问曰、五行各有正气。天地所合。干支所同。而阴阳之用。各有变迁。又参错不同何也。曰、此正所谓三合之治也。
三合而治。必将合气。必为主用。或从本气。或从标气。或因乎其盛。或由乎其化。虽有不同。要皆取用以崇体。而不
以体劳物也。如五运以土为首而加甲。自甲为土以下。皆不用干矣。而甲丙戊庚壬值年。仍为气太过。乙丁巳辛癸值年。
仍为气不及。其干虽变。而阴阳不变。则原非不用干也。司天亦变支矣。而火当午。土当丑未。金当酉。与岁为会。则
为当其位而合其气。是皆不变本位。亦不废本支也。大约阴阳之用。合两而成。以三为用。故阴阳之行。虽一体。而动
变则各由其道。各由其道者。所以妙阴阳之用也。一切三合变气皆如此。知其用则不疑其变矣。
问曰、司天运气合用。而有天符岁会。乃有小五运。复参于司天在泉。运气之间。则又何也。曰五行三合之治。无
往而不用。亦无往而不三合也。如辰戌太阳司天矣。而辰戌备历甲丙戊庚壬之五位。则五运亦尽历寒水之一位矣。寒水
唯一。而有五变。五变之中。所营运以周一岁者。亦各有五运。犹司天之间立纪步也。既以大五运与司天为乘临。则亦
有小五运与间步为乘临。此亦阴阳自然之道也。岁气必以木为主。故以太少角为初。以太少羽为终。五运之生序不可紊
也。然其用微。不及间步之剧。故经不着病。要使人知之尔。
问曰、五行五用。而各为首。六气首风木。司天首火。五运首土。五行本生首水。其成首金。循环而能为首者。岂
有义乎。曰、此阴阳造化之妙用。不可思议者也。由其初而言生物之始。始于天一。天一水也。水得暖而升。故火继之。
火水鼓荡而形成。故木继之。木长而坚。故金继之。四者非土不成。故成必以土也。洪范之序如此。盖生物之原也。若
四时六气。必以岁德为首。岁德在木。故木起厥阴。而临官于寅。所以达生气通人事也。自木而火。而土而金。以止于
水。四时之序。生长化收藏之事。五运之首土者。天之气自中而运。而戊己居中以生养万物。故即此中宫推之。以四正
环而拱之。以行其生生之用。此在天之事也。若司天以火为首者。少阴君火。有帝之尊。于以出治。孰不归仰焉。然唯
斗杓初指。帝乃临之。帝出乎震。故以火为首。而以厥阴为终。盖三阴为朋。今少阴居中。而厥阴在前。则必俟历三阳。
而厥阴为后矣。厥阴位亥。亦终之义也。由其成功而言。金木者生成之终始也。显万类之成。而列万形之质。此不唯其
始。而唯其终。故必见其坚成。而后水木火土四形备具也。此成物之序。以其致用而言之也。
问曰、四时阴阳顺逆之行。有左右之辨何也。曰、阳自下而上。故左旋而为春夏。阴自上而下。故右旋而为秋冬。
是以春为生气而西行。变其收气而为暄。夏为长气而北行。变其脏气而为热。秋为收气而东行。敛其生气而为凉。冬为
藏气而南行。敛其长气而为寒。西北行为顺。东南行为逆。春夏日躔北陆而长。秋冬日躔南陆而短。亦阴阳顺逆之序也。
问曰、经谓阴中有阳。阳中有阴。何也。曰、阴阳本合一者也。自太极动而生阳。静而生阴。立之以两。而相为对
待。此各一之一。人所易知也。以动静为鼓舞。以阴阳为妙用。无形而致有形。同体而立异体。阴阳合作。而鼓化机。
此合一之一。人所难知也。是故本其太始而言。阴阳之原。由于一机。静极而阳生。动极而阴生。阴阳互相生也。本其
成位而言。阴阳之根。互藏其宅。火胎子中。水胎午中。阴阳互相宅也。人能悟阴阳之本一。乃能知阴阳之能两也。
问：五行各自拥有其正气，这是天地相合、干支共同体现的。然而阴阳的作用，却各有变迁，又参差错落、各不相同，这是为什么呢？
答：这正是所谓的“三合”治理之道。所谓“三合而治”，必然要融合气机，并且必有主导作用。有时遵循本气，有时遵循标气；有时因为气盛而顺从，有时因为气化而改变。虽然表现形式不同，但归根结底都是为了取用气机以尊崇本体，而不是让本体劳损万物。例如五运中以土为首并加上天干甲，从甲为土开始以下，都不再使用其他天干了。但是甲、丙、戊、庚、壬值年时，仍然代表气太过；乙、丁、己、辛、癸值年时，仍然代表气不及。虽然天干有所变化，但阴阳的本质没有改变，这原本就不是不用天干。司天之气也改变了地支，但火对应午，土对应丑未，金对应酉，与岁支相会，这就是当位而合其气。这些都是不改变本位，也不废弃本支的道理。大抵来说，阴阳的作用，合两而成，以三为用。所以阴阳的运行，虽然是一个整体，但动变则各自遵循其道。各自遵循其道，就是为了精妙地运用阴阳。一切三合变气都是如此，知道了它的作用，就不会对它的变化产生疑惑了。
