Exploring the Origins of the I Ching: The Evolution of the Eight Trigrams and the Spiritual Core of Chinese Civilization

Amidst the brilliant galaxy of Chinese classics, the I Ching (also known as the Book of Changes) has always occupied a unique core position. This ancient text, often referred to as the Zhou Yi, is not only one of the oldest known classics in China but also revered by scholars of all dynasties as "the paramount classic and the source of fundamental principles" due to its profound ideological depth and cultural breadth spanning millennia. It is not the solitary work of a single sage in one era, but a crystallization of wisdom forged collectively by ancient ancestors and scholars of the pre-Qin period (c. 2100–221 BCE). Its evolution from primitive observations of nature to a mature philosophical system is itself a condensed history of early Chinese civilization.

I. The Origin of the Eight Trigrams: Primitive Decoding of Cosmic Order by Ancient Ancestors

As the symbolic foundation of the I Ching, the Eight Trigrams trace their roots to the late Neolithic Age (c. 3000 BCE). At that time, humans had not yet developed a systematic writing system, but they had already begun to explore the connection between nature and themselves with a sense of awe. Legend has it that Fu Xi, a cultural ancestor of ancient China, "observed celestial phenomena to determine the seasons" on the banks of the Yellow River—he gazed up at the sky to record the movement of the sun, moon, and stars, and looked down at the earth to identify the trends of mountains, rivers, and the withering and flourishing of plants. From the patterns of seasonal cycles and day-night alternations, he extracted eight fundamental forces governing the universe.

Thus, Fu Xi used the symbol "—" (yangyao, representing active, vigorous energy) and "--" (yinyao, representing receptive, gentle energy) to form the Eight Trigrams: Qian (Heaven), Kun (Earth), Zhen (Thunder), Xun (Wind), Kan (Water), Li (Fire), Gen (Mountain), and Dui (Lake). This set of minimalist linear symbols was not only a concrete summary of natural phenomena by ancient ancestors but also implied the primitive philosophical thought of "the unity of man and nature." They believed that all changes in the world could be explained through the combination and interpretation of the Eight Trigrams—laying the ideological groundwork for the subsequent development of the I Ching.

II. Passing the Torch: The Transformation from Yi Texts of the Three Dynasties to a Philosophical Classic

The symbolic system of the Eight Trigrams was not static but continuously enriched during the transitions of the Xia, Shang, and Zhou dynasties, forming a clear evolutionary trajectory:

• **Xia Dynasty (c. 2070–1600 BCE)😗*Lianshan Yi

  As the earliest known Yi text, the Lianshan Yi took the Gen Trigram (symbolizing mountains) as its starting point. The Xia people rose in the mountainous regions along the Yellow River and held a deep reverence for mountains. The sequence of trigrams in this text not only reflected the Xia people’s dependence on mountains and geography but also recorded divination experiences related to agriculture and ritual ceremonies—serving as a practical tool to guide the production and daily life of ancient people.

• **Shang Dynasty (c. 1600–1046 BCE)😗*Guicang Yi

  After the Shang people replaced the Xia Dynasty, they developed the Yi text into the Guicang Yi, which began with the Kun Trigram (symbolizing earth). The Shang people valued agricultural cultivation and ancestral worship, and their society still retained vestiges of matriarchal culture. The central position of Kun not only embodied gratitude for the earth’s nurturing of all things but also implied respect for female ancestors. Building on the Lianshan Yi, its content focused more on interpreting good and bad fortune, deeply integrating with the Shang Dynasty’s advanced oracle bone divination culture.

• **Zhou Dynasty (c. 1046–256 BCE): Maturity of the **Zhou Yi

  In the early Western Zhou Dynasty, King Wen of Zhou (Ji Chang) was imprisoned in Youli by King Zhou of Shang. During his imprisonment, he built on the Yi texts of the Xia and Shang dynasties, combining the Eight Trigrams in pairs to form 64 hexagrams, each accompanied by a brief "hexagram statement" (gua ci) that endowed the symbolic system with richer semantic connotations. Later, the Duke of Zhou (Dan, King Wen’s son) composed the Tuanzhuan (Commentary on the Main Ideas of Hexagrams) and Xiangzhuan (Commentary on the Images of Hexagrams) to interpret the principles of the hexagrams, integrating Yi philosophy with the ritual system and ethical norms of the Zhou Dynasty.

