运气之说，有太过不及，而胜复由以生正。太过者，其气胜，胜而复制，则伤害甚矣。
者，其气衰，衰而复克，则败乱极矣。此胜复循环之道，出乎天地之自然，而亦不得不然也
。故在天有五星胜气之应，在地有万物盛衰之应，在人则有脏腑疾病之应。如木强胜土，则
岁星明而镇星暗，土母受侮，子必复之，故金行伐木以救困土，则太白增光，岁星反晦也。
凡气之现于上者，则灾应乎下，宿属受伤，逆犯尤甚。正运互为胜复，其气皆然，至其为病
，如木胜肝强，必伤脾土，肝胜不已，燥必复之，而肝亦病矣。燥胜不已，火必复之，而肺
亦病矣。此五脏互为盛衰，其气亦皆然也。夫天运之有太过不及者，即如人身之有虚实也。
惟其有虚而复，强者胜之。有胜而复，承者复之。无衰，则无胜矣。无胜则无复矣。其气和
平，焉得有病？恃强肆暴元气先尽，焉得毋虚。故曰∶有胜则复，无胜则否，胜微则复微，
胜甚则复甚。可见胜复之微甚，由变化之盛衰，本无其常也。六元正纪论所载天时地化人事
等议，至详至备，盖以明其理之常者如此也。即如周易之六十四卦，三百八十四爻，乃阐明
易道之微妙，教人因易以求理，因象以致变。故孔子曰∶书不尽言，言不尽意。此其大义，
正与本经相同。夫天道元微，本不易测，及其至也，虽圣人亦有不知焉。故凡读易者，当知
易道有此变，不当曰变止于此也。读运气书者，当知天道有是理，不当曰理止于是也。然变
化虽难必，而易尽其机也。天道虽难测，而运气尽其妙矣。自余有知以来，常试以五大之义
，逐气推测，则彼此盈虚，十应八九，即有少不相符者。正如井蛙之见，而见有未至耳，岂
天道果不足凭耶？今有昧者，初不知常变之道，盛衰之理，孰者为方，孰者为圆，孰者为相
胜反胜主容承制之位。每执凿经文以害经意，徒欲以有限之年晨，概无穷之天道，隐微幽显
，诚非易见管测求全，陋亦甚矣。此外复有不明气化，如马宗素之流者，假仲景之名，而为
《伤寒钤法》，用气运之更迁，拟主病之方治，拘滞不通，诚然谬矣。然又有一等偏执己见
，不信运气者，每谓运气之学，何益于医？且云∶疾病相加，岂可根据运气以施治乎？非切要也
？余喻之曰∶若所云者，是真运气之不求，而运气可易言哉，观岁运之流行，即安危之关系
。或疫气遍行一方，皆病风温，或清寒伤脏，一时皆犯泻痢。以众人而患同病，谓非运气之
所使然欤。
关于五运六气的学说，存在太过与不及两种情况，而胜气与复气由此产生。所谓“太过”，是指该年的气化偏盛，偏盛之后必然产生克制它的复气，这样造成的伤害就非常严重了。所谓“不及”，是指该年的气化衰弱，衰弱之后被其所不胜之气克制，随后又引发复气，这样导致的败坏和混乱就达到了极点。这种胜气与复气循环往复的规律，出自天地自然的法则，也是不得不如此的必然结果。
因此，在天象上有五星（岁星、荧惑、镇星、太白、辰星）对应胜气的显现；在地面上有万物生长收藏盛衰的应验；在人体上则有脏腑疾病的反应。例如，木气过强而克制土气，那么代表木的岁星就会明亮，而代表土的镇星就会昏暗，土受到侮慢，其子金气必定会进行报复，所以金气会伐木以救助受困的土气，此时代表金的太白星就会增光，而岁星反而变得晦暗。凡是出现在天上的气化现象，都会在地下产生灾异响应，如果宿属（对应星宿或方位）受伤，逆乱侵犯的情况尤为严重。主运之间互为胜复，其气化规律都是如此。至于它们导致疾病时，如木气胜则肝气强盛，必定会损伤脾土；如果肝气胜而不止，燥金之气必定会来复，从而导致肝病；如果燥金之气胜而不止，火气必定会来复，从而导致肺病。这五脏之间互为盛衰，其气化规律也都是这样的。
上天运行的太过与不及，就像人身体的虚与实一样。正因为有虚，所以会有复气来补充；正因为有强盛，所以会有克制它的气出现。有胜气就会有复气，有承袭之气就会有复气。如果没有衰弱，就不会有胜气；没有胜气，也就不会有复气。如果气化平和，怎么会有疾病呢？倚仗强势肆意暴戾，元气先耗尽，怎么会不虚损呢？所以说：有胜气就有复气，没有胜气就没有复气；胜气轻微则复气轻微，胜气严重则复气严重。由此可见，胜复的轻微或严重，是由变化的盛衰决定的，本来就没有固定的常态。《素问·六元正纪大论》中记载的天时、地化、人事等议论，非常详尽完备，大概就是为了阐明这种常理是这样的。
就像《周易》中的六十四卦、三百八十四爻，是为了阐明易道的微妙，教导人们通过易理来探求道理，通过卦象来推知变化。所以孔子说：“书不尽言，言不尽意。”这里的宏大义理，与本经（指《黄帝内经》运气七篇）是相同的。天道原本幽微，本就不容易推测，即使到了极致，即使是圣人也有不知道的地方。所以凡是读《周易》的人，应当知道易道中有这种变化，不应当说变化只限于此。凡是读运气书籍的人，应当知道天道中有这些道理，不应当说道理只限于此。然而变化虽然难以完全预测，但可以通过观察掌握其机理。天道虽然难以测度，但运气学说已经穷尽了其中的奥妙。
自从我有所知识以来，常常尝试用五运六气的大义，逐气进行推测，彼此之间的盈虚变化，十次能应验八九次，即使有少许不相符的地方，也正如井底之蛙所见有限，只是见识没有到达那里罢了，难道天道真的不可凭信吗？现在有一些愚昧之人，起初根本不知道常与变的道理、盛与衰的规律，分不清谁是方、谁是圆、谁处于相胜、反胜、主容、承制的位置。他们往往执着于穿凿经文而损害经文的真意，只想用有限的年份，去概括无穷的天道，对于隐微幽深显浅的道理，确实不是容易通过管窥蠡测就能求全的，这也太浅陋了。
