Chapter 2: Historical Origins

The principle-and-qi school has no single founding moment. It grew up in accretive layers out of the divination-based house-siting traditions of high antiquity, the professional diviners' arts of the Han dynasty, the discourse on burial-ground qi of the Six Dynasties, and the compass technology of the Tang and Song, and did not differentiate into the pattern of schools we see today until the Ming and Qing. This chapter traces that two-thousand-year thread across eight sections, organized by period. One caveat should be flagged in advance: a defining feature of fengshui's historical sources is that layered accretion and false attribution go hand in hand—doctrines that emerged late invariably trace their ancestry back to early sages, so that the date a text claims for itself is often centuries removed from its actual date of composition. This chapter will build its argument as far as possible on reliable historical sources, and will explicitly flag legend as legend.

2.1 The Pre-Qin Period and the Han Dynasty: The Divination Tradition, the Art of House Charts, and the Cosmic Board

The idea of choosing and siting a dwelling long predates the term "fengshui." The Book of Documents, "Announcement of Shao," records that when the Duke of Zhou built the city of Luoyi, he first "surveyed the site" (xiang zhai) and only afterward divined it; the Book of Songs, in the "Greater Elegantiae" ode "Gong Liu," describes how Lord Liu, upon migrating to Bin, "measured the shadow and climbed the ridge, observed its yin and yang, and inspected the flow of its springs"—measuring the sun's shadow, climbing the ridge, examining the yin-yang orientation, and observing the direction of water flow are nearly the full complement of elements that later siting arts would develop. But house-siting at this stage was a political and practical activity, with no systematic calculation of fortune and misfortune yet attached to it.

A calculative system first appears in the Han dynasty. The bibliographic treatise of the Book of Han records two relevant categories of literature under its section on numerological arts: among the Five-Phases specialists, the Kanyu Jingui in fourteen scrolls—the term "kanyu" itself derives from here, and originally may have concerned the Way of Heaven and Earth or the selection of days; and among the form-method specialists, the Gongzhai Dixing in twenty scrolls, of which Ban Gu says that its practitioners "took the configuration of the Nine Provinces as the basis for laying out city walls and dwellings"—this is regarded as the distant source of the Form School. The distant source of the principle-and-qi school, by contrast, is the art of house charts (tuzhai shu) popular in the Han. Wang Chong criticized it specifically in the "Jieshu" chapter of his Lunheng: "The art of house charts holds that a house has eight techniques, ranked according to the names and numbers of the Six Jia; once the ranking is fixed and the name is established, the modes—gong, shang, and the rest—are distinguished accordingly. A house has an affinity with the Five Tones, and a surname likewise has an affinity with the Five Sounds. If a house does not suit its occupant's surname, and surname and house work against each other, then illness, death, crime, and misfortune will follow." This classified surnames according to the Five Tones (gong, shang, jue, zhi, yu) and matched them against the facing and direction of a house to argue for generation, overcoming, fortune, and misfortune. This system of "the Five Tones and surname-suitability" is worth noting on two counts: first, it already possesses the complete structure of the principle-and-qi school—assigning attributes to person and house through a symbolic system (the Five Tones), and deriving fortune and misfortune through rules of generation and overcoming; second, it incorporates "the person" as a variable in judging a house's fortune, which is exactly the logic that the Eight Mansions school would apply, over a thousand years later, in "matching the life-gua to the house." Wang Chong's critique also opened the way for later literati criticism of fengshui.

A parallel thread from the same period is the cosmic board (shipan). The cosmic board was a divination instrument common among Han-dynasty numerologists, formed by superimposing a round plate symbolizing Heaven (the heaven-plate) onto a square plate symbolizing Earth (the earth-plate); the plates were inscribed with the Northern Dipper, the twenty-eight lunar lodges, the stems and branches, and the trigrams, and used for the liuren, dunjia, and taiyi methods of divination. Physical cosmic boards excavated from Han-dynasty tombs, such as that of the Marquis of Ruyin at Shuanggudui in Fuyang, Anhui, let us confirm with certainty that the operative paradigm of marking directions with the stems, branches, and trigrams, and simulating the circulation of Heaven-and-Earth's qi with a rotating plate, had already matured by the Western Han. The cosmic board is the direct ancestor of the compass—the inner-plate/outer-plate structure and the Twenty-Four-Mountain division of later compasses can both be traced to prototypes on the cosmic board. One might say that the "hardware" tradition of the principle-and-qi school was already laid down as early as the Han.

