Medicines possess ten characteristics: dispersing (Xuan), unblocking (Tong), tonifying (Bu), purging (Xie), lightening (Qing), heavy/sedating (Zhong), slipping/lubricating (Hua), astringent (Se), drying (Zao), and moistening (Shi). These constitute the general principles and major laws of materia medica, and therapeutic interventions do not extend beyond this scope. Comprehending the application of these ten properties, combined with the three methods of cold, heat, and warmth, is sufficient to rival the thirteen chapters of *The Art of War* by Sun Tzu. One who can master these thirteen methods will win every battle and achieve efficacy in every cure; is it not that while the affairs differ, the underlying spirit is the same? This was not elaborated upon in the *Shennong Bencao Jing* (Divine Farmer's Materia Medica), nor deeply expounded by later generations; therefore, many are confused regarding the compounding of decoctions and pills. Now that I have brought this to light, those engaged in medicine should understand its categorization and emulate its application, thereby fully exhausting the way of treatment.

It is said: "Ancient formulas cannot treat modern diseases." Alas! This is an exaggeration. I maintain that the *Tai Ping Hui Min He Ji Ju Fang* (Imperial Bureau of Medicine Formulary), with Zhu Danxi expounding upon it earlier and Dai Yuanli succeeding him later, has done no disservice to people through the use of ancient formulas. The issue lies merely in the practitioner's failure to apply them appropriately. Although there may be cases where the syndrome does not perfectly match the formula, the wise approach is to adjust the dosage and ingredients based on the variations of the syndrome; this is the best of the best. Why must one abruptly reject ancient formulas? Alas! This is also an exaggeration. Thus it is said: Clinging to ancient formulas for treatment is called being rigid/stuck (Ni); abandoning ancient formulas for treatment is called being arbitrary/forced (Zao). Both rigidity and arbitrariness are incorrect. Only by flexibly adding or subtracting according to suitability—what is termed "transforming and adjusting"—can one achieve adaptability (Tong).

Wenke Gong of Zhenze stated: "Contemporary physicians revere Li Dongyuan (Li Mingzhi) and Zhu Zhenheng (Zhu Yanxiu). Their prescriptions rarely go beyond herbs like Ginseng (Renshen) and Atractylodes Macrocephala (Baizhu). This can be considered the 'Kingly Way' of medicine, truly rooted in fundamental principles. However, since diseases arise from changes, herbs such as Ginseng and Atractylodes may not always be effective; thus, medicinal strategies must also change. If one knows that change is possible but fails to change, one sits waiting for demise; if one changes but errs by a hair's breadth, one may hasten death. Both scenarios are unacceptable. Hence it is said: 'One can establish principles with another, but one cannot necessarily engage in discretionary adaptation (Quan).' If a physician can exercise discretion in prescribing, this can be called profound. Li Dongyuan and Zhu Zhenheng did not abandon discretion; rather, contemporary physicians follow routine without learning adaptation. Is it not difficult to employ discretion?" (From *Zhenze Wenji*)