宋景濂云古之医师必通于三世之书所谓三世者一曰针灸二曰神农本草三曰素问脉经脉经
所以
察证本草所以辩药针灸所以祛疾非是三者不足以言医故记礼者有云医不三世不服其药而传经
者乃以父子相承为三世何其惑欤噫古之豪杰自振者不能悉举若李东垣朱丹溪滑伯仁辈皆非世
传而精造医术屡起危殆着书立言为后学楷范初不闻其父子相传也是知医在读书而不在于三世
明矣
王忠文公( )云李明之弟子多在中州独刘守真之学传之荆山浮图师师至江南传之 中
人罗知悌而南方之医皆宗之矣及
国朝天下之言医者非刘氏之学弗道也刘李之法虽攻补不同会而通之随症而用之不行其存
乎近
时吾吴中称良医师则以能持东垣者谓之王持张刘者谓之伯噫尧舜以揖让汤武以干戈苟合道济
世何必曰同余尝病世之专于攻伐者邪气未退而真气先满然矣专于补养者或致气道壅塞为祸不
少正气未复而邪气愈炽矣古人有云药贵合宜法当应变泥其常者人参反以杀人通其变者乌头可
以活命孙真人所谓随时增损物无定方真知言哉
葛震父云为医当视时之盛衰刘守真张子和辈值金人强盛民悍气刚故多用宣泄之法及其衰
也兵革
之余饥馑相仍民劳志苦故张洁古李东垣辈多加补益之功至若宋之季年医者大抵务守护元气而
不识攻伐之机能养病而不能治病其失在于不知通变也王好古云大定间医者用防风通圣散盛行
于世而多效何哉虽市井之徒口腹备衣服全心志乐而形不苦是以多效而少失或遇扰攘之世饥馑
之年HT 盐糟糠犹不能充况加以值天地肃杀之运岂可一例用凉药如承平之时丰稔之岁哉殊不知
张仲景用桂枝于当汉之末韩祗和则戒用桂枝于当宋之隆此亦因时而用药者也
宋濂说：古代的医师必须精通“三世”之书。所谓“三世”，一是《针灸》（针灸疗法），二是《神农本草经》（药物学著作），三是《素问》与《脉经》（中医基础理论与诊断学著作）。《素问》用来观察证候，《本草经》用来辨别药性，《针灸》用来祛除疾病。不具备这三者，就不足以称为医生。所以《礼记》中有记载：“医不三世，不服其药。”而传承经典的人却把父子相承称为“三世”，这多么令人困惑啊！唉，古代那些豪杰之士自我振奋的，不能一一列举。像李东垣、朱丹溪、滑伯仁这些人，都不是世代相传的家学，却能精深造诣于医术，屡次挽救危重病人，著书立说成为后学的楷模，起初也没听说他们是父子相传的。由此可知，医学关键在于读书学习，而不在于是否遵循“三世”家传，这是很明显的了。
王忠文公说：李明之（李杲）的弟子大多在中州地区，唯独刘守真（刘完素）的学问在荆山浮图处师师相传，一直传到江南，再传给罗知悌，南方的医生都尊崇他的学说。到了本朝，天下谈论医学的人，如果不提及刘氏的学说就不算说话。刘完素与李东垣的治疗方法虽然攻邪与补虚不同，但若能融会贯通，随症施用，就不会有问题。至于当今我们吴中地区称颂良医时，凡是能运用李东垣学说的，被称为“王”（指王好古等继承者）；凡是能运用张元素、刘完素学说的，被称为“伯”。唉，尧舜以禅让治国，商汤周武以征伐取天下，只要合乎大道、救济世人，何必说方法相同呢？我曾经批评世上那些专事攻伐的人，邪气尚未退去，真气先已亏损殆尽；专事补养的人，有时会导致气机壅塞，造成的祸患不少，正气未恢复而邪气更炽盛。古人有话说：用药贵在适宜，治法应当应变。拘泥于常规，人参反而可能杀人；通晓变化，乌头也可以救命。孙思邈所说的“随时增减，事物没有固定的方剂”，真是深知此理的话啊。
葛震父说：行医应当观察时势的盛衰。刘完素、张子和等人处于金国强盛、百姓强悍、气质刚烈的时期，所以多用宣泄的方法；等到金国衰败时，战乱之后，饥荒接连不断，百姓劳苦，志向困苦，所以张洁古、李东垣等人多加用补益之功。至于宋朝末年，医生大抵致力于守护元气，而不识攻伐的功效，只能养护病人而不能治愈疾病，他们的失误在于不懂得变通。王好古说：大定年间，医生使用防风通圣散盛行于世且多有效验，为什么呢？因为当时市井之徒衣食无忧，心志安乐，形体不受苦楚，所以多有效验而少失误。如果遇到动荡混乱的时代、饥荒之年，连粗劣的食物尚且不能吃饱，何况再加上天地肃杀的气运，怎么能一概使用寒凉药物，就像太平盛世、丰收之年那样呢？殊不知，张仲景在汉朝末年使用桂枝汤，韩祗和在宋朝兴盛时期则告诫慎用桂枝汤，这也是因时制宜用药的例子。
Song Lian said: Ancient physicians must be proficient in the "Three Generations" of books. By "Three Generations," it is meant: first, *Zhenjiu* (Acupuncture and Moxibustion); second, *Shennong Bencao Jing* (Divine Farmer's Materia Medica); third, *Suwen* (Basic Questions) and *Maijing* (Pulse Classic). *Suwen* is used to observe syndromes; *Bencao Jing* is used to distinguish medicinal properties; *Zhenjiu* is used to dispel diseases. Without these three, one cannot claim to be a physician. Therefore, *Liji* (Book of Rites) states: "If a physician has not practiced for three generations, do not take their medicine." However, those who transmit scriptures mistakenly equate father-to-son succession with "three generations," which is highly confusing. Alas, heroes of antiquity who stood on their own feet cannot all be listed. Figures such as Li Dongyuan, Zhu Danxi, and Hua Bolin were not products of hereditary family lineages, yet they achieved profound mastery in medical arts, repeatedly saving critical patients, and established writings that served as models for later learners. It was never heard that they passed knowledge solely from father to son. Thus, it is evident that medicine lies in reading and learning, not merely in adhering to the "three generations" of family tradition.
