Zhuangzi said, "Do good without seeking fame; do no evil to avoid punishment." In this way, one can serve one's parents, nourish one's life, and fulfill one's natural lifespan. This seems to refer specifically to medicine. My family has relied on this profession for generations as a means of serving our parents and preserving our health, thereby perhaps avoiding the burdens of seeking fame or incurring punishment. Although I am not certain whether Zhuangzi's words were intended to describe medicine, observing my own family's experience, it is evident that medicine indeed bears resemblance to Zhuangzi's teachings. Mr. Cao Luzhai, an official of the Ministry of Justice (Bubu), remained tranquil in his official career but had a particular fondness for medical texts. His meticulous and arduous proofreading efforts surpassed those of us lesser scholars. This book is voluminous; due to long-standing transmission and copying, errors and omissions account for nearly half of the text. Without Mr. Cao, this work would hardly have been completed. Did Mr. Cao disdain high office yet place great importance on the title of "physician"? As for nourishing life and fulfilling one's natural span, the benefits gained from a career in officialdom versus reclusion in the mountains and forests are incomparable. Postscript by Shao Bian, courtesy name Weiyuan, of Xuansha.