By the late Spring and Autumn Period (c. 5th century BCE), Confucius (Kong Qiu) was so obsessed with the I Ching in his later years that he "wore out the leather straps binding the bamboo slips three times" (a reference to his frequent reading, as ancient texts were written on bamboo slips tied with leather straps). Together with his disciples, he supplemented the original text with ten chapters known as the "Ten Wings" (Shi Yi), including the Wenyan (Commentary on the Qian and Kun Hexagrams), Xici (Commentary on the Appended Phrases), and Shuogua (Commentary on the Trigrams). The "Ten Wings"—as if giving wings to the I Ching—completely elevated it from a divination text to a philosophical classic. By interpreting the principles of "yin-yang dialectics" and "the balance of firmness and gentleness," it endowed the text with depth in cosmology, outlook on life, and values, making it an important source of Confucian thought.

III. The Foundation of Cultural Heritage: A Cross-Millennial Cultural Influence

The value of the I Ching has never been confined to the text itself; instead, it has permeated all aspects of Chinese civilization, becoming a spiritual gene that shapes the national way of thinking:

• Ideological Dimension

  Its concepts of "interdependence of yin and yang" and "unity of man and nature" established the core framework of traditional Chinese philosophy. Confucianism derived ethical order from the idea that "the Dao of Qian gives birth to masculinity, and the Dao of Kun gives birth to femininity," emphasizing the "Mean" (zhongyong) and "self-cultivation for governing the state." Taoism drew inspiration from "the Dao generates the One, the One generates the Two," developing the cosmology of "following the Dao of nature." Together, these two schools formed the two pillars of traditional Chinese thought.

• Literature and Art

  The symbols of the Eight Trigrams and the imagery in hexagram statements became important materials for literary creation throughout history. The Tang Dynasty poet Du Fu described the grandeur of Dongting Lake with the line "the cosmos floats day and night" (referencing Qian and Kun, the trigrams of heaven and earth), while the Song Dynasty poet Su Shi used "the images of Kan and Li for refinement" to metaphorically describe life’s changes. In painting and calligraphy, artists drew on the symmetrical beauty and linear rhythm of the Eight Trigrams, pursuing the Eastern aesthetic of "the balance between emptiness and substance."

• Politics and Society

  The concept of "when at an impasse, change; when changed, things will proceed smoothly" served as a theoretical basis for dynastic reforms. The ideals of "constantly striving for self-improvement" (from the Qian Hexagram) and "bearing virtues with breadth" (from the Kun Hexagram) shaped the character of traditional scholars, influencing the logic of governance and the construction of social ethics.

• Scientific Field

  The theory of yin-yang and the five elements in traditional Chinese medicine is directly derived from the dialectical thinking of the I Ching, emphasizing the balance between the human body and nature. Ancient astronomy, calendar-making, and mathematical calculations also often used the Eight Trigrams as a tool for deduction—for example, the design of the armillary sphere by Zhang Heng in the Han Dynasty and Shen Kuo’s interpretation of astronomical phenomena in the Song Dynasty all bear traces of Yi philosophy.

Even in modern times, the dialectical thinking of the I Ching still provides Eastern wisdom for management and psychology, becoming a key entry point for global research on Chinese culture. It has long ceased to be a mere ancient text but has become the "spiritual core" of Chinese civilization—recording ancient ancestors’ understanding of the world and guiding future generations in their eternal pursuit of wisdom.

