Explanations of the Teachings of the Revered Ancestor

易道至微，包義至廣，仁者見仁，智者見智，易固具仁智矣，而見者則依人而殊。非貫通之，誠不明易之為易，而聖人之教不得全行於世，雖曰讀易無益也，故必先明易之本義。夫「易」者：賅象數以明氣，辨時位以明用，詳變化以明生，測順逆以明吉凶，徵名類以明動靜，驗二五以明終始本末，會天人以明性情道德。其含義無盡，致用不窮，其稱名不一，取類至廣，然有其始終焉：推事物之情，溯天地之道，以人立極，有其道也。故習易者有其例，不明其例，則莫知其旨，而例者，指象數也。

The Way of the Book of Changes is extremely subtle and its included principles are extremely broad, so the Great Treatise says, "The benevolent person sees it and calls it benevolence; the wise person sees it and calls it wisdom." The Book of Changes originally contains both benevolence and wisdom, but people's interpretations differ according to their own nature. If it is not integrated, one will truly not understand why the Book of Changes is called the Book of Changes, and the sages' teachings will not be fully practiced in the world. In that case, reading the Book of Changes would be of no benefit. Therefore, one must first understand the fundamental meaning of the Book of Changes. The term "Easy" refers to the comprehensive use of "images" and "numbers" to explain qi, distinguishing "time" and "position" to explain application, elaborating on change to explain the continuous generation of life, predicting favorable and unfavorable conditions to explain good and bad fortune, verifying names and categories to explain movement and stillness, examining the dual and the five (yin and yang and the Five Phases) to explain beginning and end, origin and outcome, and integrating heaven and humanity to explain nature, emotion, morality and virtue. Its meaning is endless, its use is infinite, its names are not limited to one, and its analogy is extremely broad, yet it has its own order. By investigating the nature of things, tracing back to the great Way of heaven and earth, and using human beings as a standard, this is its method. Therefore, studying the Book of Changes requires "examples" (general principles and rules). Without understanding these general principles, one cannot grasp its essence. The so-called general principles refer to images and numbers.

象數者，圖畫文言之所示也。不先求於圖畫文言，則不明象數；不明象數，則不知易之本體及其變化。若拘拘於經文，兢兢於名類，此為文藝之事，而非以極深研幾也。如乾者，必先求其圖之所示，何以為□；必先考其爻之所名，何以為九；必先溯其氣之所始，何以為陽；必先察其道之所存，何以為天。皆必徵於象數而後知之。知之而後可言其德，可名其用，可數其變化，可質其所分合，可因例而明其爻之所占、文之所釋，而後經文可得而釋也。此凡習易者均當如此。夫子韋編三絕，所用心亦如此，決非徒誦其經，熟其訓詁，即足了事者。而講易之先，必自例始；例明而後通貫一切，庶無惑於經文之義；此為講易第一事。

The concepts of "image" and "number" refer to the meanings revealed through diagrams and text. Without first seeking understanding from the diagrams and text, one cannot comprehend the principles of image and number; without understanding image and number, one cannot grasp the essence and transformations of the Book of Changes. If one merely focuses on the text and gets bogged down in terminology and categories, that is the approach of literary study, not "reaching the profound and examining the subtle." For example, the "Qian" hexagram must first clarify what its diagram represents and why its hexagram is drawn in that form (the original diagram is missing here); it must first examine why its line is called "nine"; it must first trace the origin of its energy and why it is considered "yang"; it must first investigate the underlying principles and why it is symbolized as "heaven." All these must be understood through the study of image and number. Only after understanding these can one discuss its virtues, its functions, its transformations, and its distinctions and combinations. Only then can one understand what each line represents and what the text explains, and only then can the text be properly interpreted. All those who study the Book of Changes should follow this approach. Confucius read the Book of Changes so thoroughly that he wore through the ropes binding the bamboo slips three times; his diligence was precisely in this, not merely memorizing the text or mastering the meanings of words. Therefore, before discussing the Book of Changes, one must first grasp the general principles; only after understanding the general principles can one comprehend everything and avoid confusion over the meaning of the text. This is the first essential matter in studying the Book of Changes.

夫易自伏羲氏以後，象數卦儀，傳之既久，因其用不同，而取義有異；故有連山、歸藏、乾坤三易之分；實以一為三，非有他易也。連山首艮以明人道，夏代承用之；歸藏首坤，以重地道，商承用之；乾坤首乾，以尊天道，周承用之。以所首不同，故取義各異，正與夏正建寅，商正建丑，周正建子，其義一也。非歲序異，歲首異耳。故明人道者，以人為先；重地道者，以地為先；尊天道者，以天為先。實則易道備天地人，先後雖殊，場道不異，殊其用耳。

The Book of Changes has been passed down since Fuxi, with its images, numbers, hexagrams, and rituals. Because of different uses, the meanings derived from it have varied, leading to the distinction of three versions of the Book of Changes: the Lianshan, the Guicang, and the Qiankun. In reality, these are three different forms of the same Book of Changes, not three separate books. The Lianshan begins with the Gen hexagram, used to explain human affairs, and was used during the Xia dynasty; the Guicang begins with the Kun hexagram, used to emphasize the earth's principles, and was used during the Shang dynasty; the Qiankun begins with the Qian hexagram, used to honor the heavenly principles, and was used during the Zhou dynasty. Because the first hexagram differs, the meanings derived also differ. This is similar to the way the Xia calendar took the寅month as the first month of the year, the Shang calendar took the丑month as the first month, and the Zhou calendar took the子month as the first month. It is not that the order of the year has changed, but only that the name of the first month has changed. Therefore, the one that explains human affairs places humans first, the one that emphasizes the earth's principles places the earth first, and the one that honors the heavenly principles places heaven first. In reality, the Book of Changes encompasses heaven, earth, and humanity. Although the order of precedence differs, the principles of the Book of Changes remain the same; the difference lies only in their application.

周雖重天道，而兼二代之制，故文王重演坎離之卦，以合三為一，而同於乾坤之易；乾坤之易，伏羲固已立制，而坎離之易，則文王為之紹述者也。後人名之曰「先天易」「後天易」，其實一體一用耳。

The Zhou dynasty, although emphasizing the heavenly way, also adopted the systems of the Xia and Shang dynasties. Therefore, King Wen reworked the trigrams Kan and Li, integrating the systems of the three dynasties into one, making them consistent with the Book of Changes based on Qian and Kun. The system of the Book of Changes based on Qian and Kun was already established by Fuxi. As for the Book of Changes based on Kan and Li, it was King Wen who continued and developed it. Later generations referred to them as the "Earlier Heaven Book of Changes" and the "Later Heaven Book of Changes," but in reality, one discusses the fundamental principles and the other discusses practical applications.

