丹溪《格致余论》曰∶《生气通天论》病因四章，第一章“因于寒”之下“欲如运枢”三句，与上文意不相属，皆衍
文也，当以第二章“因于暑”之下，“体若燔炭，汗出而散”二句，移于因寒之下云云。尤在泾先生深通《经》义者也，
独于此论未甚研求，乃于《读书记》云∶因于寒、因于暑二节，丹溪重定章句为是。烈谓“因于寒”之下“欲如运枢”
句，不必谓之衍文，惟“起居如惊，神气乃浮”二句，与下文“体若燔炭，汗出而散”二句彼此舛错，仅以此四句互为
移掇，读作“因于寒，欲如运枢，体若燔炭，汗出而散。因子暑汗，烦则喘喝，静则多言，起居如惊，神气乃浮。”意即
贯串。盖谓因子寒者，如枢运动，寒气自散，如《内经》洗熨、按摩等法是也。若寒郁为热，有似燔炭，必须汗出而散，
如仲景麻黄汤之类是也。因于暑者，乃君火为病，故自汗、喘喝而多言，以及起居卒暴，神气浮越也。丹溪、在泾皆相
承而误。
本集第二卷，薛一瓢先生《日讲杂记》中有此一则，而语焉未详，书出之后，诸同学迭有来问此说者，爰为之详说
于左。
此本诸《素问遗篇·刺法论》，虽经张景岳类释于刚柔失守之条（甲、丙、戊、庚、壬，五年为阳，于气刚；乙、丁、
辛、已、癸，五年为阴，于气柔。应交而不布政者，谓之失守），而尚未甚晰，窃参鄙臆，详以明之。假如甲子年，上半
岁多风少暖，为上年司天之厥阴不退位，本年司天之少阴不迁正；若下半岁多凉，为在泉之阳明得位，甲子之在泉，阳
明已卯也（在泉之干，即以司天之干相合者推之，如甲与巳合，乙与庚合也。在泉之支，以司天之支各就四正、四偏、
四维中阴阳相配者推之，如子与卯为四正中之一阴一阳，寅与巳为四偏中之一阴一阳，辰与未为四维中之一阴一阳也，
余仿此）。以上年之司天，临本年之在泉，则上癸下巳，为不和。甲失其位，谓之木胜土虚（甲己化土），木胜必金复（指
下年乙庚化金之岁言），金既复，木必稍退，而子年司天之少阴至矣。木反助火克金，其复必微。而甲己之土皆失守，土
郁之久，后化为疫，早则丙寅，晚则丁卯，土疫至也（丙辛化水之年，久郁之士方得胜之而为病，再次年丁壬化木，木
又克土，亢则害而为病也。土疫即湿疫，今所谓湿温之类是也）。疫之微甚，详其年之司天在泉或盛或衰为定。又若上半
岁气暖，为少阴司天布政，而下半岁多温少凉，为上年在泉之少阳不退位，本年在泉之阳明不迁正，夫己卯之柔，不至
于下（本年在泉属阳明，己卯解见上），则甲子之刚，孤立于上，亦为土虚，后化为疠（凡司天失守化为疫，在泉失守化
为疠。疫、瘟疫也，疠、杀疠也）。土疫将至，恐伤肾脏，当先补肾俞，次泄土气以去其郁，戒夜行远行（经本论刺法，
故以俞言，用药者，亦仿其意可也）。其余详载《类经》，不必复赘，余年皆仿此。
疫疠每发于阳年，除天刑六年，其余二十四年是也（庚子、庚午君火刑金运，庚寅、庚申相火刑金运，戊辰、戊戌
寒水刑火运，此六年本非有余，故不发疫，余皆阳刚太过，故作疫也）。然此指阳运自胜而无邪伤者也，若刚柔迭失其位，
四时不节，谓之失之迭位，即生大疫（应司天而不司天，应在泉而不在泉，虽属阳年，亦为不及，不必郁至三年始发疫
疠也）。
丹溪在《格致余论》中说：《生气通天论》中关于病因的四章，第一章“因于寒”之下，“欲如运枢”这三句，与上文的意思不连贯，都是衍文（多余的文字），应当把第二章“因于暑”之下的“体若燔炭，汗出而散”这两句，移到“因于寒”的下面。尤在泾先生是深通《内经》经义的人，唯独对这篇论述没有深入研究，他在《读书记》中说：关于“因于寒”、“因于暑”两节，丹溪重新审定章节句读是正确的。我认为“因于寒”之下的“欲如运枢”一句，不必称为衍文，只是“起居如惊，神气乃浮”这两句，与下文“体若燔炭，汗出而散”这两句彼此错乱，只需将这四句互相交换位置，读作“因于寒，欲如运枢，体若燔炭，汗出而散。因子暑汗，烦则喘喝，静则多言，起居如惊，神气乃浮。”意思就能贯通了。大概意思是说，感受寒邪的，就像门轴转动一样，寒气自然消散，如同《内经》中提到的洗熨、按摩等方法。如果寒邪郁结化为热，症状像火烧一样猛烈，必须通过发汗来解散，如同张仲景麻黄汤之类的方剂。感受暑邪的，是因为君火致病，所以出现自汗、气喘呼叫和多言，以及起居突然受惊，导致神气浮越。丹溪和尤在泾都沿袭了这个错误。
本集第二卷中，薛一瓢先生的《日讲杂记》里有这一条记载，但语焉不详。书出版后，各位同学多次来询问这个说法，所以我在这里详细说明。
这种说法依据的是《素问遗篇·刺法论》，虽然张景岳在刚柔失守的条目下进行了分类解释（甲、丙、戊、庚、壬，五年为阳年，其气刚强；乙、丁、辛、己、癸，五年为阴年，其气柔和。应交替主政而不能布政的，叫做失守），但还不够清晰。我结合自己的见解，详细阐明它。假如是甲子年，上半年多风少暖，是因为上年司天之气厥阴风木不退位，本年司天之气少阴君火不迁正；如果下半年多凉，是因为在泉之气阳明燥金得位，甲子年的在泉之气是阳明燥金（推算在泉之天干，是以司天之天干相合来推导的，如甲与己合，乙与庚合等。推算在泉之地支，是以司天之地支分别对应四正、四偏、四维中阴阳相配的情况来推导的，如子与卯为四正中之一阴一阳，寅与巳为四偏中之一阴一阳，辰与未为四维中之一阴一阳等，其余仿照此例）。以上年的司天之气，临本年之在泉之气，则是上癸下己，属于不和。甲木失去了其正常位置，叫做木胜土虚（甲己化土），木气过胜必然引起金气来复（指下一年乙庚化金之年而言），金气既已来复，木气必然稍退，那么子年司天的少阴君火就到了。木反而助长火势以克制金气，其报复之力必然微弱。而甲己之土气都失守，土气郁结日久，后来化为疫病，早则在丙寅年，晚则在丁卯年，土疫就会到来（丙辛化水之年，久郁的土方才得以胜之而发病，再次年丁壬化木，木又克土，亢盛则为害而发病。土疫即湿疫，就是现在所说的湿温之类）。疫病的轻重，根据该年司天在泉之气的盛衰来确定。又如上半年气候温暖，是少阴君火司天布政，而下半年多温少凉，是上年在泉之气少阳相火不退位，本年在泉之气阳明燥金不迁正，那么己卯之柔气不能下达（本年在泉属阳明，己卯的解释见上文），则甲子之刚气孤立在上，也属于土虚，后来化为疠气（凡是司天失守化为疫，在泉失守化为疠。疫，即瘟疫；疠，即杀疠）。土疫将至，恐怕会损伤肾脏，应当先补肾俞穴，其次泄除土气以去除其郁结，禁止夜间行走和远行（经文原本论述针刺法则，所以用俞穴来说明，用药的人，也可以仿效这个意思）。其余详细内容记载在《类经》中，不必再赘述，其他年份都仿照这个例子。