问：司天运气合用，有天符、岁会，还有小五运，又参杂于司天在泉之间，这又是为什么呢？
答：五行三合的治理，无处不用，也无处不是三合。例如辰戌年是太阳寒水司天，而辰戌备历甲、丙、戊、庚、壬这五位，那么五运也就尽历寒水这一位了。寒水只有一位，却有五种变化。在这五种变化中，所营运以周流一岁的，也各有五运，就像司天之间的纪步一样。既然有大五运与司天相乘临，也有小五运与间步相乘临，这也是阴阳自然的道理。岁气必须以木为主，所以以太少角音为初，以太少羽音为终。五运的生序是不可紊乱的。然而它们的作用细微，不如间步剧烈，所以经文不着重记载相关的病症，只是让人知道罢了。
问：五行有五用，且各为首领。六气之首是风木，司天之首是火，五运之首是土，五行本生之首是水，其成之首是金。循环往复都能为首，难道有什么义理吗？
答：这是阴阳造化的精妙作用，不可思议。从其初始而言，生物的开始，始于天一。天一是水。水得暖而上升，所以火继之。水火鼓荡而形成，所以木继之。木生长而坚硬，所以金继之。这四者没有土就不能成就，所以成就必须以土为主。《洪范》的次序就是这样，这是生物的本源。至于四时六气，必须以岁德为首。岁德在木，所以木起于厥阴，而在寅月临官，以此来通达生气，通晓人事。从木到火，到土，到金，最终止于水，这是四时的次序，生长化收藏的事情。五运之首为土，是因为天的气从中而运，戊己居中而生养万物，所以从这个中宫推演，以四方正位环绕拱卫它，来施行生生不息的作用，这是在天的事情。至于司天以火为首，是因为少阴君火有帝王的尊贵，以此出治，谁不归仰呢？然而只有斗杓初指东方，帝王才降临。帝出乎震（东方），所以以火为首，而以厥阴为终。大概三阴为朋党，现在少阴居中，而厥阴在前，那么必须经历三阳之后，厥阴才排在最后。厥阴位于亥位，也是终结的意思。从其成功而言，金和木是生成之始终。显现万类的成就，排列万形的体质，这不仅看重开始，更看重终结，所以必须见到其坚成，然后水、木、火、土四种形体才具备齐全。这是成物的次序，是从其致用的角度说的。
问：四时阴阳顺逆的运行，有左右的区别，为什么呢？
答：阳自下而上行，所以左旋而为春夏；阴自上而下行，所以右旋而为秋冬。因此春为生气而向西行，将其收气变为温暖；夏为长气而向北行，将其脏气变为炎热；秋为收气而向东行，收敛其生气变为凉爽；冬为藏气而向南行，收敛其长气变为寒冷。向西北行是顺，向东南行是逆。春夏日躔北陆而昼长，秋冬日躔南陆而昼短，这也是阴阳顺逆的次序。
问：经文说阴中有阳，阳中有阴，为什么呢？
答：阴阳原本是合一的。自从太极动而生阳，静而生阴，确立了两仪，相互对待。这是各为一的一，是人容易知道的。以动静为鼓舞，以阴阳为妙用，无形而转化为有形，同体而立异体，阴阳合作而鼓动化机，这是合一的一，是人难以知道的。所以追溯其太始而言，阴阳的本原，由于一个机枢。静极而生阳，动极而生阴，阴阳互相滋生。追溯其成位而言，阴阳的根本，互藏在对方的宅舍中。火胎藏于子中，水胎藏于午中，阴阳互藏宅舍。人能领悟阴阳之本是一，才能知道阴阳能分为二。
Q: Each of the Five Phases (Wu Xing) possesses its own proper Qi. This is what Heaven and Earth combine, and what Heavenly Stems and Earthly Branches share together. However, the functions of Yin and Yang undergo various changes, appearing in a complex and different manner. Why is this so?