蓋乾坤易、明位者也；坎離易、用時者也；雖次序不同，而其為易也無異。以乾坤之易，不能外坎離，坎離之用，亦不能不本乾坤；二者相參，而後變化以大，不獨二易以合用，即三易亦由是以同功。此坎離之易，包括乎一切，而為天地既奠以後所不可少者，以其用之廣，而變化之神也；此習易者必先知之。知其一而求其二與三，則三二皆歸於一，以一概易，名符義當。誠哉聖人之心，足以通天地，並日月矣！

The "Qian and Kun" aspect of the Book of Changes deals with directions, while the "Kan and Li" aspect deals with timing and application. Although the order is different, both aspects belong to the Book of Changes without distinction. The "Qian and Kun" aspect cannot be separated from Kan and Li, and the application of Kan and Li cannot be done without relying on Qian and Kun. They complement each other, allowing for great transformations. Not only should these two aspects be used together, but all three aspects of the Book of Changes also achieve the same effect. The reason why the "Kan and Li" aspect can encompass everything and become an essential part after the establishment of heaven and earth is because of its wide application and mysterious transformations. This is something those who study the Book of Changes must first understand. Once one understands one aspect, seeking the others will eventually lead to the unity of three into one. Using this "one" to encompass the Book of Changes, the name and meaning are perfectly aligned. The wisdom of the sages is truly remarkable, capable of connecting heaven and earth and standing equal with the sun and moon!

故文周之後，夫子必兢兢焉以祖述之，而為文以著其義；使伏農暨文周之業，永垂無盡，此則夫子贊易之微志也。夫易有數義焉：以其至易，本於太一也，故自無始至有始，推之無盡，無不可知，此一義也。以其不易也，立本於中，致用於極，中極不變，永執其中，其道乃久，故能行變化而無息，主生成而不測，此一義也。以其變易也，順天地之消息，應氣數之盈虛，與時遷移，其道莫窮；故能握化之鈞，得循環之道；唯通以變，因適而宜，此一義也。

Therefore, after King Wen and the Duke of Zhou, the Master surely carefully continued their work, recording it in writing to reveal its principles, so that the achievements of Fuxi, Shennong, King Wen, and the Duke of Zhou would be perpetually transmitted. This is the profound intention of the Master in commenting on the Book of Changes. The character "易" contains several meanings. The first is "至易" (simplicity): it takes "Taiyi" as its foundation, so from no beginning to the emergence of a beginning, it extends endlessly, and nothing is unknowable. The second is "不易" (constancy): it establishes its root in "zhong" (the center) and extends its function to "ji" (the extreme). Zhong and Ji remain constant, and by always holding fast to this center, its way can endure, thus enabling it to carry out transformation endlessly and govern creation beyond measure. The third is "变易" (change): it follows the waxing and waning of heaven and earth, responds to the full and empty of qi, and adapts with the shifting circumstances, with the path never ending. Therefore, it can grasp the key of the workings of nature and comprehend the laws of cycles; only by being fully enlightened can one respond to change, and by adapting appropriately to each situation, one can achieve the right fit.

易之為道，有本末始終，有體用內外，包乎萬有，極乎無盡，推之無窮，而無為無不為。此至誠之德，中和之功，天人之所合，事物之所順；而明乎玄微，探乎繁嘖；至簡且易，至久且廣者也，此易之名與義也。

The Dao expressed in the Book of Changes has a beginning and an end, a root and a branch, a body and a function, an inner aspect and an outer aspect. It encompasses everything, reaches the utmost limitlessness, and is inexhaustible in its unfolding. It appears to do nothing yet accomplishes everything. This is precisely the virtue of "utmost sincerity" mentioned in the Doctrine of the Mean, and the effect of "harmony in the middle," the meeting point of heaven and humanity, the basis for the smooth operation of all things. It can illuminate the subtle and profound, and explore the complex and chaotic. It is both simple and easy, yet profound and vast. This is the meaning of the term "Yi" and its significance.

至易之為象，上日下月，日月者，陰陽之所昭，而天地之道所見者也。以天之道，由日而明，地之道，由月以見；日月代行，天地不息，此坎離代乾坤為主，而水火成陰陽之用。此在體用既合，情性同見之時，而後知乎天地之道，曲成之妙者也。故明易者，必先明坎離之易，由下溯上，由外及內，由人及天，皆必然之序，不可臘者也。

As for the formation of the character 「易」, it consists of a 「日」 on top and a 「月」 below. The sun and moon serve as the means by which yin and yang are revealed and the principles of heaven and earth become evident: the heavenly way is made clear through the sun, and the earthly way is made visible through the moon. The sun and moon take turns in their movement, and thus heaven and earth continuously generate and sustain life. This is why 「坎」 and 「离」 take the place of 「乾」 and 「坤」 in the central position, with water and fire embodying the function of yin and yang. Only when the essence and function are combined and emotion and nature are fully revealed can one understand the subtle aspect of the way of heaven and earth, which is to 「曲成万物」 (as stated in the Great Treatise, meaning to accomplish all things in a subtle and comprehensive way). Therefore, to understand the Book of Changes, one must first understand the part of the Book of Changes related to 「坎」 and 「离」. One should trace back from the lower to the upper, from the outside to the inside, and from human affairs to the heavens. This is the natural sequence and cannot be skipped or rushed.

且日者元陽之象，其體亦太極之象，故為□、即□，亦中字之形也；太極之體一，為萬有之母，而易自太極始。日者生物之根，凡物不得日之光熱則不生，是日即生物之母。勿者，古文物字；上日下勿，示生生之象，亦明天下萬物自生之源。其取意固精，而為文卻顯。故知日月為易，則知天地以陰陽而神其變化，亦即知乾坤之易，以坎離而明其功用也。

Now speaking of the "day" (日), it represents the original yang, and its essence is also the image of the Taiji. Therefore, the symbol it takes (the original text here has a missing diagram) is exactly the shape of the character "中" (center). The essence of Taiji is "one," which is the mother of all things, and the Book of Changes (Yi Jing) begins precisely from Taiji. The sun is the fundamental source for the growth of all things; without the light and heat of the sun, nothing can grow, so the sun is the mother of all living beings. "Wu" (勿) is the ancient form of the character "物" (thing); the character "Yi" has "day" on top and "wu" below, showing the image of continuous generation and also indicating the origin from which all things in the world arise on their own. Its meaning is indeed profound, and its character formation is very clear. Therefore, understanding that the sun and moon together form the character "Yi" means understanding that heaven and earth bring about changes through yin and yang, and also understanding that the Yi of the Qian and Kun is manifested through Kan and Li.

