pathogen), although there are books such as *Huoren Shu* (Book of Those Who Survive), *Ming Lilun* (Theory of Clarification), *Zhizhang Tu* (Diagram of Palm), and *Shanghan Lun Quansheng Ji* (Complete Collection for Preserving Life in Cold Damage Treatise), among them, some have discussions but lack prescriptions, some have classifications that deviate from the original meaning, some have pulse descriptions without symptoms, and some have symptoms without treatment methods. Why is this? It is likely that due to the passage of many years, much has been lost; it is indeed not Zhang Zhongjing's complete original work. Later, Wang Shuhe supplemented prescriptions and wrote discussions based on fragmented manuscripts, and Cheng Wuji annotated the text line by line and compiled a complete book, so the lingering harm has not ceased to this day. Alas, Zhang Zhongjing's book is incomplete, leading to unjust deaths from Shaoyang disease.
Since Shaoyang disease originally has no fixed form, it may enter the Yang meridians or the Yin meridians. Entering the Yang meridians begins with Taiyang (Taiyang meridian syndrome); entering the Yin meridians begins with Shaoyin (Shaoyin meridian syndrome). Therefore, the transmission varies, and treatment methods differ. However, the essence never goes beyond Yin, Yang, Exterior, Interior, Deficiency, Excess, Cold, and Heat. Understanding the key to these eight characters allows one to distinguish them entirely through the strength or weakness of the Floating (Fu), Middle (Zhong), and Deep (Chen) pulses. A strong pulse indicates Yang, Excess, and Heat; a weak pulse indicates Yin, Deficiency, and Cold. If one can clarify these eight characters, then Zhang Zhongjing's 397 treatment methods and 113 prescriptions will be clear in one's mind.
Today, physicians treating Shaoyang disease, within one or two days, regardless of whether it is Deficiency or Excess, immediately use Mahuang Tang (Ephedra Decoction) or Guizhi Tang (Cinnamon Twig Decoction) to induce sweating. Within three or four days, regardless of whether the disease is in the Meridians or the Fu organs, they immediately use Chaihu Tang (Bupleurum Decoction) or Gegen Tang (Kudzu Decoction) to harmonize. Within five or six days, regardless of whether the disease is in the Exterior or the Interior, they immediately use Chengqi Tang (Gastrointestinal Purging Decoction) and other formulas to purge. This causes both Yin and Yang to become diseased, and complications arise like swarms of insects.
Mahuang Tang and Guizhi Tang were specifically established by Zhang Zhongjing for Zheng Shanghan (true cold damage occurring in winter). Now, people use them universally to treat sudden cold, warm diseases, and summerheat occurring out of season. Furthermore, they confuse Chuanjing Yinzheng (Yin syndromes transmitted via meridians) with Zhizhong Yinzheng (direct invasion into Yin meridians) in their discussions, which is surely erroneous. Scholars must clarify pulse and symptom patterns during their daily studies and carefully examine prescription theories. When facing a patient, they should act with ease and skill, making the distinction between Yang and Yin syndromes clear, and knowing the appropriateness of sweating, vomiting, and purging methods, leaving no doubt. They must also be flexible and lively, like a pearl rolling on a plate: seeing Taiyang syndrome, attack Taiyang directly; seeing Shaoyin syndrome, attack Shaoyin directly. Do not stick rigidly to the theory that "it starts at Taiyang and ends at Jueyin."
Zhang Zhongjing said: "Although many days have passed, if there are Exterior symptoms and the pulse is Floating, sweating is appropriate." "Although few days have passed, if there are Interior symptoms and the pulse is Deep, purging is appropriate." Zhang Zhongjing was very strict in prescribing and theorizing, stating: "Warmth may be used," "Purging may be used," "Give purging," "Urgently purge," as well as "First warm the Interior, then attack the Exterior," and "First resolve the Exterior, then attack the Interior." One must not rigidly adhere to the idea that the first one or two days require sweating, the next three or four days require harmonizing, and only after five or six days is purging allowed. One must further examine the pulse and verify symptoms, differentiate between Fu organs and determine the Meridians, ensuring every detail is clear and certain before initiating treatment. Truly knowing it is an Exterior pathogen and inducing sweat, truly knowing it is a direct invasion of Yin meridians and applying warmth, using Guizhi Tang or Chengqi Tang will surely result in recovery; using Shengjiang (Fresh Ginger), Fuzi (Prepared Aconite Root), or Lizhong Tang (Regulate the Middle Decoction) will be perfectly appropriate. This can be called mastering the general principles.