Library

The *Book of Documents* states: "If the medicine does not induce a state of dizziness or nausea (mingxuan), the severe disease will not be cured." The *Rites of Zhou* records: "The Physician-in-Chief is in charge of medical administration, collects toxic substances, and jointly handles medical affairs." From this, we can see that medicines possess toxicity/potency, and diseases are caused by pathogenic factors (often conceptualized as 'poison' or extreme imbalance). Using the potency of medicine to attack the pathogenic factor is what induces the mingxuan reaction. However, upon examining the *Bencao* (Materia Medica), some herbs are potent/toxic, while others are not; some have nourishing properties, while others do not. Consequently, people are greatly confused. Due to the passage of time, ancient sages have passed away, and classics have been destroyed; although one wishes to correct these errors, there is no way to do so. What remains reliable today is only Heaven, Earth, and Humanity.

With Heaven and Earth come all things; with all things comes the capacity for potency/toxicity; with humanity come illness and health. This is a constant shared by both ancient and modern times. By adhering to these constants, one can correct the deviations; if so, what cannot be corrected? The method of Bian Que is used to test prescriptions: when medicine induces mingxuan, the severe disease is cured. As for whether herbs are "nourishing" or "non-nourishing" as claimed in the *Bencao*, such claims ultimately lack verification. Therefore, I have followed the method of Bian Que to test prescriptions for forty years. By measuring the dosage, I have determined their primary indications; by observing the location of the disease, I have identified their secondary indications. Through mutual cross-referencing and examination, I have clarified the specific signs (indications) of the herbs. Thus, my initial confusion has become clear and distinct.

Generally speaking, the tools for attacking disease are all potent (toxic); this is the duty of the Clinician (Jiyi). The preparations for preserving essence require distinguishing between potent and non-potent substances; this is the duty of the Dietitian (Shiyi). Food represents the normal state, while disease represents deviation. We, the younger generation, must distinguish between the normal and the deviant, and not confuse them. However, the *Bencao* confuses them into one, which is why it should not be adopted. Since the *Bencao* is not to be adopted, reliance must be placed on prescriptions. Standards and rules are established by using the method of Bian Que to verify the efficacy of prescriptions and to examine precisely what symptoms each herb primarily treats. Next, I list the evidence from examinations to substantiate these primary indications. Then, for prescriptions lacking such evidence, I cross-reference and arrange them, citing ancient knowledge to辨析 (analyze and distinguish) those instances where ancient and modern misunderstandings of herbal efficacy have occurred. Finally, I list various substances to distinguish authenticity from falsehood, naming this work *Yao Zheng* (Evidence of Medicines).

Consider a single substance: if its use differs, its efficacy differs. Therefore, those who practice health preservation follow personal preferences and aversions; those who treat disease do not avoid personal preferences or aversions. Thus, the way of the Dietitian focuses on preserving essence, classifying herbs by potency and selecting them according to preference. The way of the Clinician focuses on attacking disease; therefore, any potent herb is usable, regardless of preference. If physicians fail to distinguish between these roles and confuse them, the clinical approach will perish.

What remains unchanged between ancient and modern times is Heaven, Earth, and Humanity. What changes is the theoretical discourse. Using the unchanging to correct the changing means that the unchanging remains unchanging, and the changing remains changing. It is like a ruler employing talent: utilizing ability yields merit, understanding capability yields achievement. A single substance does not have different efficacies inherently, but different uses yield different results. Is it used for health preservation? Or for treating disease? Health preservation follows preferences; treating disease does not shy away from preferences. Without knowing this method, how can one attain correctness? Once the method is established, one uses the unchanging facts to correct the changing theories. The *Classic of Poetry* says: "Chopping the handle, chopping the handle, the pattern is not far away." This refers to the present situation.

Currently, medical theorists discuss herbs based on Yin-Yang and Five Elements theory, whereas clinicians discuss herbs solely based on their efficacy. Thus, the unchanging remains unchanging, and the changing remains changing. So, how should disease be treated? It cannot be conquered without attacking. How should health be preserved? It cannot be achieved without following nature. Let us, the younger scholars, not be dazzled by theoretical discourses, thereby losing sight of practical efficacy.

Written by Yoshitsugu Katsuragawa of Edo, Japan, during the Mid-Autumn Festival of the 8th year of Meowa.