孟子言梓匠轮舆。能与人规矩。不能与人巧。巧者何。变通之谓也。巧固不能使人。其
实不出规矩。人可即规矩以求巧。而巧自无方。是亦不啻使之矣。医之道将毋同。自古迄今
医书多不胜纪。一病必立一门。一门必立数法。究之法有尽。病无尽。一病之变已无尽。
或萃数病于一人之身。其更改无尽。医之法于是乎几穷。盖以法也者。不过梓匠轮舆之规矩
病不根据规矩以为患。医第循规矩以为治。常者生焉。变者死焉。转恨医之法未备也。不知
法岂能备。要在乎用法者之巧耳。闻之名医能审一病之变。与数病之变。而曲折以赴之。操
纵于规矩之中。神明于规矩之外。靡不随手而应。始信法有尽。而用法者之巧无尽也。成案
甚伙。医之法在是。法之巧亦在是。尽可揣摩。惜向来刊行医案。醇疵互收。一为去取而巧
者愈见。此予所以复有古今医案之选也。惟是彼之所谓巧者。自今视之。犹规矩也。倘执巧
以为巧。而不更加变通。则巧反成拙。故予于每条下。妄据鄙见以按之。辨其真伪。别其是
非。晰其同中之异。表其青出于蓝。或综数事为数语。以 括其大略。或纂述旧说新说
补诸案之未逮。随选随录。随录随按。不惮烦词。窃附举隅之意。第恐载籍极博。见闻有限
譬诸审曲面势者。能免斫而小之之讥乎。然欲求巧于规矩。敢不择材以削HT 。爰自甲午冬
月。为捉笔之始。至戊戌春月。乃得蒇事。时年已七十。阅历既多。或片词之可取。爰付剞
劂。质之海内诸同志。
乾隆四十三年岁在着雍奄茂之 月既望惺斋俞震书于酌古堂
孟子说，木匠和车工（梓匠轮舆：指工匠），能把规矩法度教给别人，但不能把灵巧的技巧直接传授给别人。所谓的“巧”，就是灵活变通的意思。灵巧固然不能凭空使人获得，但其根本原理并未超出规矩的范围。人们可以依据规矩去追求灵巧，而灵巧本身是没有固定模式的，这也就相当于教会了别人。医学的道理大概也是如此。从古至今，医书多得数不胜数，一种疾病必然设立一个门类，一个门类必然包含多种治法。然而究其根本，治法是有限的，而疾病是无限的；一种疾病的演变也是无穷无尽的。有时几种疾病同时出现在一个人身上，其变化更是无穷无尽。医生的治法因此几乎陷入困境。这是因为治法，不过就像工匠的规矩一样。如果疾病不按照常理发生，医生只是机械地遵循规矩来治疗，那么符合常理的病就能痊愈，出现变化的病就会死亡。人们反而怨恨医生的治法不够完备。却不知道治法怎么可能完备呢？关键在于运用治法的人是否具备“巧”罢了。我听说名医能够洞察一种疾病的演变，以及多种疾病并发的演变，从而曲折周详地去应对，在规矩之中操控自如，在规矩之外神妙莫测，没有不随手应验的。这才相信治法是有限的，而运用治法者的灵巧是无穷的。成型的医案非常多，医生的治法就在这里，治法的灵巧也在这里。完全可以从中揣摩学习。可惜以往刊行的医案，精华与瑕疵混杂收录。一旦经过筛选取舍，那些运用得巧妙的地方就更加显现出来。这就是我重新编选《古今医案按》的原因。只是，他们所谓的“巧”，从今天的视角来看，依然属于规矩的范畴。如果执着于这种“巧”而不再加以变通，那么“巧”反而会变成“拙”。所以我对于每一条医案，都冒昧地根据我的浅见进行按语评论。辨别其中的真伪，区分是非，阐明相同之中的差异，表彰那些青出于蓝的案例；或者综合几件事写成几句话，以概括其大略；或者汇编旧说与新说，补充各医案的不足之处。随着选择而记录，随着记录而评论，不怕言辞繁琐，私下里怀着举一反三的意思。只是担心典籍极其广博，而个人的见闻有限，就像审视木材曲直形状的人，难道能避免被嘲笑砍削不当吗？然而想要在规矩中求得灵巧，怎敢不精心选材并进行雕琢呢？于是从甲午年冬天开始动笔，到戊戌年春天才完成此事。当时我已经七十岁了，阅历丰富，或许其中有些片言只语值得采纳，于是交付刻印，向海内各位同道请教。
乾隆四十三年岁次癸卯（着雍奄茂）某月十六日（既望），惺斋俞震在酌古堂书写。
Mencius stated that carpenters and wheelwrights (Zijiang Luyu: referring to craftsmen) can teach others the compass and square (Guiju: standards and rules), but they cannot impart dexterity (Qiao: skillful adaptability) directly. What is meant by "dexterity"? It refers to flexible adaptation. Although dexterity itself cannot be bestowed upon someone, its essence does not exceed the scope of the compass and square. One may seek dexterity by adhering to the compass and square, yet dexterity has no fixed form; this is akin to teaching them. The way of medicine is likely similar. From ancient times to the present, medical texts are too numerous to record. For every disease, a specific category must be established; for every category, several methods must be established. Ultimately, however, methods are finite, while diseases are infinite; the variations of a single disease are also endless. Sometimes, multiple diseases converge on one person, leading to endless changes. Consequently, the physician's methods seem nearly exhausted. This is because medical methods are merely like the compass and square of craftsmen. If a disease does not manifest according to standard