2.2 The Wei, Jin, Sui, and Tang Dynasties: Guo Pu's Zangshu and the Founding of the Discourse on Qi

Around the Wei-Jin transition, discourse on the fortune and misfortune of burial grounds flourished greatly. The Book of Jin, "Biography of Guo Pu," records that Guo Pu (276–324) was expert in divination and siting, and stories of his choosing burial sites for others were widely retold in his time. The Zangshu (Book of Burial), traditionally attributed to Guo Pu, is the single most important theoretical text in the history of fengshui: it was the first to establish "qi" as the central concept of burial art—"in burial, one rides upon the living qi"—and the first to give the classic definition of the term "fengshui" (wind and water) itself: "qi, riding upon the wind, disperses; bounded by water, it comes to a halt. The ancients gathered it so that it would not disperse, and moved it so that it would come to a halt—hence they called it fengshui." The Zangshu also put forward propositions such as "shelter the wind and obtain the water" and "when the form halts, the qi accumulates," laying down the shared foundational discourse on "qi" upon which every subsequent school of fengshui, whether of the Form or the Principle-and-Qi tradition, would draw.

It must be noted, however, that the authorship of the Zangshu is academically doubtful. The book does not appear in the bibliographic treatises of the Book of Sui or the Old Book of Tang, and is first recorded only in the Song dynasty, its text having been edited and pared down by Song scholars (traditionally said to be Cai Yuanding) into an inner, outer, and miscellaneous set of three chapters; the Complete Catalogue of the Siku Quanshu itself suspects it to be a later work falsely attributed. In other words, "Guo Pu wrote the Zangshu" is better understood as a retrospective adoption by the fengshui tradition rather than as historical fact. But regardless of who its actual author was, the Zangshu's discourse on "qi" supplied the fundamental premise for the principle-and-qi school—if fortune and misfortune hinge on formless qi, then a method for calculating that formless qi becomes necessary, and this is precisely what gave the learning of principle-and-qi its reason to exist.

Around the Sui-Tang transition, both official and popular siting arts were highly active. Xiao Ji of the Sui compiled the Wuxing Dayi, which systematically organized the shared numerological resources of the Five Phases, the stems and branches, na-yin, and the Nine Palaces; most of the symbolic tools later used by the principle-and-qi school can be found already formulated in this book. Under Emperor Taizong of Tang, the Court Erudite Lü Cai was commissioned to correct and edit the books of yin-yang; his prefaces to the Zhaijing (House Classic) and the Zangshu (preserved in his biography in the Old Book of Tang) sharply criticized the Five-Surname house method then in vogue: "As for the shamans of recent generations, they have further added the theory of the Five Surnames... Checked against the classics, there is fundamentally no such doctrine; none of the books of yin-yang contain any such statement either"—which shows both that the art of surname-suitability by the Five Tones had remained the mainstream house method from the Han through the Tang, and that official scholarly criticism never actually halted its spread. The various manuscript copies of house classics preserved among the Dunhuang documents (the ancestral text of today's Yellow Emperor's House Classic belongs to this lineage), which discuss fortune and misfortune in terms of yin and yang dwellings and twenty-four routes, can be seen as an intermediate form in the transition from the Five-Surname house method to the later directional house methods. The Yellow Emperor's House Classic's well-known analogy of the house as a human body—"the house takes its form and configuration as its body, its springs and waters as its blood vessels, its earth as its flesh and skin, its plants and trees as its hair, its rooms as its clothing, and its gate as its cap and sash"—has been repeated ever since; and its "twenty-four routes," which arrange the stems, branches, and trigrams around the house and discuss what is auspicious or inauspicious for building work according to yin and yang, already contain the embryo of the Twenty-Four Mountains—the three-stage leap in directional resolution, from the eight directions to the twenty-four routes to the compass's Twenty-Four Mountains, was completed between the Tang and Song. At the institutional level, the Tang dynasty's Bureau of the Grand Diviner was charged with divination and siting, and popular burial masters (then called "yin-yang men" or "dili men") had already become a recognized trade; both Liu Zongyuan and Han Yu discuss and debate the fortune and misfortune of burial sites in their writings—by the Tang dynasty, both the knowledge base and the market for the principle-and-qi school had already taken shape in outline.