疫疠多在阳年发生，除了天刑六年外，其余二十四年都是（庚子、庚午年君火刑金运，庚寅、庚申年相火刑金运，戊辰、戊戌年寒水刑火运，这六年本身并非有余，所以不发生疫病，其余都是阳刚太过，所以发生疫病）。然而这是指阳运自胜而没有外邪伤害的情况，如果是刚柔交替失守其位置，四季气候失常，叫做失之迭位，就会产生大疫（应司天而不司天，应在泉而不在泉，虽然属于阳年，但也属于不及，不必郁积至三年才发生疫疠）。
Danxi stated in *Gezhi Yulun* (Treatise on Cultivating Understanding): In the four chapters regarding etiology in *Shengqi Tongtian Lun* (Treatise on the Connection between Vital Qi and Heaven), the three sentences "yu ru yun shu" (desire like a rotating pivot) under the first chapter's "yin yu han" (due to cold) do not connect with the preceding context and are all interpolations (superfluous text). The two sentences "ti ruo fan tan, han chu er san" (body hot as burning charcoal, scattered by sweating) from the second chapter under "yin yu shu" (due to heat) should be moved below "yin yu han". Mr. You Zaijing, who deeply comprehends the meaning of the Classics, did not study this treatise thoroughly. In *Dushu Ji* (Records of Reading), he claimed that Danxi's reordering of the chapters for "due to cold" and "due to heat" was correct. I hold that the sentence "yu ru yun shu" under "yin yu han" need not be called an interpolation. Rather, the two sentences "qiju ru jing, shen qi nai fu" (daily life startled, spirit qi floats) and the following two sentences "ti ruo fan tan, han chu er san" are mutually misplaced. By simply swapping these four sentences, reading them as "yin yu han, yu ru yun shu, ti ruo fan tan, han chu er san. Yin yu shu han, fan ze chuan he, jing ze duo yan, qiju ru jing, shen qi nai fu," the meaning becomes coherent. This implies that for those affected by cold, like a pivot turning, the cold qi dissipates naturally, similar to methods such as washing, warming, and massage mentioned in *Neijing*. If cold stagnates and transforms into heat, resembling burning charcoal, it must be dispersed through sweating, similar to formulas like Mahuang Tang (Ephedra Decoction) by Zhang Zhongjing. For those affected by heat, it is a disease caused by Ministerial Fire, hence presenting with spontaneous sweating, panting and shouting, excessive talking, and sudden startling in daily life leading to floating spirit qi. Both Danxi and Zaijing inherited this error.
