Library

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).