知□為易，則知天下萬物，莫不生於太一，育於元陽，而易之為教，莫外於溯萬有之始終，推萬物之生成長育，更由是以明天道人道之體用，及夫事物變化消息之數運也。故易辭雖簡，為義極宏，其道至深，為言必備。苟欲洞明其故，則固不外求之象數與文辭也；而易之象數，則盡乎形氣之精；易之文辭，則概乎義理之至。不深研而通其趣，則必有所滯；不廣征而匯其歸，則必有所失。此見仁見智之說，所由來也，習易者可不勉哉！

Understanding that symbol (the original text's diagram is missing) is the "Yi," one also understands that all things in the world arise from "Taiyi" and are nourished by "Yuanyang." As a means of education, the "Yi" is essentially about tracing back the beginning and end of all things, investigating the generation and growth of all things, and from there explaining the principles and applications of the Way of Heaven and Humanity, as well as the numbers and movements of change and transformation in things. Therefore, although the words of the "Yi" are concise, their meaning is extremely vast; its principles are very profound, yet its expressions must necessarily be complete. If one wishes to thoroughly understand the reasons behind it, in the end, it can only be sought from both the symbolic representations and numerical calculations and the textual expressions. The symbolic representations and numerical calculations of the "Yi" exhaust the subtle aspects of form and qi; the textual expressions of the "Yi" summarize the ultimate meaning of principles. Without deep study and understanding of its subtleties, one will inevitably encounter obstacles; without extensive evidence and summarizing its overall essence, one will inevitably miss something. This is the origin of the saying "seeing it as benevolence or wisdom," how can those who study the "Yi" not strive diligently!

夫易：明數者也，而數本乎氣，氣本於陰陽，陰陽本於太極，故太極為易之始。太極者，一也，其初無名無形，由元氣之凝而為光；光生氣，氣成形，形成質，故物之始生，必先有氣。斯氣也，流行天地之間，分合萬有之體，而不可見。

The Yi is the study of numbers. Numbers are based on qi, qi is based on yin and yang, and yin and yang are based on the Taiji. Therefore, the Taiji is the beginning of the Yi. The Taiji is referred to as "one." It was originally nameless and formless, and from the gathering of primordial qi, it transformed into light. Light produced qi, qi condensed into form, and form coalesced into substance. Therefore, when all things first began to arise, there must have been qi first. This qi flows throughout the universe, separating and combining the forms of all things, yet itself remains invisible.

見其形質焉，因氣之分合多少偏全，而形質不齊，故數不等而象不一，求其象而後知其數，明其數而後辨其氣。氣有陰陽，數有奇偶，因分合而有四五，因偏全而有善惡；此氣之變化也。因生物之時地有多寡，因境遇之變遷而有大小；此數之消長也。因所受之殊，而形質有殊；因所合之異，而性情有別；此象之進退也。

What people can see are form and substance: because the division and combination of qi varies in quantity and in completeness, forms and substances differ, so the numbers vary and the images differ. One must first obtain the image in order to know the number, and then clarify the number in order to discern the qi. Qi divides into yin and yang, number divides into odd and even; due to differences in division and combination there are four (the Four Symbols) and five (the Five Phases), and due to differences in completeness and partiality there are good and evil, which are changes in qi. Due to differences in time and place of birth, there are variations in quantity, and due to changes in circumstances, there are differences in size, which are the waxing and waning of numbers. Due to differences in what is received, forms and substances differ, and due to differences in what is combined, temperament and disposition differ, which are the advancement and retreat of images.

蓋氣自太極以下日分，分而仍合；故兩儀、四象、五行、皆以次名，數自太一以下，亦漸散，而仍復聚，故天一地二、至天九地十、推而五十、六十四、百四十四、二百一十六、而萬一千五百二十之數以別，象自太極以下，由氣數之推移變化，而諸物生成，名類日多，反覆日眾，以仍循環終始，故八卦六爻之互相乘除，太陰少陽之互相推化，以成萬物之形，類萬有之情，名萬事之制，而不可窮盡，此皆順乎生化之序，有不期然而然者。

The qi originates from the Taiji and is divided layer by layer downward, yet remains united, thus giving rise to terms such as "two principles" (liang yi), "four images" (si xiang), and "five phases" (wu xing) in sequence. Numbers also descend from "Taiyi" and gradually disperse, yet remain gathered, thus leading from "Heaven One, Earth Two" up to "Heaven Nine, Earth Ten" as recorded in the "Great Treatise" (Xici Shang Wen) regarding the numbers of heaven and earth. From there, it is further extended to the great derivation number of fifty, the sixty-four hexagrams, one hundred and forty-four (Kun's number), two hundred and sixteen (Qian's number), until ten thousand one hundred and fifty-two (the number representing all things), each with its distinct classification. The images originate from the Taiji and are generated through the movement and transformation of qi and numbers, leading to the emergence of various things, with their names and categories increasing day by day, their interweaving becoming more intricate, yet still following a cycle with beginning and end. Therefore, the six lines of the eight trigrams interact with each other through multiplication and division, while the Taiyin and Shaoyang interact and transform, thus forming the forms of all things, distinguishing the conditions of all things, and establishing the standards for all affairs, without end. All these follow the order of generation and transformation, occurring naturally without intention.

故總而言之：則一生二，二生三，三生萬物，分而言之，則太極以下，氣數與象，各以類別，不可勝紀。以自上而下，則言之如此；如自下溯上，則必就其已見者征之，此求象為第一步。因象者於外，存於現在，耳之所聞，目之所見，手足之所執持者，固易為徵。徵其象則得其數與氣，而後因其例，以辨其吉凶福禍；循其時地，以辨其道德性情，而後行止有方，動定有則，而用乃著，而道乃彰，而後聖人立教之心可見矣！故習場莫先於象數，明象數莫先於例。易之明例，實習渴之下手處，故講易必自例始，以其已知，求未知也。

In summary, this is what the Book of Dao (Laozi) says: "From one comes two, from two comes three, and from three come all things." When considered separately, below the Taiji, the qi, numbers, and images are categorized into different classes, and there are too many to count. Going from above to below, the situation is as described; but if we want to trace back from below to above, we must use the already manifested things as evidence. At this point, seeking the image (xiang) is the first step. Because the image is outside, existing in the present, it is something that can be heard by the ears, seen by the eyes, and held by the hands and feet, and thus is easy to verify. By examining the image, we can determine its number and qi; then, by following the general principles, we can distinguish between good and bad fortune, and by considering time and place, we can discern moral character and temperament. After this, action and stillness have direction, movement and stability have rules, and function becomes evident, the great Dao becomes clear, and the intention of the sage in teaching can be seen. Therefore, studying the Yi (Book of Changes) has no priority over the images and numbers. Understanding the images and numbers has no priority over the general principles. Truly understanding the general principles is the starting point of studying the Yi, so explaining the Yi must begin with the general principles—using what is already known to seek what is unknown.