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The Ancient Transmission Lineage of the I Ching: Analysis of Major Schools and Representative Figures

Since the formation of the I Ching (Book of Changes) and its commentaries, scholars of successive dynasties have never ceased to interpret it. Due to differences in ideological trends and academic methods of each era, distinct traditional schools have gradually taken shape—these schools either focus on symbolic deduction, philosophical elaboration, or integration of various thoughts, collectively constructing the academic landscape of the I Ching’s millennial transmission. From the Xiangshu (Image-Number) School of the Han Dynasty to the Yili (Meaning-Principle) debates of the Wei and Jin Dynasties, and then to the philosophical integration of the Song and Ming Dynasties, the rise of each school is deeply bound to the cultural context of its time. The works and thoughts of representative figures have become key nodes in the transmission of Yi learning.

I. Xiangshu School: Centered on Symbolic Deduction, Connecting Heavenly and Human Principles (Han to Tang Dynasties)

As one of the earliest formed schools of the I Ching, the Xiangshu School’s core proposition is to interpret Yi principles through "Xiang" (trigram images, line images) and "Shu" (yin-yang numbers, heaven-earth numbers). It emphasizes the connection between Yi learning and astronomy, calendar-making, and divination, and became the mainstream official Yi learning in the Han Dynasty, echoing the ideological trend of "interaction between heaven and humans" at that time.

1. Modern Text Yi Learning of the Han Dynasty: Jing Fang and the "Najia Feifu" Theory

• Representative Figure: Jing Fang (Western Han Dynasty, 77–37 BCE), courtesy name Junming, a key figure in Modern Text Yi Learning of the Han Dynasty. Though he died young due to involvement in political struggles, he laid a systematic theoretical foundation for the Xiangshu School.
• Core Propositions: On the basis of traditional Eight Trigrams, he founded the "Najia Theory"—corresponding the Ten Heavenly Stems and Twelve Earthly Branches to the six lines of each trigram, integrating trigram images with astronomy and calendar. He proposed the "Feifu Theory" (Flying and Hidden Lines), holding that each trigram has "flying lines" (manifested lines) and "hidden lines" (latent lines), whose interaction can deduce the good or bad changes of things. He also divided the 64 trigrams into "Eight Palaces", each governing eight trigrams, forming a more precise divination system.
• Influence: Jing Fang’s Xiangshu theory transformed the I Ching from a philosophical classic into a practical divination tool, exerting a profound impact on later divination arts (such as four-column astrology and feng shui). His work Jingshi Yichuan (Jing’s Commentary on the I Ching) remains an important document for studying Han Dynasty Yi learning.

2. Ancient Text Yi Learning of the Han Dynasty: Zheng Xuan and Yi Annotation with "Yaochen"

• Representative Figure: Zheng Xuan (Eastern Han Dynasty, 127–200 CE), courtesy name Kangcheng, a synthesizer of Confucian classics in the Han Dynasty. Though not a pure Xiangshu scholar, he enriched Xiangshu interpretation from the perspective of Ancient Text Confucian classics.
• Core Propositions: He founded the "Yaochen Theory" (Line-Time Correspondence), corresponding the 384 lines of the 64 trigrams to the Twelve Earthly Branches and Twenty-Eight Lunar Mansions, attempting to explain the origin of trigram and line statements from the perspective of astronomical constellations. Meanwhile, he integrated Modern and Ancient Text Yi learning, emphasizing both Xiangshu deduction and Yili connotation. His annotations on the I Ching, absorbing the strengths of various schools, were hailed as "Zheng Learning".
• Influence: Zheng Xuan’s annotated version became the authoritative textbook for Yi learning before the Wei and Jin Dynasties, breaking the opposition between Modern and Ancient Text Yi learning and infusing more academic nature into the Xiangshu School.

