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The *Suwen: Pingren Qixiang Lun* states: "If the pulse in late summer is weak and soft yet exhibits a 'Stone' quality (Kidney pulse, associated with winter Qi), it indicates a disease of winter; if the Stone quality is pronounced, it indicates a current disease." (This passage is based on the *Maijing* and *Jiayi Jing*).

Examining the meaning of "Stone," it seems appropriate to interpret it as firm/hard. However, since the classic text juxtaposes "Stone" with "weak and soft," the imagery of the Stone pulse can be inferred from this. Generally speaking, "Firmness" belongs to long/continuous Qi, where the arrival and departure are mutually connected; "Stone" belongs to short/disconnected Qi, where both arrival and departure are severed: the two are indeed distinct. The *Suwen: Yuji Zhenzang Lun* states: "When the True Kidney pulse arrives, it beats and then cuts off, sounding like striking a stone with a finger—pi pi然." The term "cut off" (Jue) refers to the severance of arrival and departure. Another interpretation is that it feels like pulling a rope taut ("Duo" is an ancient form of "Tuo," seen in the *Shuowen Jiezi*; Duo Suo means severed). Thus, the Stone pulse derives its meaning from "severance/disconnection," not from "firmness," which is why it can be juxtaposed with "weak and soft." However, the Stone pulse that sounds pi pi lacks Stomach Qi, whereas the weak-and-soft pulse containing Stone qualities possesses Stomach Qi. Therefore, the former is termed a death pulse, while the latter is termed a disease pulse! The reason why the Stone pulse is taboo in late summer is that the Spleen's normal pulse separates from the Stone pulse. Like a chicken stepping on the ground, this separation is subtle and not easily perceived; the Stone pulse, however, represents a conspicuous separation. The term "separation" implies disconnection. To go from a barely perceptible separation to a clearly visible one indicates that Spleen Qi is weak and Kidney Qi is strong, hence disease arises.

The mechanism by which Yupingfeng San (Jade Windscreen Powder) stops sweating is not analogous to how a plasterer treats a wall. It posits that sweating caused by wind pathogen often constantly depletes Wei Qi (Defensive Qi) and causes it to linger. When Wei Qi fails to consolidate, and wind lingers impurely, the impure wind exploits the lack of consolidation, making sweating easy. Therefore, Fangfeng (Saposhnikoviae Radix) must be used to disperse wind from the exterior, Baizhu (Atractylodis Macrocephalae Rhizoma) to guard the middle, and Huangqi (Astragali Radix) to support/supportive tonification from within. The character "Qi" in Huangqi implies "to reach/push forward" (as in *Shijing: Huangyi*: "Shangdi qi zhi," where Qi means to reach). By pushing/reaching Wei Qi so that wind cannot remain, Wei Qi naturally consolidates and sweating naturally stops. This is the rationale of the formula. People see that it stops sweating and assume Huangqi merely consolidates the exterior. Why not observe the two phrases under the prescription: "treating wind pathogen lingering for a long time without dispersing, and spontaneous sweating that does not cease"? The *Shennong Bencao Jing* states: "Huangqi treats severe wind." This formula is based on this principle. Thus, its rationale differs from but also shares similarities with formulas using Huangqi for blood bi, yellow sweat, and jaundice in the *Jingui Yaolue*, because those conditions are also caused by Wei deficiency combined with wind. The combination of Fangfeng and Baizhu is taken from the Guizhi Shaoyao Zhimu Tang (Cinnamon Twig, Peony, and Anemarrhena Decoction) in the *Jingui Yaolue*, again because those conditions were caused by wind-induced sweating. Inferring one condition from another, this is clear. One may only use this formula if the patient's symptoms match those described under the prescription. If sweating is not due to wind, or if there is slight wind but the constitution is exterior deficiency with interior excess, it should not be taken. Taking it would cause Wei Qi to be pushed outward and become more deficient, making exterior deficiency worse and interior excess more apparent, leading to disharmony of all Qi. Even if there was no sweating initially, it could induce sweating. How could one seek to avoid sweating by using this to stop it? Furthermore, the name "Pingfeng" (Windscreen) carries the meaning of shielding and blocking. If interpreted solely as a physical barrier, one focuses on the name while missing the substance. Generally, famous formulas of ancient and modern times, if they capture even one aspect of Zhang Zhongjing's thought, cannot be understood merely by looking at the words. Readers should infer the intent through their own understanding.