夫易自伏羲畫卦，分列陰陽以定其位，重為六爻以明其時；乾坤為體，易行其中，乾坤成列，易立於中，二者體用之分，時位之辨，相錯以行，相交以變，生生不已，變化無盡。故由八卦而成六十四，六爻而推至三百八十四，皆本一氣循環，二五互用，以成其象，以寓其數，以行其氣。

The Book of Changes has been in existence since Fuxi created the eight trigrams. It divides yin and yang to determine the positions of each line, and combines three lines into six lines to show the time of each line. Qian and Kun are the fundamental principles; the Book of Changes operates within them. The Great Treatise says, "When Qian and Kun are arranged, the Book of Changes is established within them." Qian and Kun have distinctions between principle and function, and between time and position. They intermingle in operation and intermingle in transformation, continuously generating and transforming endlessly. Therefore, from the eight trigrams comes the sixty-four trigrams, and from the six lines comes the 384 lines. All of this is based on the cycle of one breath, the mutual interaction of yin and yang and the five phases, used to form its images, to embody its numbers, and to move its qi.

故太極既立，自生兩儀；卦象既成，自生爻象；自然推衍者也。由乾坤定位之易，而見卦位之序；由坎離中立之易，而見卦氣之時行，變化雖多，次序不亂，皆二五所生化，順乎天地萬物之次，而相交合五生成者也。故欲知生化之跡，必列象而觀之，此圖畫為所必重也。故習易必先將易之圖象，觀察明晰，如乾坤定位之圖等，一一列前；審其生化之序，及其推移之數，而後得其卦之由來，此固為第一事也。

Therefore, once the Taiji is established, the two principles naturally arise; once the hexagrams are formed, the lines naturally emerge—these are all naturally derived. From the "Qian and Kun establishing their positions" aspect of the Book of Changes, one can see the order of the hexagram positions; from the "Kan and Li occupying the center" aspect, one can observe the movement of the hexagram energies with the seasons. Although changes are numerous, the order remains unconfused, all arising from the generation and transformation of yin and yang and the Five Phases, following the sequence of the universe and interacting to produce all things. Therefore, to understand the traces of generation and transformation, one must arrange the images and observe them, which is why diagrams are given such importance. Thus, studying the Book of Changes must first involve clearly understanding its various diagrams, such as the "Qian and Kun positioning diagram," and displaying them in order, examining the sequence of generation and transformation and the numerical progression, only then can one clarify the origins of each hexagram. This is the fundamental task.

讀易須先明易例：以其敷辭有定，陳象不二，必通其義，而後明其旨，必抉其情，而後達其用。如乾□，天也、父也、之例，必先熟記之，則卦中有乾象，或通乾象；及其比偶反類之象者，皆有孚於乾之義，即有類於乾之情，則其為象，必同於乾之物；如天也、父也、之類，此易示象之例，有不易者也。又如乾之卦辭「元享利貞」，其六爻之辭各異，而皆有其物與事以象之，則各卦中如有乾之辭，及其爻之辭，或比偶反類之辭，皆與乾通其義；必合對參之，以明其所指，而後知其辭之用，此易辭之例，必通解者也。

To study the Book of Changes, one must first understand its general principles. Because the Book of Changes uses fixed expressions and clear symbolic representations, one must understand its meaning to grasp its purpose, and must uncover its actual significance to comprehend its practical applications. For example, the hexagram Qian (Heaven) represents Heaven and Father; this general principle must be memorized first. Then, any other hexagram that contains the image of Qian, or is related to it, or is compared with it, paired with it, opposite to it, or similar to it, will conform to the meaning of Qian and be close to its characteristics. Therefore, the images it takes will necessarily be the same as those symbolized by Qian, such as Heaven and Father. This is the general principle of the Book of Changes in displaying images, which is fixed and unchanging. Another example is the hexagram statement of Qian, "Original, Auspicious, Advantageous, and Correct." Although its six line statements are different, each has a corresponding object or event as its symbol. Therefore, if any hexagram contains the statement of Qian or a line statement corresponding to Qian's lines, or if the statements are compared, paired, opposite, or similar, they will all be connected to the principles of Qian. One must compare and examine them together to understand what they refer to, and then one can know how to use these statements. This is the general principle of the Book of Changes' statements, which must be fully understood.

習易貴乎通，而用易在乎熟，苟執而不通，習而多忘，則何以窮天下之變，盡易道之蘊哉？蓋易者：以簡御繁，以顯探微者也，因其為用至廣，言文難備；為道至大，事物同賅，則不得不操其本，用其極，以不二之道，成不測之功；以至易之文，成至神之用，此所以僅六十四卦，三百八十四爻，而盡天下之事物與變化也。不先明此，則不能窺聖人制易之心，亦不能全易道之用，則雖治易終無益也。故貴在能熟其辭而通其象。

Learning the Book of Changes is valuable only when one can grasp its overall meaning, and using it depends on thorough mastery. If one rigidly adheres to a single aspect without understanding the whole, then after learning it, one is likely to forget most of it, and how can one then explore the changes of the world and fully comprehend the profound meaning of the Book of Changes? The Book of Changes is a book that uses simplicity to manage complexity and moves from the obvious to the subtle. Because its application is very broad, words and characters cannot fully express it; its principles are vast, encompassing all things, so one must grasp the fundamental principles and apply them to the extreme, using a single, pure method to achieve unpredictable results, and using extremely simple characters to produce extremely profound effects. This is why only sixty-four hexagrams and three hundred and eighty-four lines are sufficient to cover all things and changes in the world. Without first understanding this, one cannot glimpse the intention of the sage in creating the Book of Changes, nor can one fully utilize the principles of the Book of Changes. In that case, even if one studies the Book of Changes, it will ultimately be of no benefit. Therefore, the key lies in being able to read its words fluently and understand its images thoroughly.

易之為用，有獨用者，有合用者，有對偶者，有推移者；有反逆相成者，有正順相制者，其類不一，其例至多；則可就其象驗之。如各卦各爻，均有獨用之例，而相合亦成其用。其對偶推移，順逆正反，則成其生克變化之用，此當就其成例測之。

The use of the Book of Changes involves methods that take individual elements, combine them, pair them, follow sequences, oppose and complement each other, and regulate and constrain each other. There are many different types and rules, all of which can be verified through the images. For example, each hexagram and line can be used individually according to established norms, and they can also achieve their purposes when combined. As for opposing and complementary movements, following and reversing sequences, these form the functions of mutual generation and mutual control, leading to continuous change. All of these should be inferred according to existing established examples.