3. Transmission of Xiangshu in the Tang Dynasty: Kong Yingda and the Official Zhouyi Zhengyi

• Representative Figure: Kong Yingda (Tang Dynasty, 574–648 CE), courtesy name Chongyuan, a Confucian scholar of the Tang Dynasty who presided over the compilation of Wujing Zhengyi (Correct Meanings of the Five Classics). Among them, Zhouyi Zhengyi (Correct Meanings of the Zhouyi) was the benchmark of official Yi learning in the Tang Dynasty.
• Core Propositions: Based on the Han Dynasty Xiangshu School, he incorporated viewpoints from the Wei-Jin Yili School, advocating that "Xiang is the foundation of Yili"—first clarifying the principles of trigram images, then elaborating on Yili connotations, attempting to reconcile the contradictions between Xiangshu and Yili. His annotated version took Wang Bi’s Zhouyi Zhu (Commentary on the Zhouyi) as the base text but supplemented a great deal of Han Dynasty Xiangshu interpretation, avoiding the emptiness of pure Yili.
• Influence: Zhouyi Zhengyi became the standard textbook for the imperial examination in the Tang Dynasty, enabling the official transmission of the core theories of the Xiangshu School and laying the groundwork for the "integration of Xiang and Yili" in Neo-Confucian Yi learning of the Song Dynasty.

II. Yili School: Centered on Philosophical Elaboration, Separating from Xiangshu Fabrication (Wei-Jin to Song-Ming Dynasties)

Emerging in the Wei and Jin Dynasties, the Yili School opposed the Han Dynasty Xiangshu School’s overemphasis on divination and forced attachment. It advocated interpreting the I Ching through Confucian ethics and Taoist thought, restoring it to a philosophical classic. This school reached its peak in the Song and Ming Dynasties, integrating deeply with Neo-Confucianism and Mind Learning, and became an important carrier of traditional Chinese philosophy.

1. Xuanxue Yi Learning of the Wei-Jin Dynasties: Wang Bi and "Grasping Meaning by Forgetting Images"

• Representative Figure: Wang Bi (Cao Wei of the Three Kingdoms, 226–249 CE), courtesy name Fusi, one of the founders of Wei-Jin Xuanxue (Neo-Taoism). Though he died at the age of 24, he reconstructed the interpretive path of Yi learning with Zhouyi Zhu.
• Core Propositions: He put forward "grasping meaning by forgetting images, and grasping images by forgetting words"—holding that trigram images (Xiang) are tools for expressing Yili (meaning), and language (words) is a tool for describing trigram images. Interpreting the I Ching should penetrate through images and words to reach the essence of Yili, opposing the Han Dynasty scholars’ practice of "being constrained by Xiangshu and losing Yili". He interpreted the I Ching with Taoist thought of "inaction", explaining "Tai Chi" as "nothingness", making Yi learning compatible with Xuanxue.
• Influence: Wang Bi’s Zhouyi Zhu completely reversed the development direction of Yi learning, making the Yili School the mainstream. His "grasping meaning by forgetting images" remains an important methodology for Yi learning interpretation to this day.

2. Neo-Confucian Yi Learning of the Song Dynasty: Cheng Yi and "Interpreting Yi with Confucianism"

• Representative Figure: Cheng Yi (Northern Song Dynasty, 1033–1107 CE), courtesy name Zhengshu, one of the founders of Neo-Confucianism. His work Yichuan Yizhuan (Yichuan’s Commentary on the I Ching) is a classic of the Song Dynasty Yili School.
• Core Propositions: He closely integrated the I Ching with Confucian ethics, advocating that "the Dao of Yi is the Dao of heaven, and the Dao of heaven is the Dao of humans"—holding that the good or bad fortune and regrets in trigram and line statements are essentially the guidance of "heavenly principle" for human affairs. The purpose of studying the I Ching is to "investigate principle and fulfill nature", not to divine good or bad luck. He opposed Wang Bi’s Taoist tendency, emphasizing that "principle" is the core of Yi learning. For example, he corresponding "Qian as firm and vigorous" to the Confucian virtue of "constantly striving for self-improvement", and "Kun as gentle and receptive" to "bearing virtues with breadth".
• Influence: Cheng Yi’s Yi learning returned the Yili School from Xuanxue to Confucian orthodoxy, providing an important philosophical basis for Song-Ming Neo-Confucianism. His method of "investigating principle through affairs" also influenced the academic path of later Confucians.

