Library

The works of Master Zhu Danxi are recited and studied by the world, such as *Gezhi Yulun* (Supplement to Discourses on Investigation of Things), *Jufang Fahui* (Elucidation of the Formulary), *Shanghan Biyi* (Doubts on Cold Damage Clarified), *Bencao Yan Yi Bu Yi* (Supplement to the Extended Meaning of Materia Medica) and other collections. Since they have been listed among the great masters like Zhang Yuansu and Liu Wansu, no one dares to interject. Only the volume titled *Shoujing* (Hand Mirror) was kept secret and cherished by the Master; he carried it with him wherever he traveled, often holding it close, and did not lightly show it to others. Nearly three hundred years have passed since then. Those within the realm who are eager to see this book regard it as if it were the forbidden prescriptions mentioned by Chang Sangjun and Yang Qing—difficult to obtain—and believe it is perhaps not of this world. I once remarked that Wu Gong, the Prefect of Wu, obtained it from his descendants. Could there be a sign for the emergence of a divine artifact? The Master's descendants experienced several cycles of rise and fall, but they merely kept the book secret, warning each other not to leak it, without being able to promote or publicize it. Thus, there were often regrets over textual errors. Wu Gong therefore collated and corrected them one by one and ordered them to be carved into blocks for widespread dissemination. I was fortunate enough to complete my study of it. Its language is concise and plain, yet its meaning is profound and extensive. It penetrates the viscera and yin-yang of the human body and formulates remedies accordingly. Often, within single words or short phrases, it hits the mark miraculously. However, its main principles originate from the words of the Yellow Emperor, and it does not speak unless it is based on the *Suwen* (Basic Questions). During the previous dynasty (Yuan), Chen Shiwen and Pei Zongyuan promulgated 297 formulas in the *Daguan* era, leading to the prevalence of the "Formulary School." Master Danxi stood alone...

According to *Diwang Shiji* (Chronicle of Emperors), Shennong used a jujube-colored whip to strike plants and trees, examining their neutral and toxic properties, highlighting their drying and cold natures, investigating their mutual aversions and incompatibilities, distinguishing their ministerial and auxiliary roles, organizing and correcting them. Within a single day, he encountered more than seventy types of toxins, exhausting all things containing qi. There were four hundred diseases of humans and two hundred sixty-five medicinal substances, thus composing the *Bencao* (Materia Medica), and the origin of medical texts was opened. The Yellow Emperor deeply worried about premature death, confusion, disasters, and plagues among people. He explored from the heavens to the earth, observed the Five Qi to establish the Five Movements, penetrated life and nature, recorded yin and yang, and urgently consulted Qibo and Leigong, resulting in the creation of the *Neijing* (Inner Canon). Below the *Neijing*, those stored in government offices numbered 179 authors, 209 sections, and 1,259 volumes, excluding later miscellaneous writings. Although the *Neijing* is attributed to the Yellow Emperor and was likely fabricated by scholars of the Pre-Qin period based on imitation, its language is simple and profound, and its meaning is vast and deep. It is truly the guiding principle of medicine, just as the Six Classics are for Confucianism.