蓋乾坤二卦，各獨立而為天地父母；合則如泰否，其用不同，對偶推移，則如復姤遯臨之類；相生克以成變化，則如剝復損益既未濟之類，皆有定例可尋者也。至其比例交錯，由此通彼，由上化下，則如咸恆之乾坤，益損之離坎，各極其變而成其用，亦自成例；故必列象，觀其分合變化，驗其生克消息，而後得其用焉。

The trigrams Qian and Kun represent Heaven and Earth when they are separate; when combined, they form the hexagrams Tai and Po, each with different applications. Those that represent opposing transformations, such as Fu, Gu, Duan, and Lin, are of this kind. Those that form changes through mutual generation and control, such as Bo, Fu, Shen, Yi, Ji Ji, and Wei Ji, also follow certain rules. As for cases where things are compared and interwoven, leading from one to another and from above to below, such as the hexagrams Xian and Heng derived from Qian and Kun, and Yi and Shen derived from Li and Kan, each pushes transformation to its extreme and achieves its function, forming their own regular patterns. Therefore, one must arrange the images, observe their combinations and transformations, verify their generation and control, and then be able to grasp their applications.

故易有乾坤中立之序圖，有坎離上下之序圖，有其本宮變化之序，有依對偶推移之序，無非為極其用也。必先於其同以求其異，於其異以證其同，而後知其變化由來，生克消息之例也。是以習易，非僅釋文義，諳象一變為坎坎離上下之序圖，其原因如何？成用如何？而後知聖人易教之本旨，與吾人習易之何為。

Therefore, the Book of Changes has sequential diagrams such as "Heaven and Earth in the center" and "Kan and Li living apart above and below," as well as sequences arranged according to their original positions and those based on opposing transformations. All of these are meant to fully utilize its applications. One must first find differences from similarities and then verify similarities through differences, in order to understand the origin of changes and the principles of generation, overcoming, and decline. Therefore, studying the Book of Changes is not merely about explaining the meanings of the text; one must also clarify why the hexagrams change from "Heaven and Earth establishing positions" to the sequence of "Kan and Li above and below," what the reasons are for such a change, and what purposes are achieved thereby. Only then can one understand the fundamental intent of the sages in using the Book of Changes for teaching, as well as the true purpose of studying the Book of Changes.

易之八卦為綱，其所生化五十六卦為目，而乾坤二卦，又綱之綱，以各卦皆自是出，即萬物生於五行，五行成於二氣也。由其數言，八卦者生成之數，五十六卦則相生相制之數也，萬物雖眾，皆包於六十四卦，則一卦之分合變化，所賅者多矣！故必詳徵於爻。爻者本於乾坤之□、□，即數之九六也，無論何爻，不外□、□，即言萬物萬事，不出九六之數與陰陽之氣也。

The Book of Changes takes the Eight Trigrams as its main framework, and the remaining fifty-six trigrams derived from them as its details. The trigrams Qian and Kun are the main trigrams within the framework, as all other trigrams are generated from them. This is analogous to how all things arise from the Five Phases, and the Five Phases themselves are formed by the interaction of yin and yang. Numerically, the Eight Trigrams represent the generating numbers, while the fifty-six trigrams represent numbers that are both generated and restrained. Although all things are numerous, they are all included within the sixty-four trigrams. Therefore, the division and transformation of each trigram must be carefully examined. The lines (yao) originate from the two line symbols of Qian and Kun, that is, the yang line and the yin line. Numerically, these are represented as 'nine' and 'six'. No line can be outside these two, meaning that all things are contained within the numbers nine and six and the energies of yin and yang.

由其合觀之，則變化無盡；由其分言之，不過天地所賦之一耳。故乾坤為天下之樞機，而□、□為天下之本氣；九六為天下之總數，實為生化之所始終者也。雖究其生化，有不可盡，而溯其本始，則不離於是。是即中庸所謂天地之道不二，而生物不測也。故易者：示天地萬物終始者也。無論何物何事，莫不包於易中，即溯無始，以迄天地之滅，皆由易象盡之矣！

When combined, their changes are endless; when separated, they are merely the single principle given by heaven and earth. Therefore, Qian and Kun are the key elements of the world, the yin and yang lines are the fundamental qi of the world, and the numbers nine and six are the total numbers of the world. They are truly the beginning and end of generation and transformation. Although the process of generation and transformation is inexhaustible, tracing back to its origin cannot be separated from these. This is what the Doctrine of the Mean refers to as the way of heaven and earth being singular and unchanging, thus enabling the transformation and nurturing of all things beyond measure. Therefore, the Book of Changes is a book that reveals the beginning and end of heaven, earth, and all things. No matter what object or matter there is, it is all included in the Book of Changes. Even if we go back to the beginning without origin, or forward to the time when heaven and earth are destroyed, we can fully explain it through the images of the Book of Changes.

如以六十四卦次第列之為圖，即足以示天地世界之終始，即自乾坤以迄既未濟，其推移轉換，實一世界自然之序，而縮言之，即一人終始生化之例。其為變化者，則有方圓圖與歲序圖，及八宮之序，皆與經中次序相證，以互為用：因大數雖有定例，而變化甚多；必合各圖而後知其變例。如後人京氏之八宮，焦氏之歲序，與邵氏所傳於道家之方圓圖，皆易中自具之例，為推其變化，以與經本次序相證者也。

If the sixty-four hexagrams are arranged in order to form a diagram, it is sufficient to display the beginning and end of the universe: from the hexagram Qian (Heaven) and Kun (Earth) up to Ji Ji (Completion) and Wei Ji (Non-Completion), the transition and transformation in between truly represent the natural evolution of the world; in a smaller sense, it is also an example of a person's life from birth to death and the cycle of generation and decay. The forms that illustrate change include the "Square Diagram," "Circular Diagram," "Annual Sequence Diagram," and the order of the Eight Palaces, all of which correspond with and support the sequence of hexagrams in the classic text. Because although the great numbers have fixed rules, there are many changes within them, and one must refer to various diagrams to understand these variations. For example, the Eight Palaces hexagram sequence by Jing Fang, the annual sequence by Jiao Yanshou, and the Square and Circular Diagrams passed down from Daoism by Shao Yong, are all inherent principles in the Book of Changes, intended for the derivation of change and to verify the sequence in the classic text.