2.3 The Late Tang and Five Dynasties: The Historical Facts and Legends of Yang Yunsong and His Books

In the collective memory of the fengshui trade, Yang Yunsong is the patriarch second only to Guo Pu, and nearly every school within the principle-and-qi tradition traces its own doctrine back to his name. According to legend, Yang Yunsong's given name was Yi, his courtesy name Shumao, and his sobriquet Jiupin ("Rescuer of the Poor"); he was a native of Douzhou, rose under Emperor Xizong of Tang to the rank of Grand Master of Golden Purple Splendor, and was charged with astronomical and geomantic affairs at the Spirit Terrace. When Huang Chao sacked Chang'an, he fled south carrying the secret geomantic texts stored in the palace, cut his hair and entered the Kunlun Mountains, and later lived in seclusion at Qianzhou (present-day Ganzhou, Jiangxi), practicing the art of siting among the common people. He is said to have transmitted his learning to disciples such as Zeng Wenchan, Liao Yu (Liao Jinjing), and Liu Jiangdong; the Zeng and Liao clans of Sanliao village in Xingguo, Ganzhou, still claim direct descent from him today.

The above is legend. On the level of historical fact, the situation is this: neither of the two Tang histories contains a biography of Yang Yunsong, and no such office as "charged with astronomical and geomantic affairs at the Spirit Terrace" can be verified in Tang institutional records; the earliest records concerning him appear only in Song-dynasty compilations and local gazetteers, and the various accounts contradict one another. An enormous number of works are falsely attributed to Yang Yunsong—the Canglong Jing, the Yilong Jing, the Zangfa Daozhang, the Qingnang Aoyu, the Tianyu Jing, the Ducian Baozhao Jing, the Yuchi Jing, and others—and their styles and systems differ so greatly that they plainly cannot be the work of one person at one time. The Complete Catalogue of the Siku Quanshu, in its abstract for the Canglong Jing, already remarks that it "has been transmitted in the world as originating with Yang Yunsong, yet there is no firm evidence for this."

For the purposes of this article, the significance of Yang Yunsong lies less in his being a historical figure than in his function as a bibliographic coordinate: the two clusters of texts attributed to him correspond precisely to fengshui's two great traditions—the Canglong Jing and Yilong Jing, devoted entirely to mountain-dragon form, became the canonical scriptures of the Form School; the Qingnang Aoyu, Tianyu Jing, and Ducian Baozhao Jing, filled page after page with cryptic trigram doctrine, became the canonical scriptures of the principle-and-qi school (especially the Xuankong lineage). The name "Master Yang" thereby became a banner for both schools at once, and planted the seed for the later contest among the various schools over who held the right to interpret "the authentic transmission of Master Yang."

The living vessel of the Yang Yunsong tradition is Sanliao village in Xingguo, Ganzhou. Generation after generation of the Zeng and Liao clans in the village have practiced kanyu; their genealogies claim descent from Zeng Wenchan and Liao Yu, and tradition holds that during the Yongle reign of the Ming, Zeng Congzheng, Liao Junqing, and others were summoned to take part in siting the imperial mausoleum (Chang Ling, the first and chief tomb of the Ming Thirteen Tombs)—the degree to which local records and court archives corroborate this is still debated among scholars, but it is a well-documented social fact that the geomancers of Sanliao took on siting commissions for both officialdom and the public throughout the Ming and Qing dynasties, and that their footprints extended across the southern provinces. Today, Sanliao develops cultural tourism as "the foremost village of kanyu culture," where the Shrine to Master Yang, the ancestral shrines of the Zeng and Liao clans, and the orally transmitted formulas of the various branches all coexist, making it a living specimen for observing the institution of fengshui master-to-disciple transmission: the clan genealogy functions as a certificate of lineage, the ancestral shrine as the trade's guild hall, and the narrative of "personal transmission from Master Yang" is here not a matter of textual scholarship but a professional identity and livelihood structure that continues into the present. The history of the principle-and-qi school was never written in books alone—it is also written into villages such as this one.

2.4 The Divide between the Two Lineages: The Jiangxi Method and the Fujian Method

The Song dynasty is the period in which fengshui's two great traditions became clearly distinct. Although the theory of the two lineages from Wang Yi's Qingyan Conglu, cited above, was written in the early Ming, the configuration it describes had already taken shape in the Song:

The Jiangxi method takes the lineage of Yang Yunsong and Zeng Wenchan as its source, with its center of activity in Ganzhou; it "attends solely to the mutual configuration of dragon, lair, sand, and water, and does not concern itself with anything beyond that"—that is, it is centered on form. The Jiangxi lineage produced generation after generation of talented practitioners and a rich body of writing; both Lai Wenjun of the Song and the Xu brothers of the Ming belong to this great branch.