此外，还有不明白气化规律的人，像马宗素这类人，假借张仲景的名义，编写《伤寒钤法》，用气运的更替变迁，来拟制主治疾病的方药，拘泥停滞不通达，确实是错误的。但是又有一类人偏执己见，不相信运气学说，常常说：运气之学，对医学有什么益处？并且说：疾病叠加发生，怎么能根据运气来施治呢？这不是切要的吗？我开导他们说：如果像你所说的那样，那是真正不去探究运气，运气又岂是轻易能谈论明白的呢？观察岁运的流行，就是安危的关键关系。或者疫气遍行一方，大家都患风温病；或者清寒损伤内脏，一时都犯泻痢。让众人患上同样的疾病，难道不是运气使然吗？
The theory of Five Movements and Six Qi involves the concepts of Excess (Tai Guo) and Deficiency (Bu Ji), from which Winning (Sheng) and Repaying (Fu) qi arise. "Excess" refers to when the qi is dominant; after dominance, a repaying qi arises, causing severe damage. "Deficiency" refers to when the qi is weak; after weakness, it is overcome by its conquering element, followed by a repaying qi, leading to extreme chaos and ruin. This cycle of winning and repaying follows the natural laws of Heaven and Earth and is inevitable.
Therefore, in the heavens, there are responses corresponding to winning qi manifested by the five planets (Jupiter, Mars, Saturn, Venus, Mercury); on earth, there are responses in the flourishing and declining states of all things; and in humans, there are responses in the form of zang-fu diseases. For instance, if Wood qi is strong and overacts on Earth, Jupiter (Sui Xing) will shine brightly while Saturn (Zhen Xing) appears dim. Earth, being humiliated, has its child Metal act to repay this injury; thus, Metal attacks Wood to rescue the distressed Earth, causing Venus (Tai Bai) to brighten while Jupiter becomes dim. Any qi manifestation in the upper heaven corresponds to disasters below; if the associated constellation or direction is injured, the adverse invasion is particularly severe. The main movements interact through winning and repaying, and their qi patterns are all like this. Regarding disease manifestation: if Wood wins, Liver qi becomes strong, inevitably injuring Spleen Earth. If Liver winning persists, Dryness (Metal) will repay, causing Liver disease. If Dryness winning persists, Fire will repay, causing Lung disease. The five zang organs mutually influence each other's flourishing and declining, and their qi dynamics follow similar principles.