故大之足以盡宇宙之象，小之足以合歲時之紀，即一人一地一時之事，亦由是足以占之，此則因天地生化自然之例，固如是也，即其變例，亦不出於各圖之序，由正證變，皆如指掌；故可以明知未來，通達既往，而盡其變化，致其用也。是易之象雖簡，而含義無窮，習易者必詳求之，始全其用；而其道總不外往復於六十四卦之內也，其變例為圖尚多，此舉其至要而已傅者耳。習易之先，務熟記之。

If looked at from a grand perspective, it can fully encompass the phenomena of the universe; if looked at from a small perspective, it can fully correspond to the principles of the four seasons in a year. Even the affairs of a person, a place, or a moment can be predicted based on it. This is because the natural principles of generation and transformation of heaven and earth are inherently structured this way. Even its variations do not go beyond the order established by the diagrams. By using the standard examples to verify the variations, everything becomes clear as looking at one's own palm. Therefore, one can clearly foresee the future and thoroughly understand the past, fully grasp its changes and fully utilize its applications. It is evident that although the images in the Book of Changes are simple, their meanings are infinite. Those who study the Book of Changes must carefully explore them in order to fully realize their functions. The principles of the Book of Changes are always within the sixty-four hexagrams, constantly changing and recurring. There are many diagrams that illustrate variations, but here we only mention those that are most important and have already been passed down. Before studying the Book of Changes, one must memorize them thoroughly.

夫子命將易經要義，先為講釋，俾讀易者深解古聖演易之旨；文周說易之心，庶明儒教傳易原由，而知堯舜以來歷聖授受之薪傳要義。夫易自文王重演，周公繼之，夫子集其大成；而經文大明，義理大著；讀易者宜將繫辭、說卦、序卦、雜卦諸章，與全經，俱明解無遺，然後得聖人演易之旨，及吾人習易之用也。

The Master ordered first to explain the essential meaning of the Book of Changes, so that those who read the Book of Changes may deeply understand the purpose of the ancient sages in deriving the Book of Changes, and the intention of King Wen and the Duke of Zhou in explaining it. Thus, they may clarify the origin of Confucian transmission of the study of the Book of Changes, and know the essential teachings passed down by sages from Yao and Shun through the ages. The Book of Changes was first re-derived by King Wen, then continued by the Duke of Zhou, and finally synthesized by the Master, thus making the text of the Book of Changes clearly established and its principles greatly evident. Those who read the Book of Changes should explain all the chapters including the Great Treatise, the Explanations of the Trigrams, the Order of the Trigrams, and the Miscellaneous Trigrams, without any omission, so that they may understand the purpose of the sages in deriving the Book of Changes and the practical use of studying it.

四傳詳於易例，為輔翼易經之文，不讀四傳，不明易之為教也；故夫子於訂易時，特揭之，為易經參解以授弟子，俾明易之為易，故讀易必及四傳；易象至簡，卦辭亦略；欲通其用，舍先求之四傳，不能測其端倪。

The four commentaries, the Great Treatise, the Discourse on the Hexagrams, the Order of the Hexagrams, and the Miscellaneous Hexagrams, explain in detail the general principles of the Book of Changes. They are the supporting texts for the Book of Changes. Without reading these four commentaries, one cannot understand what the Book of Changes is as a means of moral instruction. Therefore, the Master deliberately included them when he compiled the Book of Changes, to serve as supplementary explanations for his disciples, enabling them to comprehend why the Book of Changes is called the Book of Changes. Thus, reading the Book of Changes necessarily involves studying these four commentaries. The images in the Book of Changes are extremely simple, and the statements of the hexagrams are also concise. To understand their application, one must first study the four commentaries, otherwise one will be confused.

蓋易起於上古，為時久遠，文字未興，雖具其象，亦如河圖、洛書，僅演其點畫而已，經神農軒轅以迄唐虞，代有增易，文字既制，政教益明，於易象之下，均加之演詞以著其義。因初傳於語言，難留久逸，相習固有師授，而易代輒忘；相用固有成規，而易地輒異，以至於夏商二代，各沿所習，各本其制，而有連山之易，歸藏之易，其取用既殊，而為義亦不一矣！

The Book of Changes originated in ancient times, its origins long ago. At that time, writing had not yet emerged, although there were already hexagrams, they were like the Yellow River Chart and the Luo Writing, merely arranging dots and lines. From the time of Shen Nong, the Yellow Emperor, through the Xia and Shang dynasties up to the Tang Yao and Yu Shun, each generation added and modified them. After writing was created, political orders and moral teachings became clearer, so they added explanatory texts beneath each hexagram to clarify their meanings. However, since the original transmission was oral, it was difficult to preserve for long. Although teacher-student transmission ensured continuity, changes in dynasties often led to loss of knowledge. Although using the tradition had its established ways, differences arose when applied in different places. By the time of the Xia and Shang dynasties, each followed its own tradition and based itself on its own system, thus giving rise to the Yi of Lianshan and the Yi of Guicang. Since their methods of use differed, the principles they established also varied.

至文王取而重演之，以成今傳之易，因恐後人疑其同異，忘其本來，始詳著其詞，以明其教，此四傅之作固為傳易為教者也。時代既殊，傳述又異；前之易者，徒存其象，今之詞者，乃備其文，故易道至周始昭，至夫子始定為經。

King Wen took them and re-examined them, thus making the Yi Jing as it is passed down today. Because he feared that later generations would be confused by the differences among various schools and would forget the original form, he began to write detailed explanations to clarify this teaching system—the four commentaries were originally written to transmit the Yi and to establish a teaching method. Since the times are different, the transmission has varied: the ancient Yi preserved only the images, while the present-day words complete the text. Therefore, the principles of the Yi became clear during the Zhou dynasty and were established as a classic in the hands of the Master.

夫子本文周之作，加以所習，而擴其義，敷詞具象，以次其序，明變著用，以列其圖，而後易之為易，有跡可尋，有文可讀，有圖可驗，有變化可征；不似前日之奧窈難稽，同異莫辨矣。故易教實成於夫子，而易義則備於四傳之文；欲知易者，必先知此，而後可進而求之也。

The Master based himself on the writings of King Wen and the Duke of Zhou, adding his own learning to elaborate on their meanings, arranging the words, listing the hexagrams in order, explaining changes and showing their applications through diagrams. Since then, the Book of Changes has become traceable, readable, verifiable through diagrams, and capable of being studied for its changes, unlike before when it was obscure and indistinct. Therefore, the actual teaching of the Book of Changes was completed in the hands of the Master, while its meanings were fully elaborated in the writings of the Four Transmissions. Those who wish to understand the Book of Changes must first realize this, and only then can they proceed further in their study.