3. Synthesizer of Song Dynasty Neo-Confucianism: Zhu Xi and Zhouyi Benyi

• Representative Figure: Zhu Xi (Southern Song Dynasty, 1130–1200 CE), courtesy name Yuanhui, a synthesizer of Neo-Confucianism. His Zhouyi Benyi (Original Meaning of the Zhouyi) is one of the most influential Yi learning works in later generations.
• Core Propositions: He reconciled Xiangshu and Yili, holding that "Xiangshu is the foundation of Yili, and Yili is the destination of Xiangshu"—acknowledging the original meaning of the Eight Trigrams symbols (such as the Xiangshu value of Fu Xi’s Innate Eight Trigrams) while emphasizing the need to elaborate their moral connotations through Yili. He divided the I Ching into "Classic" (trigram and line statements) and "Commentaries" (Ten Wings), advocating reading the "Classic" first to understand Xiangshu, then the "Commentaries" to understand Yili, opposing the extremism of "discussing Yili apart from Xiang" or "discussing Xiang apart from Yili".
• Influence: Zhouyi Benyi became the standard annotated version for the imperial examination in the Ming and Qing Dynasties. His viewpoint of "integrating Xiang and Yili" remains the mainstream Yi learning perspective to this day, and Zhu Xi is regarded as the synthesizer of the Yili School.

4. Mind Learning Yi Learning of the Ming Dynasty: Wang Shouren and "Mind is Yi Principle"

• Representative Figure: Wang Shouren (Ming Dynasty, 1472–1529 CE), courtesy name Bo’an, founder of Mind Learning. His Yi learning thoughts are scattered in Chuanxilu (Record of Instructions for Practical Living) and Wujing Yishuo (Random Notes on the Five Classics). Though he did not leave a specialized Yi annotation, he founded the "Mind Learning Yi School".
• Core Propositions: He put forward "mind is principle, and principle is Yi"—holding that the Yili of the I Ching is not in books but in human’s original mind. "The Eight Trigrams are nothing but the constant Dao of my mind". For example, "the firmness and vigor of Qian" is the "innate knowledge" of the original mind, and "the gentleness and receptivity of Kun" is the "sincerity" of the original mind. He opposed empty discussion of Yili divorced from the original mind, advocating "tempering in affairs" and realizing Yili through practicing innate knowledge.
• Influence: Wang Shouren’s Mind Learning Yi School pulled Yi learning from "external heavenly principle" back to "internal original mind", infusing subjective initiative into the Yili School and playing an important role in promoting ideological emancipation in the mid-to-late Ming Dynasty.

III. Tushu School: Centered on Diagrams, Deducing Cosmic Laws (Song to Yuan Dynasties)

Emerging in the Song Dynasty, the Tushu School is a special school whose core proposition is that the I Ching originated from the "Hetu" (River Diagram) and "Luoshu" (Luo Diagram)—legendary diagrams obtained by Fu Xi from the Yellow River and Luo River. It holds that the Eight Trigrams and 64 trigrams are all derived from these diagrams, focusing on deducing cosmic generation laws through diagrams, and is a new form of the Xiangshu School in the Song Dynasty.

Representative Figure: Shao Yong and the "Innate Eight Trigrams Diagram"

• Shao Yong (Northern Song Dynasty, 1011–1077 CE), courtesy name Yaofu, also known as Mr. Anle, founder of the Tushu School. His work Huangji Jingshi (Cosmic Chronology According to the Imperial Ultimate) constructed a grand cosmological system based on Tushu Yi learning.
• Core Propositions: He proposed the distinction between "Innate Eight Trigrams" and "Acquired Eight Trigrams"—holding that the one created by Fu Xi is the "Innate Eight Trigrams" (ordered with Qian in the south, Kun in the north, Li in the east, Kan in the west), reflecting the inherent yin-yang laws of the universe; the one deduced by King Wen of Zhou is the "Acquired Eight Trigrams" (ordered with Li in the south, Kan in the north, Zhen in the east, Dui in the west), reflecting the human affairs laws of interaction between heaven, earth, and humans. With the "Innate Diagram" as the core, combined with the time unit of "Yuan, Hui, Yun, Shi" (cosmic cycles), he deduced the cyclic process of the universe from generation to destruction, attempting to explain the origin and changes of all things in heaven and earth with Yi principles.
• Influence: Though Shao Yong’s Tushu Yi learning has a certain mysterious color, it added a cosmological dimension to the I Ching. His Innate Eight Trigrams Diagram remains an important diagram in Yi learning and divination arts to this day, exerting an indirect influence on later astronomy and mathematics.