The excess and deficiency in heavenly movement are analogous to deficiency and excess in the human body. Because there is deficiency, there is repaying qi to supplement; because there is strength, there is conquering qi to restrain. Where there is winning, there is repaying; where there is succession, there is repaying. Without deficiency, there is no winning; without winning, there is no repaying. If the qi is balanced and peaceful, how can disease arise? Relying on strength to act tyrannically exhausts the Yuan Qi first, leading inevitably to deficiency. Thus it is said: "Where there is winning, there is repaying; where there is no winning, there is no repaying. A slight winning results in slight repaying; a severe winning results in severe repaying." It is evident that the degree of winning and repaying depends on the flourishing and declining of changes, having no fixed constant. The discussions on heavenly timing, earthly transformation, and human affairs recorded in the *Treatise on the Six Sources and Correct Chronicle* (*Liu Yuan Zheng Ji Lun*) are extremely detailed and comprehensive, presumably to clarify that such constancy exists.
Just as the sixty-four hexagrams and three hundred and eighty-four lines of the *I Ching* elucidate the subtleties of the Way of Change, teaching people to seek principles through the I and derive transformations through images, Confucius stated: "Writing cannot fully express speech, and speech cannot fully express intent." The great significance here aligns with this classic text. The Way of Heaven is originally subtle and not easily fathomed; even at its utmost, sages may not know everything. Therefore, those who study the *I Ching* should know that the Way of Change contains such variations and should not claim that variation ends here. Those who study theories of Movement and Qi should know that the Way of Heaven contains these principles and should not claim that principle ends here. Although change is difficult to predict completely, one can exhaust its mechanisms. Although the Way of Heaven is hard to measure, the theory of Movement and Qi exhausts its wonders.
Since acquiring knowledge, I have often attempted to speculate on each qi using the general principles of the Five Movements. The mutual waxing and waning corresponded correctly eight or nine times out of ten. Even when there were slight discrepancies, it was merely like the limited view of a frog in a well, where perception had not yet reached that point. How could the Way of Heaven truly be unreliable? Now, some ignorant individuals do not initially understand the principles of constancy and change, or flourishing and decline. They fail to distinguish the positions of Fang (Square/Directional), Yuan (Round/Cyclical), Xiang Sheng (Mutual Conquest), Fan Sheng (Reverse Conquest), Zhu Rong (Main Containment), and Cheng Zhi (Succession and Restraint). They stubbornly adhere to forced interpretations of the classics, harming the true meaning, and attempt to use finite years to generalize infinite heavenly ways. Grasping the hidden, subtle, dark, and manifest aspects is indeed not easy through tube-viewing or gourd-measuring; this is exceedingly shallow.
Furthermore, there are those who do not understand qi transformation, such as Ma Zongsu, who falsely used Zhang Zhongjing's name to compile the *Shanghan Lianfa* (Methods for Cold Damage). Using the migration of qi and movement to prescribe formulas for primary diseases is rigid, inflexible, and indeed erroneous. However, there is another group who are biased and固执 (stubborn), disbelieving in the theory of Movement and Qi. They often ask: "What benefit does the study of Movement and Qi have for medicine?" and say, "Diseases occur simultaneously; how can treatment be based on Movement and Qi? Is this not irrelevant?" I advised them: "If you speak thus, you truly do not seek to understand Movement and Qi; how then can it be discussed lightly? Observing the circulation of annual movements relates directly to safety and danger. Or epidemic qi spreads across a region, and everyone suffers from Wind-Warmth; or cold damages the viscera, and everyone suffers from diarrhea and dysentery. That many people suffer the same disease—is this not caused by Movement and Qi?"