易之起源，非乾坤也：蓋溯乾坤而上，則太極是也，然易有太極，是生兩儀之語，不見於經而見於傅；故必讀傅始知之也。易之為教，非言休咎已也，而在因休咎以悟性命，以道在人為性，易明人道，始於性善，「而繼之者善，成之者性」之語，亦詳傅中。

The origin of the Book of Changes is not merely the trigrams Qian and Kun: tracing back further than Qian and Kun leads to the Taiji. However, the statement "The Book of Changes has the Taiji, from which the two principles arise" is not found in the classic text but in the Great Treatise of the Upper Transmission. Therefore, one must read the transmission to understand it. As a means of education, the Book of Changes is not only about fortune and misfortune, good and bad; it is about using these to comprehend human nature and destiny. Because the Way manifested in human beings is called "nature" (Xing), the Book of Changes explains human conduct starting from the concept of "benevolent nature." The sentence from the Great Treatise of the Upper Transmission, "What is continued is goodness, and what is completed is nature," is also fully recorded in the transmission.

易之言數，始於圖書；自天一至地十，皆天地生成本數，而天一地二，大衍之數五十之語，亦在傳中；易之為用，以其變也；變始於錯綜參伍，以生化各卦：而參伍以變，錯綜其數之義，亦詳傳中。易之同異，在於序圖；以其本末始終，上下內外，各有其用，故有體有用，有同有異；而天地定位，帝出乎震，各方位序圖之說，亦詳傳中。

The Book of Changes deals with numbers, beginning with the Yellow River Chart and the Luo Writing. From "Heavenly One" to "Earthly Ten," these are the fundamental numbers generated by heaven and earth. The passage in the Great Treatise of the Upper Transmission, "Heavenly One and Earthly Two," as well as "The number of the Great Transformation is fifty," are all included in the transmission. The usefulness of the Book of Changes lies in its ability to change; change arises from "interweaving and combining," thus generating all the hexagrams. The meaning of "by combining and interweaving, numbers are transformed" in the Great Treatise of the Upper Transmission is also fully explained in the transmission. The differences and similarities among various schools of interpretation of the Book of Changes depend on the order of the hexagrams. Since beginning and end, upper and lower, inside and outside each have their own uses, there is both form and function, as well as both similarity and difference. The sections in the Discourse on Hexagrams, "Heaven and Earth are positioned" and "The Emperor arises from the震 (Thunder)," which discuss various diagrams of directional order, are also fully explained in the transmission.

易之遞嬗，大別有三：時代以殊，名類遂異；如連山、歸藏之易，次序不同，即體用生化之序，與男女之別，消長之象；其類皆異，其名皆殊；而本宮變化，與序卦次第，及連山、歸藏之首末位次，亦皆詳傳中。

The transformation and evolution of the Yi (Book of Changes) can generally be divided into three types: as times differ, the names and categories also change accordingly. For example, the two other books of Yi, the Lianshan (Continental Mountain) and the Guicang (Return to the Treasury), differ in their sequence of hexagrams. Therefore, the order of generation and transformation, the distinction between male and female, the waxing and waning images, and the categories all differ, as do their names. Moreover, the changes within each hexagram's own palace, the sequence of the Xugua (Order of Hexagrams), and the initial and concluding positions of the hexagrams in the Lianshan and Guicang are all detailed in the transmitted texts.

至如易之門戶，八卦之本義，六十四卦之時氣，與天地人所象之名類；少長老幼之期，上下內外之位，皆自有所合。一歲之遷移，八方之分合；古今世界之終始，與人事吉凶禍福之占驗；莫不詳於傅中。若不熟於傳，則中智以下，決不能探天地之妙，測陰陽之神；而以達於性命之源，明於行止動靜之道矣！故傳之作，為教後人之習易也。

As for the "doors" of the Book of Changes, the original meanings of the Eight Trigrams, the corresponding seasons and climatic conditions for each of the sixty-four hexagrams, and the names and categories of the phenomena represented by Heaven, Earth, and Humanity, as well as the corresponding periods for youth, middle age, old age, and childhood, and the positions corresponding to upper and lower, internal and external, all have their respective correspondences. The changes of the seasons throughout the year, the division and combination of the eight directions, the beginning and end of the world through time, and the divination of fortune and misfortune in human affairs are all thoroughly recorded in the commentaries. If one is not familiar with the commentaries, then those with average intelligence or below will absolutely be unable to grasp the profound mysteries of Heaven and Earth, comprehend the wonders of yin and yang, and thus understand the origin of life and death and the principles of movement and stillness. Therefore, the writing of the commentaries was precisely to teach later generations how to study the Book of Changes.

人求明易，不先明於傳文，是雖日讀經，恐無益於事；故夫子以其所得，指出其要，而集其義，為傳於經之前後，其循循誘人之心，足千古矣！雖其言得之先聖，非夫子一人所為，而其編訂之功，實為繼往開來之聖，讀者其毋負夫子之心焉爾。

A person wishes to understand the Book of Changes, but if he does not first clarify the transmitted interpretations, then even if he reads the classic text every day, it may not be of much use. Therefore, the Master summarized his insights and compiled the meanings into the transmitted text, arranging it before and after the classic text. His patient and gradual guidance for future generations is sufficient to serve as a model for all time. Although these words come from previous sages, not solely from the Master, his contribution in compiling them is indeed the work of a sage who connects the past with the future. Readers should not辜负 the Master's sincere intention.

且卦之象氣與數，必視其變化，而後得其未來，若僅執現象，則往復者不可知，將何以窮神知化哉？故通易必參全易之變化，非就一卦六爻之象，既足得其用也。又易者，因器明道者也，器可見，道不可見，必因有形以溯無形；有形者現具之象，無形則在無象之中，然棄有以求無，亦不得也：必求諸有而不執其有，方得其無焉，而非經文所盡也，必廣徵於先後天之圖，與本宮之序，及序卦之詞，而後知之，故必徵於傳文也。

Furthermore, the qi and numbers symbolized by the hexagrams must be observed through their changes before one can predict the future. If one only focuses on the present phenomena, the principle of cyclical repetition cannot be understood, and how can one speak of the saying in the "Great Treatise" part of the "Commentary" that "to exhaust the divine and know the transformation"? Therefore, to understand the "Book of Changes," one must refer to all its changes, not merely the images of a single hexagram with its six lines. Moreover, the "Book of Changes" uses tangible objects to explain the great principles. The objects are visible, but the principles are invisible; one must use the visible to trace the invisible. The visible is the present image, while the invisible is hidden within the absence of image. However, abandoning the "visible" to seek the "invisible" is also unattainable. One must seek the "visible" but not be attached to it, in order to reach the "invisible." These points cannot be fully explained by the text itself. One must widely consult the diagrams of the Earlier Heaven and Later Heaven, as well as the order of the palace and the words of the "Sequence of Hexagrams," before one can comprehend them. Therefore, one must seek evidence from the transmitted texts.