The Fujian method (the ancestral-temple method) "has origins that reach very far back, and only flourished widely once Wang Ji appeared in the Song"; its distinguishing feature is that it "relies solely on the Eight Trigrams and Five Stars to fix the principle of generation and overcoming"—a purely star-and-trigram calculative practice, and thus a paradigm case of the learning of principle-and-qi. Wang Ji is the patriarch of the Fujian lineage as recorded in the sources, but very little of the early literature of the Fujian lineage survives, so its concrete operative system can no longer be reconstructed in detail. The commonly accepted view in later times is that doctrines such as Eight Mansions, which judge fortune and misfortune by matching trigram cases, descend in an unbroken line from the Fujian lineage.

Behind the divide between the two lineages, one should also recognize the intellectual soil of the Song dynasty. First, there is the rise of the study of diagrams within Yijing scholarship: the River Chart and Luo Writing, and the diagrams of the Earlier Heaven and Later Heaven trigrams, were transmitted through the lineage of Chen Tuan, elaborated by Shao Yong, and given fixed canonical form by Zhu Xi in his Zhouyi Benyi—their canonization was completed precisely in the Song dynasty. The diagrammatic tools on which the principle-and-qi school depends for its operation thus received the endorsement of orthodox Yijing scholarship in this very period, and "discussing dili through the principles of the trigrams" thereby gained scholarly respectability. Second, there is the deep involvement of the scholar-official class: records of siting and burial selection are scattered throughout Song-dynasty note-form writings (biji); accounts of eminent officials and great Confucians choosing sites for their own parents, reburying their dead, and debating the doctrines of yin-yang are innumerable, and Cai Yuanding (a friend and disciple of Zhu Xi) wrote the Fawei Lun on form—the boundary between Confucian scholars and technical practitioners was far more blurred than later generations tend to imagine. The technical maturation of principle-and-qi learning in the Song dynasty was the product of the confluence of three forces—the compass, the study of diagrams, and the participation of the literati class—so that from the very outset it was never a purely popular technical craft, but a hybrid of elite scholarship and popular practice.

It is worth emphasizing that "Jiangxi mastering form, Fujian mastering principle-and-qi" describes the general tendency of each lineage, not an absolute division. The Jiangxi lineage likewise developed a fully articulated body of principle-and-qi learning—the deep-rooted tradition of Sanhe water methods in southern Jiangxi, and the celestial-star trigram cases within the Sanliao transmission, both show that tools of principle-and-qi were never absent even within the Form School's own home base. The divide between the two lineages is a divide of emphasis, not a divide of presence or absence.

2.5 The Song and Yuan Dynasties: Lai Wenjun's Cuiguan Pian, the Maturation of the Compass, and the Technicalization of Principle-and-Qi

The Song dynasty made two decisive contributions to the principle-and-qi school: the maturation of compass (needle-plate) technology, and the appearance of celestial-star principle-and-qi works represented by the Cuiguan Pian.

The compass. The earliest clear record of the compass being used in kanyu appears in the Yingyuan Zonglu (1041), compiled by imperial order under Emperor Renzong of the Northern Song by Wang Zhu and others: in discussing the fixing of a burial site's orientation, it states that "one should take the needle at Bing-Wu"—meaning that the magnetic needle does not point due south (wu), but deviates toward a point between Bing and Wu, and so the needle should be set between Bing and Wu to correct for this. This is not only the earliest textual record of magnetic-needle use in kanyu, but also one of the earliest clear records of magnetic declination in the history of world science and technology, predating Europe's discovery of the phenomenon by roughly four hundred years. A little later, Shen Kuo's Dream Pool Essays records that when practitioners magnetized a needle by rubbing it with a lodestone, it "could point south, yet always deviated slightly to the east, and was never exactly due south," and records four methods of mounting the needle—floating on water, balanced on a fingernail, balanced on the rim of a bowl, and suspended by a thread. A Southern Song note-form work (traditionally attributed to Zeng Sanyi's Yinhua Lu) already states plainly that the kanyu masters' "earth snail" (di luo, i.e., the compass) "sometimes uses the true zi-wu needle, and sometimes uses the seam needle between zi-wu and bing-ren"—the dual-needle system, combining the true needle and the seam needle, had already become fixed practice by the Southern Song. The maturation of the compass meant that the precision of directional measurement leapt from "the eight directions" to "the Twenty-Four Mountains" and finer subdivisions still, establishing the technical threshold on which the principle-and-qi school would depend for its operation. Chapter Four will discuss the compass in dedicated detail.