Qin Yueren's *Nanjing* (Classic of Difficult Issues, 81 Chapters) followed, presumably taking the essential points of the Yellow Emperor and Qibo and elaborating upon them, ranking second only to the *Neijing*. Zhang Zhongjing of the Han Dynasty, based on the principles of the *Neijing* and *Nanjing*, wrote the *Jingui Yufan Jing* (Golden Cabinet Jade Box Classic) and various treatises on *Shanghan* (Cold Damage). His discussion on the injuries caused by the Six Qi is the most detailed and comprehensive. Wang Shuhe of the Jin Dynasty compiled the books of Qibo, Hua Tuo, etc., into the *Maijing* (Pulse Classic), describing yin and yang, internal and external, differentiating the Three Regions and Nine Pulses, systematically detailing the Twelve Meridians, and particularly providing precise descriptions of diseases of the Sanjiao, Five Zang, and Six Fu organs. The works of these two schools are indeed classics that cannot be altered for millennia. Later, Chao Yuanfang wrote the *Bingyuan Houlun* (Treatise on Pathogenesis and Manifestations of Diseases), and Wang Bing wrote the *Tianyuan Yuce* (Jade Strategy of Heavenly Origin). Both generally inherited and expounded upon previous works. However, Chao Yuanfang discussed wind, cold, and dampness but did not mention damp-heat. Wang Bing deduced the changes of the Five Movements and Six Qi, attributing illness to stagnation and blockage; this was their flaw. When Sun Simiao emerged in the Tang Dynasty, with extraordinary insight and sincere benevolence to benefit all beings, he compiled the *Qianjin Fang* (Prescriptions Worth a Thousand Gold) and its supplement. By promoting past sayings and enlightening future students, he made profound contributions to the medical way. At that time, Wang Tao had the *Waitai Miyao* (Essential Prescriptions from the Imperial Library), which described formulas, indications, acupuncture points, moxibustion, and cautery in great detail. However, his claim that acupuncture can kill living people but cannot revive the dead is a biased argument. When Qian Yi, Pang Anchang, and Xu Shuwu rose successively in the Song Dynasty, Pang Anchang was confined within rigid standards, while Xu Shuwao focused on unexpected maneuvers and adaptability. Their techniques were all based on Zhang Zhongjing. Only Qian Yi deeply mastered the mysteries of Zhang Zhongjing, establishing formulas for the Five Zang organs according to their specific needs, stating that since the Liver contains Ministerial Fire, it should be purged rather than tonified, and since the Kidney is True Water, it should be tonified rather than purged. This can be said to have unlocked the secrets of the *Neijing*. Unfortunately, his remaining works were scattered and lost; what exists was collected by Yan Zhongxiao and is not the true essence of Qian Yi. As for the 297 formulas created by Chen Shiwen and Pei Yuanzong during the Daguan era, attempting to use fixed formulas to respond to infinite diseases, those with insight certainly knew they lacked understanding of flexibility and adaptation. When the Jin clan occupied the Central Plains, Zhang Congzheng (Zhang Jiegu), Liu Wansu (Liu Shouzhen), Zhang Yuhe, and Li Gao (Li Mingzhi) arose, and the medical way was revitalized. Zhang Jiegu treated diseases without relying on fixed formulas, so his books were not transmitted. His learning was deeply understood by Li Mingzhi. Li Mingzhi analyzed internal and external injuries, prioritizing the treatment of Spleen and Earth. His method specialized in tonification, and his work *Piwei Lun* (Treatise on the Spleen and Stomach) is indeed a fundamental text. Zhang Yuhe considered the three methods of vomiting, sweating, and purging, and the six categories of wind, cold, summer-heat, dampness, dryness, and fire as the keys to medicine. His prescriptions were mostly harsh, and his method focused on attack. Liu Shouzhen discussed wind and fire diseases, basing his *Yuanbing Shi* (Original Causes of Disease) on the Nineteen Pathogenic Mechanisms and Qi Suitabilities from the *Neijing*, capturing subtleties with precision. His therapeutic methods were similar to those of Zhang Yuhe. After two generations, the lineage of the Zhang school faded. Li's disciples were mostly in the Central Plains. Only Liu's teachings were passed down to the Buddhist monk from Jingshan. The monk went to Jiangnan and passed them to Song Zhongren and Luo Zhili, after which all doctors in the South revered them. In the Yuan Dynasty, those discussing medicine did not speak unless it was the Liu school's learning. Although the methods of Liu and Li differed in attack and tonification, the one who could integrate and illuminate them spiritually was Danxi; the one who researched them precisely and transformed and adjusted them was Danxi's books. Upward continuing the legitimate line of the imperial family, downward extending the distant flow of the Ji River, this person and this book—I do not know where their end lies.
In the year of Tianqi, during the month of Zhuangyue on the Tianyi day, Wu Kai, courtesy name Maorenfu, a scholar from Wanjing, composed this account.