温也，疫也，温疫也。三病之称，第称温疫者为定名，而称温、称疫者为虚位。温者，
蕴也
。儒书谓夫子温良，言容之蕴；诗教温柔，言辞之蕴；良玉温润，言彩之蕴。医书谓春气温
和，言阳之蕴；则病之称温，必以其邪之蕴也。蕴寒曰温，蕴热亦曰温。《伤寒例》冬伤于
寒，至春变为温病，是蕴寒者；冬有非节之暖，名曰冬温，及《巢源》冬感非时之暖，至春
亦为温病，是蕴热者。所蕴不同，而其为温则同也。言乎其治，则一于寒，何也？其初则异
，其终则同也。然而论治可通者，临文必不可通，着书之指，固与临症别也。疫者役也，传
染之时，病状相若，如役使也。役于寒曰疫，役于热亦曰疫。《伤寒例》之疫可谓是疫于寒
者，《巢源》、《千金》以下诸书之疫，半是疫于热者，所役不同，而其为疫则同也。然此
所谓寒若热者，非正邪之寒热也，必惑夫反时者始相役也。故温有正邪之温，而疫无不由于
贼邪。古谓贼病为时气，一曰时行，故后世称疫为时疫。然时气乃贼邪之混称，不暇详其传
染与否也。其传染者，若仅目之为时气，则无以示别也。且传染之气，恶于不传染者，不得
不别也。疫气恶，故疫亦曰疠疫，疠之为言恶也，此疫之别于时气也。或曰∶如此则役于热
者，不几与温相混乎？曰∶否。冬温亦以传染者为疫，其未经传染，或止就一人言之也，直
称温，不得称疫。温者先乎病以言之，疫者后乎病以言之，以其各有寒若热，故曰虚位。若
合温、疫两字以名之之病，则惟《伤寒例》阳脉濡弱，阴脉弦紧，遇温气变为温疫者，可以
当之。以其先有温邪，又传染时气中之寒之役使者，例不得另立一名，故叠此两字以呼之，
所谓定名也。至于温热云者，其指多本《内经》先夏至为温，后夏至为热之文，而括其轻重
之谓，倘知温之为蕴，则温、热两病之仅皆属温可决已。周扬俊以《温热暑疫》名其书，而
王孟英着《温热经纬》，复杂取《伤寒论》文，皆由不能识别，则不敢正称，而姑以含糊囫
囵，可以附古可以欺今之温、热两字，为藏身之固，使人不便显言其非耳！近世医说之不足
恃类此。
"Wen" (Warmth), "Yi" (Plague/Epidemic), and "Wen Yi" (Warm Plague). Among these three terms, only "Wen Yi" is a fixed name, whereas "Wen" and "Yi" used separately represent virtual positions (conceptual categories).
"Wen" means "accumulation" or "entrapment". Confucian texts describe Confucius as "wen liang" (gentle and good), referring to the accumulation of demeanor; the teachings of the *Classic of Poetry* emphasize "wen rou" (gentle and soft), referring to the accumulation of speech; fine jade is described as "wen run" (warm and moist), referring to the accumulation of luster. Medical texts state that spring climate is "wen he" (mild and harmonious), referring to the accumulation of Yang Qi. Therefore, diseases are called "Wen" because of the entrapment of pathogenic factors. Entrapped Cold Evil is called "Wen", and entrapped Heat Evil is also called "Wen". The *Shanghan Li* (Treatise on Cold Damage Examples) states that injury to Cold in winter transforms into Wen Bing (Warm Disease) in spring; this belongs to the case of entrapped Cold. Winter warmth occurring out of season is named "Dong Wen" (Winter Warmth); similarly, according to the *Zhubing Yuanhou Lun* (Source Book of All Diseases), contracting non-seasonal warmth in winter leads to Wen Bing in spring; this belongs to the case of entrapped Heat. Although the nature of what is trapped differs, both are termed "Wen". Regarding treatment, why is it uniformly cold-natured? Because the initial stages differ, but the final outcomes converge. However, theories that may be universally applied cannot be indiscriminately applied in clinical practice; the purpose of writing medical books is inherently distinct from clinical diagnosis and treatment.
"Yi" means "service" or "driving force" (like corvée labor), characterized by contagion, simultaneous onset, and similar symptoms, akin to being driven. Being driven by Cold Evil is called "Yi"; being driven by Heat Evil is also called "Yi". The "Yi" mentioned in the *Shanghan Li* can be considered as being driven by Cold Evil. In books following the *Zhubing Yuanhou Lun* and *Qianjin Fang*, half of the cases of "Yi" are driven by Heat Evil. Although the driving pathogens differ, all are termed "Yi". However, the Cold or Heat referred to here is not the balance of Zheng Qi (Upright Qi), but rather results from being misled by abnormal seasonal climates. Thus, "Wen" has distinctions between Zheng Qi and Xie Qi (Pathogenic Factors), whereas "Yi" invariably stems from Zei Xie (Thief Pathogens/Highly Virulent Pathogens). Ancients referred to such diseases as "Shi Qi" (Seasonal Qi) or "Shi Xing" (Seasonal Epidemic), hence later generations called "Yi" "Shi Yi" (Seasonal Plague). However, "Shi Qi" is a general term for Zei Xie, without detailing whether it is contagious. If contagious diseases were merely labeled "Shi Qi", there would be no distinction made. Furthermore, contagious Qi is more malignant than non-contagious Qi, necessitating differentiation. Since "Yi Qi" is malignant, "Yi" is also called "Li Yi" (Malignant Plague); "Li" implies malignancy. This distinguishes "Yi" from "Shi Qi".
One might ask: Does being driven by Heat Evil not confuse with "Wen"? The answer is no. "Dong Wen" (Winter Warmth) is called "Yi" if it is contagious; if it has not been transmitted, or refers to an isolated individual, it is directly called "Wen" and not "Yi". "Wen" is discussed based on the pre-disease state, while "Yi" is discussed based on post-disease transmission. Because they possess respective Cold or Heat attributes, they are termed virtual positions. The disease named by combining "Wen" and "Yi" corresponds only to the case in the *Shanghan Li*: where Yang pulse is Ru Ruo (Soft and Weak), Yin pulse is Xuan Jin (String-taut and Tight), transforming into "Wen Yi" upon encountering Warm Qi. This is because there was prior Wen Xie (Warm Pathogen), compounded by the driving force of Cold within the Seasonal Qi. According to the systematic framework, a new name cannot be established, so these two characters are stacked to call it, which is the so-called "Fixed Name".
As for "Wen Re" (Warm-Heat), its reference mostly stems from the *Neijing* (Inner Canon) text stating "before Summer Solstice is Wen, after Summer Solstice is Re", used to gauge severity. If one understands that "Wen" signifies accumulation, it is certain that both "Wen" and "Re" diseases fall under the category of "Wen". Zhou Yangjun titled his book *Wen Re Shu Yi* (Warmth, Heat, Summerheat, and Plague), and Wang Mengying wrote *Wen Re Jing Wei* (The Classic and Coordinate of Warmth and Heat), incorporating texts from the *Shanghan Lun* (Treatise on Cold Damage). This is due to their inability to clearly distinguish concepts, leading them to dare not use precise terminology. Instead, they vaguely employ the ambiguous terms "Wen" and "Re"—which can flatter ancients and deceive moderns—as a shield, preventing others from explicitly pointing out their errors. Such unreliability characterizes recent medical theories.