The Cuiguan Pian. Traditionally attributed to Lai Wenjun of the Song. Lai Wenjun was known to the world as Lai Buyi; tradition holds he was a native of Chuzhou, once served as an official in Jianyang, then abandoned office to wander and practice siting among the people—a patriarch whom popular legend ranks alongside Yang Jiupin. The Cuiguan Pian, written in mnemonic verse, discusses the dragon, the lair, the sand, and the water; its most distinctive feature is combining celestial stars (matching the Twenty-Four Mountains with star names such as Tianhuang, Tianshi, Yangxuan, and Yinshu) with directional Five-Phases theory, to argue which dragon matched with which facing could "hasten office" (bring rapid success in the examinations and official promotion). This work is included in the numerological-arts category of the Siku Quanshu, whose abstract describes its "wording and intent as obscure and profound." In technical history, the Cuiguan Pian represents the maturation of principle-and-qi learning as it deepened from the coarse level of the trigram-palaces down to the level of the Twenty-Four Mountains; later practitioners generally attribute the ren-pan (human-plate) sand-adjusting method found on later compasses to Master Lai's invention (though this claim, too, lacks firm evidence—the human-plate is for this reason also known as the "Lai plate").

Yuan-dynasty sources are comparatively sparse, but two points are worth recording: first, Liu Bingzhong (a powerful minister of the early Yuan, expert in the arts of yin-yang and numerology) became a target of later false attribution—the programmatic text of the Ming-Qing Sanhe school, the Yuchi Jing, is itself attributed to Liu Bingzhong; second, the various elements of principle-and-qi (double-mountain Five Phases, the Twelve Stages of Life water method, na-jia gua-flipping) continued to be integrated in popular practice across the Yuan-Ming transition, laying the groundwork for the systematization of the Ming and Qing.

2.6 The Ming Dynasty: Household Encyclopedias, the Yangzhai Shishu, and the Prehistory of Xuankong

The Ming dynasty is the period in which fengshui became thoroughly popularized and print-based. Knowledge of house- and grave-siting moved out of secret master-to-disciple transmission and into commercially printed books, embedded within household encyclopedias and craftsmen's manuals: the Lu Ban Jing (in the Lu Ban Yingzao Zhengshi tradition) combined judgments of a house's fortune and misfortune with construction dimensions and groundbreaking ritual protocols for craftsmen's daily use; various almanacs (tongshu) turned directional deities and the fortune and misfortune of years and months into consultable tables. During the Wanli reign, Wang Junrong compiled the Yangzhai Shishu (Ten Books on Yang Dwellings), gathering ten categories including the exterior form of the house, the interior form of the house, the Great Roaming Years, the Nine Stars Piercing the Palaces, and date selection—a summa of Ming-dynasty yang-dwelling doctrine. It is worth noting that the "Great Roaming Years" section within it is already a mature form of the Eight Mansions method, showing that the Eight Mansions system had already taken fixed, popular form by at least the mid-to-late Ming (its traditional attribution to the Tang monk Yixing cannot be verified). During the Jiajing reign, the brothers Xu Shanji and Xu Shanshu wrote the Dili Renzi Xuzhi; though centered on form, it draws broadly on multiple schools and cites its sources, making it the best available window onto the map of fengshui knowledge in the Ming.

The legend of the Xuankong lineage also begins in the Ming: practitioners traditionally hold that at the Yuan-Ming transition there was a certain Mujiang Shi (Chan Master Mujiang), expert in Xuankong learning, who transmitted it to Leng Qian and others, who in turn transmitted it down to Wujizi at the end of the Ming—this genealogy of "Xuankong prehistory" comes entirely from retrospective accounts by Qing-dynasty Xuankong masters and has no documentary support, but it reflects one underlying fact: doctrines built on the framework of the Three Cycles and Nine Periods and the flying distribution of the Luo Writing were already brewing in the Jiangnan region by the late Ming, awaiting only a great synthesizer to appear.