IV. Conclusion: The Vitality of Yi Learning Behind the Diversity of Schools

The evolution of ancient I Ching schools is essentially the continuous inquiry of scholars of different eras into "what is Yi principle": the Xiangshu School focuses on "heavenly laws", attempting to connect heaven and humans through symbols; the Yili School focuses on "human ethics", attempting to guide self-cultivation with Yi principles; the Tushu School focuses on "cosmic generation", attempting to explain the origin of all things through diagrams. These schools are not isolated but promote the development of Yi learning through opposition and integration—for example, Zhu Xi reconciled Xiangshu and Yili, and Wang Shouren integrated Mind Learning into Yili, all reflecting the inclusive nature of Yi learning. Representative figures such as Jing Fang, Wang Bi, Cheng Yi, Zhu Xi, and Shao Yong, though following different academic paths, collectively accomplished one thing: transforming the I Ching from ancient divination symbols into a core classic penetrating traditional Chinese philosophy, ethics, and culture. Their works and thoughts are not only "guideposts" for the transmission of Yi learning but also important keys to understanding the way of thinking in ancient China.

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The Origin and Evolution of I Ching Divination: Mainstream Methods and Their Temporal-Spatial Contexts

The divination tradition of the I Ching (Book of Changes) is as ancient as the text itself, evolving alongside the ideological trends and social needs of different eras. From the solemn rituals using milfoil stalks in the Pre-Qin period to the simplified practices with coins and natural phenomena after the Tang and Song dynasties, the rise and fall of each method bears distinct marks of its time. Below is an analysis of the core connotations of mainstream divination methods from ancient to modern times, paired with their origins and popular periods:

I. Dayan Divination Method: "Orthodox Milfoil Divination" from Pre-Qin to Han Dynasty (c. 10th Century BCE – 3rd Century CE)

As the earliest recorded systematic divination method, the Dayan Divination is first mentioned in Zhouyi·Xici Shang (Appended Remarks I of the I Ching). Its origin can be traced to the early Western Zhou Dynasty, coinciding with the formation of the I Ching’s classics and commentaries, and it served as a core tool for divination and decision-making among the aristocracy in the Pre-Qin period.

Core Operation

Using 50 milfoil stalks (regarded as "sacred objects"), one stalk is first removed to symbolize "Tai Chi" (the Ultimate), leaving 49 stalks for the four-step calculation of "dividing into two, setting aside one, counting by fours, and gathering the remainders":

1. Divide into two: Randomly split the 49 stalks into two piles, representing "the separation of heaven and earth";
2. Set aside one: Take 1 stalk from the right pile and hold it between the fingers, symbolizing "humans standing between heaven and earth";
3. Count by fours: Count each pile in groups of 4, representing "the circulation of the four seasons";
4. Gather the remainders: Combine the remainders from both piles with the set-aside stalk, completing "one transformation (bian)". Repeat the calculation three times (three transformations) to obtain one "yao" (line of a hexagram). A total of 18 transformations generate a complete hexagram of six lines. Good or bad fortune is judged based on the nature of the lines: "old yin" (--×) and "old yang" (—○) are "changing lines" that require reference to the transformed hexagram for interpretation.

Popularity and Decline

It flourished from the Pre-Qin period to the Western Han Dynasty, regarded as the "sacred way" to communicate between heaven and humans, closely linked to ritual culture and political decision-making of the time. After the Eastern Han Dynasty, its complex operations (taking tens of minutes to form a hexagram) and the simplification trend of the Xiangshu School (Image-Number School) led to its gradual replacement by simpler folk methods. However, it has always been regarded as the "foundation of divination" by I Ching researchers, with Zhu Xi reconstructing its process in detail in Zhouyi Benyi (Original Meaning of the I Ching).