In Volume 2 of this collection, Mrue Xue Yupiao's *Rijiang Zajiji* contains this note but lacks detail. After the book was published, many students asked about this theory, so I elaborate here.
This originates from *Suwen Yipian · Cifalun* (Supplementary Chapters of Suwen · Treatise on Needling Methods). Although Zhang Jingyue classified explanations under the section on rigidity and softness losing their positions (Jia, Bing, Wu, Geng, Ren are five years of Yang, characterized by rigid qi; Yi, Ding, Xin, Ji, Gui are five years of Yin, characterized by soft qi. When they should exchange but fail to administer governance, it is called losing position), it remains unclear. Combining my own insights, I clarify it in detail. Suppose it is the Jiazi year: if the first half of the year has much wind and little warmth, it is because the previous year's Si Tian (Heavenly Governance) Qi, Jueyin Wind Wood, did not withdraw its position, and the current year's Si Tian Qi, Shaoyin Ministerial Fire, did not advance to its position. If the second half of the year is cool, it is because the Zai Quan (Earthly Governance) Qi, Yangming Dryness Metal, holds its position. The Zai Quan of Jiazi is Yangming Dryness Metal (The Heavenly Stem of Zai Quan is deduced by combining with the Heavenly Stem of Si Tian, e.g., Jia combines with Ji, Yi combines with Geng. The Earthly Branch of Zai Quan is deduced by matching Yin-Yang among Si Zheng, Si Pian, and Si Wei relative to Si Tian's branch, e.g., Zi and Mao are one Yin and one Yang in Si Zheng, Yin and Si are one Yin and one Yang in Si Pian, Chen and Wei are one Yin and one Yang in Si Wei, etc.). With the previous year's Si Tian overseeing the current year's Zai Quan, it results in Upper Gui and Lower Ji, indicating disharmony. Jia loses its position, termed Wood Excess and Earth Deficiency (Jia-Ji transform to Earth). Wood excess inevitably triggers Metal retaliation (referring to the next year Yi-Geng transforming to Metal). Once Metal retaliates, Wood recedes slightly, allowing Shaoyin Ministerial Fire of the Zi year's Si Tian to arrive. Wood assists Fire to overcome Metal, making the retaliation weak. Consequently, both Jia-Ji Earth loses its position. Long-standing Earth stagnation eventually transforms into epidemic diseases (Yi). Early in Bingyin year, late in Dingmao year, Earth Epidemic arrives (In Bing-Xin years transforming to Water, stagnant Earth finally overcomes and causes disease; in the subsequent Ding-Ren years transforming to Wood, Wood overcomes Earth, causing disease due to hyperactivity. Earth epidemic is damp epidemic, akin to modern Shiwarmth). The severity of the epidemic depends on the prosperity or decline of the year's Si Tian and Zai Quan. Furthermore, if the first half is warm, indicating Shaoyin Ministerial Fire governing, and the second half is warm with little coolness, indicating the previous year's Zai Quan ShaoYang Ministerial Fire did not withdraw and the current year's Zai Quan Yangming Dryness Metal did not advance, then the soft Qi of Jimao does not descend (Current Zai Quan belongs to Yangming, explanation of Jimao above). Thus, the rigid Qi of Jiazi stands isolated above, also constituting Earth deficiency, later transforming into Li Qi (Plague/Killing Pestilence). Whenever Si Tian loses position, it transforms into Yi (Epidemic); whenever Zai Quan loses position, it transforms into Li (Plague). Yi refers to plague; Li refers to killing pestilence. As Earth Epidemic approaches, fearing damage to the Kidney, one should first tonify Shenshu (Kidney Transport) acupoint, then drain Earth Qi to remove stagnation, and avoid night walking or long journeys (The classic discusses needling methods, hence mentioning transport points; physicians using herbs can follow this principle). Details are recorded in *Leijing*, no need to repeat. Other years follow this pattern.
Epidemics typically occur in Yang years, except for the six Tianxing (Heavenly Punishment) years, totaling twenty-four years (Gengzi, Gengwu: Ministerial Fire punishes Metal transport; Gengyin, Gengshen: Ministerial Fire punishes Metal transport; Wuchen, Wuxu: Cold Water punishes Fire transport. These six years are not excessive, hence no epidemic; others are overly rigid Yang, thus causing epidemics). However, this refers to Yang transport overcoming without external pathogen injury. If rigidity and softness alternate in losing their positions, and the four seasons are irregular, it is called "losing alternating positions," generating major epidemics (Si Tian fails to govern when it should, Zai Quan fails to govern when it should; even in Yang years, this constitutes insufficiency, not requiring three years of stagnation to trigger epidemics).