patterns, and the physician merely follows these standard rules for treatment, those following the norm will survive, while those exhibiting variations will die. People then regret that physicians' methods are insufficient. They fail to realize that how could methods ever be complete? The key lies in the dexterity of the practitioner. I have heard that renowned physicians can discern the variations of a single disease or the concurrent variations of multiple diseases, responding with nuanced precision. They operate within the bounds of the rules while achieving spiritual mastery beyond them, ensuring immediate efficacy in every case. Only then can one believe that methods are finite, but the dexterity of the practitioner is infinite. There are many completed medical cases (Anli: recorded clinical cases); the physician's methods reside here, and the dexterity of these methods resides here as well. They offer ample material for study and imitation. Unfortunately, previously published medical cases often mix essence and flaws indiscriminately. Once selected and filtered, the instances of dexterity become even more apparent. This is why I undertook the selection of *Gujin Yi'an An* (Classical and Modern Medical Cases with Annotations). However, what they considered "dexterity" appears, from today's perspective, still bound by routine rules. If one clings to such "dexterity" without further adaptation, "dexterity" may turn into clumsiness. Therefore, for each case, I have presumptuously added annotations based on my humble opinions. I distinguish truth from falsehood, clarify right from wrong, elucidate differences within similarities, and highlight cases where the student surpasses the master. I sometimes synthesize several events into a few sentences to summarize the gist, or compile old and new theories to supplement the deficiencies of various cases. I select and record, record and annotate, sparing no verbosity, privately intending to illustrate the general principle through specific examples. Yet, fearing that the literature is vast while my knowledge is limited, I wonder if, like a craftsman examining the grain and shape of wood, I can avoid criticism for improper carving. Nevertheless, seeking dexterity within the rules, how dare I not select fine materials and carve carefully? Thus, I began writing in the winter of the Jiawu year and completed the work in the spring of the Wuxu year. By then, I was already seventy years old. With extensive experience, perhaps some fragments are worth preserving. I therefore submitted them to the printer to present to learned colleagues throughout the land.
Written by Yu Zhen of Xingzhai at Zhuogu Hall on the 16th day of [Month] in the Gui-Mao year (43rd year of Qianlong).