Medicine originated from Xuanyuan (Yellow Emperor) and Qibo. Initially, there was no distinction between internal medicine and surgery. This is because it stems from the theory of Five Movements and Six Qi, where the governing influence of Si Tian (Heavenly Stems controlling specific periods) leads to the shifting interactions between Zhu Qi (Principal Qi) and Ke Qi (Guest Qi). The deficiency or excess of Zang-Fu organs results in abnormal variations such as excessive pathogenic factors, depression, and rebound. The differing flavors and natures of medicinal herbs necessitate the balancing of contrary and compliant treatments, as well as correct and reverse approaches. Thus, the practitioner's role is fundamentally one and the same. However, during the Tang and Song dynasties, thirteen departments were established separately. The intention was that medical knowledge is too vast to be fully mastered by one person, encouraging individuals to specialize in a single department, much like different paths for water and land travel. Nevertheless, although sores and ulcers are termed "external medicine," their root cause must lie within the interior. Furthermore, they often involve techniques such as acupuncture to remove necrotic tissue and promote muscle regeneration, suggesting that treating the exterior might be more difficult than treating the interior. In recent times, those who value internal medicine while despising external medicine do so because contemporary physicians abandon internal medical principles to treat external diseases, which is abandoning the root to follow the branch. During my leisure time, I exerted utmost effort to collect and select materials, delving into the profound principles of *Suwen* (Basic Questions) and *Lingshu* (Spiritual Pivot), and gathering definitive discussions from famous sages of ancient and modern times, compiling them into a single book titled *Waike Dacheng* (Great Completeness of Surgery). It directly states the relationship between root and branch, making it clear at a glance, just as stars have their orbital degrees and the Milky Way has its source and flow, hopefully preventing human life from being treated as lightly as worthless grass. Now that *Waike Dacheng* has been printed, a rough commentary on the diagnosis and treatment of internal medicine symptoms will be published subsequently. Therefore, I record my past observations as this postscript.
Qin Kun, styled Kuisheng Yangzi, wrote the postscript.