Library

*This Matter is Hard to Know* states: "Winter follows the command of Autumn; it should be cold but is warm, indicating excessive Fire and deficient Water," and so on. Deducing this as the origin of pestilential diseases is indeed reasonable. However, it further states: "Fire and Earth combine their virtues, with damp-heat assisting each other, thus becoming warm disease." This implies that warm diseases must originate from damp-heat, in which case the category of "damp-heat" could be abolished. One must understand that damp-heat is the righteous qi (normal climate) of summer, whereas pestilence is the miscellaneous qi of heaven and earth; the two are vastly different. It may be said that pestilential diseases can involve damp-heat, but I have never heard of damp-heat itself causing warm disease. It also states: "Only those who suffer from sexual excess and hard labor contract this." Does this mean that those who abstain from sex and live in comfort will certainly not get pestilence? Is there such logic? I often see that in years when pestilence prevails, people who practice moderation and live comfortably often contract it without apparent cause. How does one account for this? It further states: "Those with excessive desires and hard labor have their Kidney water exhausted internally and their Yang qi leaking externally. Since the source of generation and transformation is cut off, what remains in the body is only heat," and so on. It is acceptable to say that this is one type among pestilential diseases, but to claim that all pestilential diseases stem from this is absolutely illogical. Regarding the character "Shu" (summer heat), *Zihui* defines it as the hot air of summer. Therefore, anyone affected by this qi cannot logically be classified under a Yin syndrome. The term "Yin Shu" (Yin Summer Heat) arises only because people fear the summer heat and seek coolness, thereby contracting external Cold pathogenic factors. This is essentially a common cold. By ignoring the current contraction of Cold and sticking rigidly to the prior exposure to Summer Heat, they name it "Yin Shu." This is akin to saying "Yin Heat." Is there any logic in this? If one recognizes that the phrase "Yin Heat" is nonsensical, it becomes clear that "Shu" cannot be described as "Yin."

Wu Youke, in his *Treatise on Pestilence*, refutes the theory of Winter Warmth, stating: "Summer coolness and winter warmth result in obtaining the harmonious qi of Spring and Autumn. Could it be that this harmony causes illness? The order of the four seasons dictates that it should be cold when it ought to be cold, and warm when it ought to be warm. Thus, humans receiving the righteous qi of heaven and earth do not become ill. If summer should be hot but is instead cool, or winter should be cold but is instead warm, illness inevitably results. However, if summer is excessively cool, the resulting illness appears immediately. But if winter weather is excessively mild, it often causes no harm at the time, only to erupt into widespread pestilence during the following spring and summer. This is something I have experienced and verified repeatedly; it is truly not a baseless speculation. Indeed, if summer should be hot but is cool, humans contract Cold pathogenic factors, causing the couli (pores) to close and preventing dispersion; the resulting illness is hardly surprising. However, the fact that non-seasonal warmth in winter does not cause immediate illness, but only manifests in the following spring and summer, is truly inexplicable. People often say: 'Injury by Cold in winter transforms into Warm or Shu diseases in spring and summer.' I say: 'Excessive warmth in winter leads to frequent pestilential diseases in spring and summer.' Wu Youke claims that winter warmth and summer coolness are insufficient to cause disease, an opinion I reject. Warmth belongs to Spring, and coolness belongs to Autumn. Warmth and coolness constitute the righteous qi of Spring and Autumn, and are appropriately termed 'Harmony' (He). If these appear during the commands of Winter and Summer (i.e., summer coolness and winter warmth), this constitutes 'qi present out of season,' and thus cannot be called 'Harmony.' Disharmony is abnormal, pernicious qi. This is why summer coolness and winter warmth frequently cause disease. How can one argue that warmth and coolness do not necessarily cause illness?"