如先後天之圖，不見於經；即就乾坤之序，亦不知其位。唯「天地定位」一節，言先天八卦之位；「帝出乎震」一節，言後天八卦之序，皆足以證經文之不及者。如乾坤之序，為今易所定，始於乾，終於未濟，此固讀經可知者。而其本宮之序，則不在經中，又非徵於傳文不可。傳有云：「歸妹，女之終也」，乃明本宮之始終。

For example, the "Earlier Heaven Diagram" and "Later Heaven Diagram" are not depicted in the text; looking only at the sequence of trigrams following Qian and Kun, one cannot determine the positions of the eight trigrams. Only the passage in the "Commentary on the Changes" stating "Heaven and Earth are positioned, mountains and marshes communicate through the air" refers to the positions of the Earlier Heaven Trigrams; and the passage "The Emperor arises from Zhen, harmonizes with Xun" refers to the sequence of the Later Heaven Trigrams. These two passages are sufficient to explain what is not mentioned in the main text. As for the order of the trigrams, it is determined by the current version of the "Zhou Changes," beginning with Qian and ending with Wei Ji. This is something that can be known by reading the main text. However, the order of the eight trigrams within their respective palaces is not mentioned in the main text and must be verified from the commentary. The "Miscellaneous Changes Commentary" states "Guimei, the end of the female," which clearly indicates the beginning and end of the order of the eight trigrams within their respective palaces.

蓋序卦之次序，本於後天八卦之生化，而為用也；本宮之次序，則本先天八卦之生化，而為體也。體靜象坤，故歸妹為坤道之盡；後天用陽，而動象乾，故未濟為乾道之終。二者終始各異，致用亦殊，而必由傳考之，始得明其故。不特此也，連山首艮，歸藏首坤，六十四卦之序各異，即方圓與歲序圖皆不一。凡由乾坤變化而生者，皆有定序，而經但就文王所定者列之；若不徵於傳，則他易圖皆不得知。不獨不備於用，而經中各爻辭，恆有取前各易之舊者，其義亦難索解。譬之「歸妹，女之終也」一語，苟不知八宮次序，終於雷澤歸妹，則其義將不解矣！

The sequence arranged in the "Xugua Zhuan" originates from the generative and transformative relationships of the Later Heaven Trigrams, belonging to the "use" aspect. The order of the eight palaces' own palace sequences originates from the generative and transformative relationships of the Earlier Heaven Trigrams, belonging to the "essence" aspect. "Essence" is associated with stillness, symbolized by the Trigram of Earth (Kun), so when the eight palaces reach the hexagram "Guimei," it signifies the end of the Earth path. The Later Heaven Trigrams take Yang as their active principle, symbolizing Heaven (Qian), so when the "Zhouyi" reaches "Weiji," it signifies the end of the Heaven path. These two approaches differ in their beginning and end, thus their uses are different. One must consult the "Yi Zhuan" to understand the reasons behind these differences. Moreover, the "Lianshan Yi" of the Xia Dynasty began with the Trigram of Mountain (Gen), while the "Guicang Yi" of the Yin Dynasty began with the Trigram of Earth (Kun). The sequence of the sixty-four hexagrams differs in each case, and even the square diagram, circular diagram, and the sequence of hexagrams aligned with the seasons are not consistent. All hexagrams generated from the Trigrams of Heaven and Earth have fixed sequences, but the text of the Classic only lists the one determined by King Wen. Without consulting the explanatory texts, other Yi diagrams cannot be understood. This is not merely an incompleteness in usage. The statements in the text of the Classic often follow the old expressions from the "Lianshan" and "Guicang." Their meanings are thus difficult to grasp. For example, the statement "Guimei signifies the end of a woman's life" would make no sense without knowing that the sequence of the eight palaces ends with the hexagram "Guimei" (Thunder and Marsh).

以經文次序，明明終於末濟，與歸妹何涉？是則女終之義，實非取於今易者也。況一曰男，一曰女，對舉而言，即分屬乾坤二者。乾道成男，坤道成女，固有明解；而未濟之男窮，即指乾氣之盡；歸妹之女終，即指坤氣之盡。然序卦終以未濟，可見本乾道之始終也；本宮則本坤道，斯為不同。而不同者正其同也，由於先後天也，合之則同，分之則異，未有離體用為之者，故異仍同。

According to the order of the text, it clearly ends with the hexagram "Wei Ji," so how is it related to "Gui Mei"? This shows that the meaning of "female's end" is not derived from the present version of the Zhou Yi. Moreover, the Zang Guà Zhuan mentions "male" in one sentence and "female" in another, contrasting them, which clearly assigns them to the hexagrams Qian and Kun respectively. The Xi Ci Zhuan says, "The way of Qian produces the male, and the way of Kun produces the female," which is clear: the "male's end" in Wei Ji refers to the end of the Qian energy, while the "female's end" in Gui Mei refers to the end of the Kun energy. The Xu Guà ends with Wei Ji, indicating that it follows the beginning and end of the Qian way; the eight palaces, however, follow the Kun way, which is the difference between them. Yet this difference is precisely their similarity, because they originate from the Earlier Heaven and Later Heaven respectively: when viewed together, they are one matter, but when viewed separately, they become two. There has never been a system that separates "body" and "function" to establish another set, so although they appear different, they are still based on the same principle.

人之既生，神形同具，性情兩全，若分則死矣。然性情自別，神形亦殊，又不可混為一談。是以言易必廣徵其異，以歸於同。易之序卦為主，餘皆為參互之用；以餘合一，則異皆同，故易經但取其一，夫子亦仍之。而恐人之忘其餘也，則備述於傳，以為習易之助，俾讀者得會通之，而勿失其宗也。故傳者，習易所必先讀者也。

When a person is born, both spirit and body are present, and nature and emotion are both complete. If they are separated, the person dies. However, "nature" and "emotion" are fundamentally different, and "spirit" and "body" are also distinct and cannot be confused. Therefore, in explaining the Book of Changes, one must widely examine the differences among various schools of thought and finally return to a single fundamental principle. The sequence of hexagrams in the Book of Changes is mainly based on the order established in the "Sequence of Hexagrams," while other arrangements are used as references and cross-verifications. By incorporating all other arrangements into this one, all differences are unified. Therefore, the Book of Changes selects only one arrangement, and Confucius, when compiling the classic, continued to use it. However, he was also concerned that later generations might forget the other arrangements, so he recorded them all in the "Commentaries on the Changes" as supplementary material to help learners integrate and understand the principles of the Book of Changes, so they do not lose the main purpose of the study of the Changes. Therefore, the "Commentaries on the Changes" are essential for those who wish to study the Book of Changes.