II. Lue Divination Method: "Simplified Milfoil Divination" of the Han Dynasty (2nd Century BCE – 3rd Century CE)

The Lue Divination is a simplified version of the Dayan Divination, emerging in the mid-Western Han Dynasty and popular among the folk and grassroots officials during the Western and Eastern Han Dynasties. Its core motivation was to address the "time-consuming and labor-intensive" drawbacks of the Dayan Divination, adapting to the need for quick divination in daily affairs.

Core Characteristics

Existing records are scattered in Han Dynasty texts such as Jiaoshi Yilin (Jiao’s Forest of Changes) and Jingshi Yichuan (Jing’s Commentary on the I Ching). While the complete operation has not been preserved, research suggests its core was simplifying the "three transformations": reducing the number of milfoil stalks (e.g., using 36), merging the "counting by fours" and "gathering remainders" steps, or even replacing complex calculations with "casting milfoil to determine odd or even numbers". Essentially, it retained the tradition of using milfoil as a medium while pursuing efficiency.

Historical Significance

As a transitional form from the Dayan Divination to later simplified methods, it directly influenced the divination system of the Jingfang Xiangshu School. Its idea of "simplifying calculations and emphasizing practicality" laid the groundwork for the subsequent emergence of coin divination.

III. Coin Divination Method: "Folk Mainstream" from Northern and Southern Dynasties to Modern Times (5th Century CE – Present)

The Coin Divination is a monetized alternative to milfoil divination, replacing stalk calculations with coin casting. Originating in the Northern and Southern Dynasties, it gradually replaced milfoil divination as the folk mainstream after the Sui and Tang Dynasties and remains widely used today.

Origin and Finalization

Its prototype was recorded by scholars Huang Qing of the Northern Qi Dynasty and Li Mengxi of the Sui Dynasty. Jia Gongyan of the Tang Dynasty clearly defined its rules in Yili Shu (Commentary on the Book of Rites): "Three tails (reverse side of coins) are called 'heavy coins', corresponding to nine; three heads (obverse side) are called 'interchangeable coins', corresponding to six", marking the finalization of the method. Its rise was directly related to the popularization of coin circulation and the prosperity of folk divination after the Wei and Jin Dynasties. In the Northern Song Dynasty, Huozhu Lin (Forest of Fire Pearls) integrated it with Jingfang’s Najia Theory (Stem-Branching Matching Theory), forming the "Six Yao Najia Divination Method" and laying the foundation for its later development.

Core Operation

The mainstream is the "Three-Coin Divination", preferably using square-holed coins such as Qianlong Tongbao (with the obverse inscribed with characters as "zi" and the reverse as "bei"): Hold three coins in clasped hands, shake them, and cast onto a divination plate six consecutive times to obtain six lines; "Two tails and one head" represent shaoyang (young yang, —), "two heads and one tail" represent shaoyin (young yin, --), "three tails" represent laoyang (old yang, —○), and "three heads" represent laoyin (old yin, --×); Laoyang and laoyin are changing lines, and good or bad fortune is judged by combining the original hexagram, transformed hexagram, and Najia Theory. In the Ming Dynasty, the "Six-Coin Divination" emerged, casting six lines at once to further simplify the process, but it did not replace the three-coin method as the mainstream.

Popularity Context

It developed from the Northern and Southern Dynasties to the Tang Dynasty, flourished during the Song, Yuan, Ming, and Qing Dynasties, and became the preferred divination method for fortune-tellers and ordinary people to predict marriage, livelihood, and other matters. Zhu Xi noted in Zhuzi Yulu (Classified Conversations of Master Zhu) that it "still retains the legacy of the Han people", acknowledging its traditional roots. Despite cultural shocks in modern times, it continues to circulate in folk customs and remains the most familiar form of I Ching divination among the general public.

