Someone questioned me, saying: Pulse diagnosis is categorized into Seven Exterior (Qi Biao), Eight Interior (Ba Li), and Nine Channels (Jiu Dao), yet there is no mention of Wiry (Xian), Hooked (Gou), Hairy (Mao), or Stony (Shi) pulses. Why do medical texts state that the spring pulse is Wiry, summer is Hooked, autumn is Hairy, and winter is Stony? Moreover, what is the rationale behind this? I replied: This concerns the principle of the ascending and descending of Yin and Yang; Heaven, Earth, and Humanity (San Cai) all originate from the Supreme Ultimate (Taiji). The spring pulse being Wiry refers to the Liver pulse, which is interiorly-exteriorly related to the Gallbladder. Yang Qi ascends from the earth; at this time, its energy is still subtle, residing between the exterior and interior. Therefore, the qi comes forth soft and weak, light and void, smooth, straight, and long, hence it is called "Wiry." The summer pulse being Hooked signifies the peak of Yang and the birth of Yin. The character "Hook" originally denotes a shape that is large at the head and small at the tail. At the Summer Solstice, Yin is born. During summer, the six Yang energies fully ascend; the pulse arrives strongly but departs weakly, hence it is called "Hooked." The autumn pulse being Hairy: the character "Mao" is pronounced as "Hao." As stated in *Mencius*, "Vision sufficient to see the tip of an autumn hair," precisely conveys this meaning. It indicates that Yin Qi descends from heaven, being light, fine, and floating, hence it is called "Hairy." The winter pulse being Stony occurs when all things hibernate in winter, representing the peak of Yin and the birth of Yang. The Kidney governs this season; the Kidney belongs to Water and governs storage. The pulse is deep and forceful, like a stone submerged in water, hence it is called "Stony." The principles of ascending, descending, floating, and sinking are infinitely variable; how could the rigid categories of Seven Exterior, Eight Interior, and Nine Channels fully encompass them! Furthermore, the pulse of harmonious Spleen and Stomach is neither large nor small, neither short nor long, difficult to describe explicitly, and can only be appreciated through intuitive contemplation. Those songs describing twenty-four pulse types are like looking at the sky through a tube (having a narrow perspective), alas!

Someone asked Shengshengzi (Sun Yikui's pseudonym): In texts treating Cold Damage (Shanghan), following the description of Guizhi Tang (Cinnamon Twig Decoction), it states: "If the pulse is floating and tight, with fever but no sweating, Guizhi Tang should not be administered; if given, the exterior will become more solidified, and sweating will become even more difficult." This seems to imply that Guizhi (Cinnamon Twig) is a medicine for consolidating the exterior. Why, then, is Guizhi used as a Deputy Minister (Chen) herb in Mahuang Tang (Ephedra Decoction)? Shengshengzi replied: Examining formulas to treat diseases relies entirely on the experiential understanding of medicinal properties and flavors (Qi Wei). *Yanyi* states that Cinnamon is greatly hot; its flavor is pungent and sweet, primarily warming the middle, benefiting Liver and Lung Qi, acting as a pioneer and guide for other herbs, gently harmonizing Ying and Wei (Nutritive and Defensive levels), and facilitating the action of various medicines without fear. Regarding the use of Cinnamon in Guizhi Tang: because the Defensive Qi has been attacked by pathogenic factors, leading to insecure Qi and thus sweating and aversion to wind, Cinnamon, with its pungent and sweet flavor, is a Yang agent. Yang agents act swiftly; upon ingestion, they disperse first, filling and reaching the hundred vessels and four limbs, penetrating everywhere. This represents the intention of dispersing. As for stopping sweating, this is the function of Shaoyao (Peony Root). Shaoyao has a sour flavor and is a Yin agent. Yin agents act slowly upon ingestion; thus, the formula first disperses and then collects/astringes. One opens, one closes; the pathogenic factor dissipates while the True Qi does not leak excessively, achieving a balanced state. It is not said that Cinnamon stops sweating. In Mahuang Tang, Cinnamon is used as a Deputy Minister also because its pungent and sweet dispersing nature is Yang. If it were believed to consolidate the exterior and stop sweating, what would be its purpose? It is likely because Cold damages the Nutritive level; Cinnamon assists Mahuang (Ephedra) to scatter Cold pathogens and gently harmonize Ying and Wei, so that pathogens cannot remain, and the disease resolves through sweating. The warning after Guizhi Tang regarding non-administration is due to the presence of Shaoyao in the formula. Since Cold has already damaged the Nutritive level, if there is fever and no sweating, using another sour-cold astringent agent would leave no exit for the pathogen, causing the exterior to become even more solidified. This is not to say that Pungent-Dispersing agents solidify the exterior. Wind is Yang Qi; Yang governs dispersion. When Wind damages the Defensive level, Qi scatters, resulting in sweating. Cold is Yin Qi; Yin governs consolidation. When Cold damages the Nutritive level, Qi contracts, resulting in no sweating. Therefore, treatment methods dictate: for no sweating, induce sweating to achieve sweating, utilizing Pungent-Dispersing properties; for existing sweating, stop sweating to achieve no sweating, utilizing Sour-Astringent properties. Both utilize Cinnamon because it can both disperse and gently harmonize Ying and Wei. Thus, I say: Examining formulas to treat diseases relies entirely on the experiential understanding of medicinal properties and flavors.