Lord Wang Zhongwen stated: Most disciples of Li Mingzhi (Li Gao) were located in the Central Plains. Only the teachings of Liu Shouzhen (Liu Wansu) were transmitted master-to-master from Jing Shan Futu to Jiangnan, and then passed to Luo Zhitie. Physicians in the south all revered his school. In our dynasty, anyone discussing medicine without mentioning the Liu school was considered incomplete. Although the methods of Liu Wansu (emphasizing clearing heat/purging) and Li Dongyuan (emphasizing tonifying) differ in approach—attacking versus supplementing—if one integrates them and applies them according to symptoms, there will be no error. As for the good physicians praised in our Wu region today, those who skillfully employ the Dongyuan method are called "Wang" (referring to successors like Wang Haogu), and those who employ the Zhang-Liu methods are called "Bo." Alas, Yao and Shun ruled by abdication, while Tang and Wu conquered by warfare; as long as one aligns with the Dao and saves the world, why insist on identical methods? I have criticized those in the world who specialize in attacking pathogens: before the evil qi recedes, the healthy qi may already be depleted. Those who specialize in nourishing and tonifying may cause qi stagnation and blockage, resulting in significant harm; the healthy qi fails to recover while the evil qi becomes more rampant. The ancients said: Medicines should be appropriate, and methods should adapt to changes. Clinging to conventions, even Ginseng (*Ren Shen*) can kill; understanding flexibility, even Aconite (*Wu Tou*) can save lives. Sun Simiao’s statement that "dosages should increase or decrease according to the times, and things have no fixed formulas" truly reflects deep understanding.
Ge Zhenfu said: Practicing medicine requires observing the prosperity or decline of the times. Liu Wansu and Zhang Zihe lived during the rise of the Jin Dynasty, when people were robust and their constitutions strong; thus, they frequently used purgative and dispersing methods. When the Jin Dynasty declined, following wars and continuous famines, the people were exhausted and suffering; therefore, Zhang Jiegu and Li Dongyuan focused heavily on tonification and supplementation. By the late Song Dynasty, physicians mostly aimed to protect the primordial qi, lacking knowledge of attack-and-purge techniques; they could sustain patients but not cure diseases. Their failure lay in not knowing how to adapt. Wang Haogu stated: During the Dading era, the use of *Fangfeng Tongsheng San* (Saposhnikia Decoction for Unblocking the Supreme) was prevalent and effective. Why? Because commoners had sufficient food and clothing, their minds were at ease, and their bodies were not afflicted, leading to high efficacy and few errors. However, in turbulent times or years of famine, when even coarse grains are scarce, let alone facing the harsh influences of heaven and earth, how can one uniformly apply cold-cooling medicines as in peaceful, abundant years? One must realize that Zhang Zhongjing used *Guizhi Tang* (Cinnamon Twig Decoction) at the end of the Han Dynasty, whereas Han Zhihe warned against using *Guizhi Tang* during the peak of the Song Dynasty. This illustrates prescribing medications according to the times.