IV. Plum Blossom Yishu: "Object-Based Hexagram Formation" from Song Dynasty to Present (11th Century CE – Present)

Plum Blossom Yishu (Plum Blossom I Ching) is a "mental Yi" system independent of milfoil stalks and coins. Traditionally attributed to Shao Yong of the Northern Song Dynasty (though actually compiled in the late Ming and early Qing Dynasties under his name), it emerged in the Song Dynasty and became an important parallel divination method among scholars and the folk.

Origin Background

With the prosperity of the Tushu School (Diagram-Text School) of I Ching studies in the Northern Song Dynasty, Shao Yong proposed the theory of "Xiantian Bagua" (Innate Eight Trigrams), providing a philosophical basis for "forming hexagrams from objects". Its core breakthrough was breaking away from fixed media, using any natural phenomena, time, sounds, etc., as the basis for forming hexagrams, adapting to the "divine for everything" needs of the Song Dynasty’s civic society.

Core Operation

Based on the "Xiantian Bagua numbers" (Qian 1, Dui 2, Li 3, Zhen 4, Xun 5, Kan 6, Gen 7, Kun 8), common ways to form hexagrams include:

1. Time-based hexagram formation: The sum of the year, month, and day numbers forms the upper trigram; the sum of the year, month, day, and hour numbers forms the lower trigram; the total sum divided by 6 gives the moving line (e.g., 5 for Chen year + 12 for the 12th month + 17 for the 17th day = 34, divided by 8 leaves a remainder of 2, corresponding to Dui Trigram; adding 9 for Shen hour = 43, divided by 8 leaves a remainder of 3, corresponding to Li Trigram, forming the Zehuo Ge Hexagram);
2. Object-based hexagram formation: Seeing an elderly person corresponds to Qian Trigram, seeing the south corresponds to Li Trigram, combining orientation and movement to form a hexagram;
3. Character-based hexagram formation: Split the strokes of a Chinese character, with the first half forming the upper trigram and the second half forming the lower trigram. The core of interpreting hexagrams is "the generation and restriction of Ti (subject) and Yong (object)"—taking the main trigram as "Ti" (the matter being divined) and the mutual trigram and transformed trigram as "Yong" (influencing factors), judging trends through the five elements’ generation and restriction relationships.

Popularity Characteristics

It has persisted from the Song Dynasty to the present, widely used in feng shui, date selection, marriage compatibility, and even integrated into clinical diagnosis in traditional Chinese medicine during the Ming and Qing Dynasties. Its flexible nature of "no divination without movement, divination based on events" has made it a "dual tool" for scholars’ self-cultivation and folk practical use, remaining one of the mainstream entry methods for I Ching enthusiasts today.

V. The Underlying Logic of Divination Method Evolution

The millennium-long evolution from the Dayan Divination to Plum Blossom Yishu presents three major trends:

1. Simplification of media: From 50 milfoil stalks to three coins, and further to "everything can form a hexagram", reflecting the transformation of divination from a "sacred ritual" to a "daily tool";
2. Theoretical integration: Early methods focused on "the interaction between heaven and humans", later integrating Najia and five elements theories in the Tang Dynasty, and combining with Xiantian Bagua in the Song Dynasty, embodying the cross-influence of I Ching schools;
3. Enhanced subjectivity: From relying on the "divine will" of milfoil to relying on "mental perception" (e.g., the "mental Yi" of Plum Blossom Yishu), implicitly aligning with Wang Shouren’s ideological vein of "mind is principle". Despite their different forms, these methods collectively inherit the core wisdom of the I Ching—"observing changes to perceive opportunities". Whether the solemn calculation of milfoil stalks or the simple casting of coins, they are essentially the thinking practices of ancient people exploring the connection between "heavenly Dao" and "human affairs".

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Core Ideas of the Way of Change

• Change (bian-yi): everything flows.
• Constancy (bu-yi): enduring patterns underlie change.
• Simplicity (jian-yi): address complexity with clear essentials.

Balance, timeliness, and harmony with nature guide wise action, aligning heaven, earth, and human conduct.