Why is it that physicians still value medical cases? What is valued in medical cases is the prescription; what is essential in prescriptions is efficacy. A medical case involves reasoning and methodology: investigating the etiology, detailing the syndrome patterns, and making a therapeutic judgment. A prescription consists of sovereign (Jun), ministerial (Chen) herbs, orthodox (Zheng) and counteracting (Fan) treatments, odd (Qi) and even (Ou) formulas. It addresses pathogenic excesses, eliminates bodily imbalances, and maintains equilibrium. Equilibrium constitutes cure, and cure signifies recovery.

Since the time of Zhang Zhongjing (the Prefect of Changsha), renowned sages have been as numerous as fish in a stream, and their writings are too many to count one by one. To this day, readers do not have the leisure to even list their titles, let alone discuss their contents! Even when discussing these theories, each adheres to a single viewpoint; those proficient in one area disparage another, and proponents of one method enslave themselves to another. The language is verbose and repetitive, with chapters duplicating simple concepts. What could be summarized in a few words takes volumes to exhaust. Although the brilliant phrases may captivate the senses, they merely advocate empty talk without benefiting practical application. Theories cannot guarantee utility, and applications cannot guarantee efficacy. This only bewilders learners, causing them to hesitate on the wrong path. As the saying goes, "To believe everything in books is better than having no books at all." With life being finite and learning infinite, few can avoid peril. Seeking simplicity through breadth, and ensuring claims are credible and verifiable, medical cases are paramount. The creation of medical cases involves seeking etiology from symptoms, seeking treatment from etiology, formulating prescriptions based on treatment, and observing efficacy through prescriptions. Their efficacy is as immediate as a drum responding to a beat; their lack of efficacy is as evident as an eclipse of the sun or moon. They cannot be dismissed with empty words or sustained by mere rhetoric. Later learners, following the map to find the horse, step by step emulate, modifying established methods and integrating novel ideas. Following rules to create shapes, inferring three corners from one, their utility is broad and their effects prominent.

Among excellent medical cases, the Qing Dynasty is foremost, with figures such as Xu Lingtai, You Zaijing, Ye Tianshi, and Xue Shengbai, each possessing specialized expertise. I studied family-transmitted texts, regarding them as precious secrets. However, those proficient in one aspect are often clumsy in others; those addicted to tonification find attack methods difficult. This is perhaps what is meant by "specialization allows for depth, but mastering all virtues is hard." Mr. Ding Ganren, originating from Menghe—a place indeed famous for many physicians—absorbed the essence he observed with his eyes and ears, further tracing back to ancient masters, thoroughly researching profound principles, melting the ancient into the modern, excelling in both internal and external medicine. There was no disease he could not treat, nor any treatment that did not result in recovery. Practicing in Shanghai, he wore out the thresholds of his door. Society praised him as a skilled artisan, and the medical community acknowledged him as a giant. Having the privilege to attend lectures and receive guidance, I was mistakenly regarded as a confidant, our relationship akin to brothers, advancing from friend to teacher. Through mutual polishing and discussion, I benefited immensely. Alas, benevolent people do not always enjoy longevity. Mr. suddenly passed away, his horse's head became impossible to follow, and help from other mountains was unavailable. This is why Shaoting sighs and sheds tears. Now, Mr.'s literary grandson, Jiwan, has faithfully inherited his grandfather's will, collecting and editing his remaining cases into a book. This serves to provide material for later learners to observe and emulate, and to serve as a mirror for colleagues. The intention is most virtuous. Disregarding my unworthiness, you asked me for a preface. Ashamed of my lack of scholarship, I feel inadequate to write a preface for Mr. However, given how significant medical cases are to the medical way, and knowing that Mr.'s scholarship is deeply understood by Shaoting, the benefit of this compilation to colleagues and future learners needs neither candlelight inspection nor tortoise shell divination to be known. Thus, this preface.
Written respectfully by Xia Shaoting in the winter month of the Dingmao year.