A: This is precisely what is called the governance of "Three Harmonies" (San He). The governance of Three Harmonies necessarily involves the integration of Qi, which must serve as the primary function. Sometimes it follows the Root Qi (Ben Qi), sometimes it follows the Mark Qi (Biao Qi); sometimes it conforms due to excess, or changes due to transformation. Although they differ, ultimately they all take use of Qi to honor the substance, rather than exhausting the substance to labor over things. For example, in the Five Movements (Wu Yun), Earth takes the lead and adds the Stem Jia. From Jia as Earth downwards, other Stems are not used. Yet, in years governed by Jia, Bing, Wu, Geng, and Ren, the Qi is still considered excessive; in years governed by Yi, Ding, Ji, Xin, and Gui, the Qi is still considered deficient. Although the Stems change, the Yin and Yang remain unchanged, indicating that the Stems are indeed not unused. The Si Tian (Heavenly Ruler) also alters the Branches, but Fire corresponds to Wu, Earth to Chou and Wei, Metal to You, meeting with the Annual Branch. This means being in the correct position and combining with its Qi. These are all cases where the original position is not changed, nor are the original Branches discarded. Generally speaking, the function of Yin and Yang combines two to become one, and uses three. Therefore, although the movement of Yin and Yang is a single entity, its dynamic changes each follow their own path. Following their own paths is how the subtle function of Yin and Yang is realized. All such variations of Qi through Three Harmonies are like this. Knowing their function removes doubt about their changes.
Q: When Si Tian and Yun Qi are used together, there are Tian Fu (Heavenly符) and Sui Hui (Annual Meeting), as well as Minor Five Movements, which are intermixed between Si Tian and Zai Quan (Earthly Sovereign). What is the reason for this?
A: The governance of the Three Harmonies of the Five Phases is applied everywhere and nowhere is it not Three Harmonies. For instance, in Chen and Xu years, Tai Yang Cold Water rules as Si Tian. Chen and Xu encompass the five positions of Jia, Bing, Wu, Geng, and Ren. Thus, the Five Movements also fully traverse the single position of Cold Water. Although Cold Water is singular, it has five variations. Within these five variations, the operations that circulate throughout the year each have their own Five Movements, similar to the intervals (Jian Bu) established within Si Tian. Since Major Five Movements interact with Si Tian, Minor Five Movements also interact with the intervals. This is also the natural way of Yin and Yang. The Annual Qi must prioritize Wood, thus starting with Shao Shao Jue (Minor Wood tone) and ending with Shao Shao Yu (Minor Water tone). The generative order of the Five Movements cannot be disordered. However, their function is subtle and less intense than the intervals, so the classics do not explicitly record diseases related to them, merely to make people aware of them.
Q: The Five Phases have five functions, each taking the lead. The Six Qi starts with Wind-Wood, Si Tian starts with Fire, Five Movements start with Earth, the generation of Five Phases starts with Water, and their completion starts with Metal. They cycle and can each take the lead. Is there any principle behind this?
A: This is the wondrous function of Yin-Yang creation, inconceivable. Speaking from the beginning of biological generation, it starts with Tian Yi (Heaven One). Tian Yi is Water. Water rises when warmed, so Fire follows. Fire and Water stir each other to form, so Wood follows. Wood grows firm and hard, so Metal follows. These four cannot be completed without Earth, so completion must rely on Earth. The sequence in the *Hong Fan* is thus, representing the origin of life. Regarding the Four Seasons and Six Qi, they must take the Year Virtue (Sui De) as the leader. The Year Virtue lies in Wood, so Wood begins at Jue Yin and reaches its official status at Yin month, thereby expressing the vital Qi and understanding human affairs. From Wood to Fire, to Earth, to Metal, finally stopping at Water, this is the order of the Four Seasons, involving growth, flourishing, transformation, gathering, and storage. The Five Movements take Earth as the leader because Heaven's Qi moves from the center, and Wu and Ji occupy the center to nourish all things. Thus, deducing from this Central Palace, the four cardinal directions surround it to execute its generative function. This concerns matters in Heaven. As for Si Tian taking Fire as the leader, it is because Shao Yin Minister Fire holds the dignity of an Emperor, ruling from above, to whom all look up. However, only when the Big Dipper's handle first points East does the Emperor descend. The Emperor emerges from Zhen (East), hence Fire is taken as the leader, and Jue Yin as the end. Roughly, the Three Yin form a group. Now Shao Yin is in the center, and Jue Yin is in front. Thus, one must pass through the Three Yang before Jue Yin comes last. Jue Yin is located at the Hai position, signifying termination. Speaking from the perspective of success, Metal and Wood are the beginning and end of generation and completion. They manifest the completion of all species and arrange the forms of all matter. This values not only the beginning but especially the end. Therefore, only when firmness and completion are seen are the forms of Water, Wood, Fire, and Earth fully prepared. This is the order of completing things, discussed from the perspective of their utility.
Q: In the smooth and reverse movement of Yin and Yang during the Four Seasons, there is a distinction between left and right. Why?
A: Yang moves upward from below, thus rotating left to become Spring and Summer. Yin moves downward from above, thus rotating right to become Autumn and Winter. Therefore, Spring, as the Vital Qi, moves westward, transforming its Gathering Qi into warmth. Summer, as the Flourishing Qi, moves northward, transforming its Visceral Qi into heat. Autumn, as the Gathering Qi, moves eastward, condensing its Vital Qi into coolness. Winter, as the Storage Qi, moves southward, condensing its Flourishing Qi into cold. Movement toward the northwest is smooth (Shun); movement toward the southeast is reverse (Ni). During Spring and Summer, the sun traverses the Northern Land and days are long; during Autumn and Winter, the sun traverses the Southern Land and days are short. This is also the order of Yin-Yang smoothness and reversal.
Q: The classics state that Yin contains Yang, and Yang contains Yin. Why?
A: Yin and Yang are originally united. Since the Supreme Ultimate (Tai Ji) moved to generate Yang and rested to generate Yin, Two Modes (Liang Yi) were established to oppose each other. This "one" where each is distinct is easily understood by people. Using movement and rest as drumbeats, and Yin and Yang as subtle functions, transforming the formless into the formed, establishing different forms from the same substance, Yin and Yang cooperate to drum the mechanism of transformation. This "united one" is difficult for people to understand. Therefore, tracing back to the Great Beginning, the origin of Yin and Yang stems from a single mechanism. Extreme stillness generates Yang, extreme movement generates Yin; Yin and Yang mutually generate each other. Tracing back to their established positions, the roots of Yin and Yang hide within each other's dwellings. Fire's embryo is in Zi, Water's embryo is in Wu; Yin and Yang mutually inhabit each other. Only when a person comprehends that the root of Yin and Yang is one can they know that Yin and Yang can be two.