One further point is worth noting: in both the Ming and Qing, the Directorate of Astronomy maintained a Bureau of the Water Clock, whose duties included siting fengshui for imperial construction projects and mausolea. The official system of yin-yang instruction (with yin-yang instructors appointed at the prefectural, subprefectural, and county levels) also gave fengshui practitioners a quasi-official status. The social foundation of principle-and-qi learning reached an unprecedented breadth in the Ming dynasty. The peak of official application also arrived in the Ming: when the Yongle Emperor built Beijing and had the Tianshou Mountain mausoleum complex (the Ming Thirteen Tombs) sited by divination, he summoned geomancers from Jiangxi to take part in the site survey (the record of the Zeng and Liao geomancers of Sanliao being summoned, discussed in Section 2.3, belongs to this event); afterward, the siting of imperial mausolea and princely tombs throughout the Ming and Qing left behind whole volumes of kanyu memorials and illustrated archival documents. This body of official archives, with its precisely dated entries and its genuinely identifiable participants, constitutes the most solid layer of historical source material for studying the actual practice of principle-and-qi—its value far exceeds that of the falsely attributed classics, and dedicated compilation and study of it has emerged in recent years.

2.7 The Qing Dynasty: Jiang Daihong's Dili Bianzheng and the Splintering of the Xuankong Schools

Jiang Daihong of the early Qing (given name Ke, courtesy name Pingjie, known by his sobriquet Daihong, a native of Huating in Jiangsu, a Ming-dynasty licentiate who declined to serve under the Qing) is the single most influential and most controversial figure in the history of the principle-and-qi school. By his own account, he studied every school of dili in his early years without any of them proving effective, until he received the authentic secret of Xuankong from Wujizi, and only after "ten years did he finally attain full mastery of the transmission." During the Kangxi reign, he compiled and annotated the Dili Bianzheng: he selected five texts as "scripture"—the Qingnang Jing, the Qingnang Xu, the Qingnang Aoyu, the Tianyu Jing, and the Ducian Baozhao Jing—annotating them passage by passage, and appended an essay, "Exposing the Fallacies of the Pingsha Yuchi Jing," fiercely attacking the Sanhe water methods then in vogue (represented by the Yuchi Jing) as "a false method that deceives the world."

The historical effect of the Dili Bianzheng was twofold. On one hand, through its forceful posture of critique, it reshaped the canonical genealogy of the principle-and-qi school—for the three centuries that followed, the theoretical contest among the various schools was fought almost entirely over the right to interpret these five scriptures as Jiang had fixed them. On the other hand, Jiang Daihong himself firmly held to the secret-transmission principle that "the mechanism of Heaven must not be leaked," and his commentary deliberately concealed core operative content such as the star-shifting formula (what is called "hidden within the text"), so that the Dili Bianzheng became an extraordinary book that "anyone can read, yet no one can put to use." Later students who sought the formula in vain had no choice but to work it out for themselves by conjecture, and so commentaries and sub-commentaries proliferated and divergent readings multiplied. In the mid-to-late Qing, the Xuankong masters who claimed to carry on Jiang's learning splintered into a number of branches, later summarized by Shen Zhurong as the Six Great Xuankong Schools: the Wuchang school (Zhang Zhongshan of Wuxi), the Dian-nan school (Fan Yibin of Yunnan), the Suzhou school (Zhu Xiaohe), the Shangyu school (Duanmu Guohu), the Xiang-Chu school (Yin Yishao), and the Guangdong school (Cai Minshan)—each of the six schools had its own body of writing and its own version of the star-shifting method, and each denounced the others as false. To name a few of their works: Fan Yibin of the Dian-nan school annotated the Qiankun Faqiao; Zhang Zhongshan of the Wuchang school won great renown across Jiangnan for the accuracy of his house judgments; Zhu Xiaohe of the Suzhou school wrote the Dili Bianzheng Bu; Duanmu Guohu of the Shangyu school was also a noted classical scholar (a metropolitan graduate of the Daoguang reign and author of the Zhouyi Zhi); Yin Yishao of the Xiang-Chu school compiled the Sibi Quanshu; and Cai Minshan of the Guangdong school and his son wrote the Bianzheng Qiuzhen—from Yunnan to Guangdong, from candidates for the civil examinations to professional geomancers, one can see from this how widely, and through how many different kinds of carriers, Jiang's learning spread during the Qianlong, Jiaqing, Daoguang, and Xianfeng reigns. Of the six schools, Zhang Zhongshan's Wuchang school enjoyed the greatest renown for the accuracy of its judgments, and his Dili Bianzheng Zhijie and Yinyang Erzhai Luyan became the fuse for the next chapter of this history.

At the same time, the Sanhe school, which Jiang had attacked, did not decline—on the contrary, it reached its own peak of popularization in the mid-Qing: during the Qianlong reign, Zhao Jiufeng (given name Yucai) wrote the Dili Wujue, organizing dragon, lair, sand, water, facing, the Four Great Water Bureaus, and the Twelve Stages of Life water method into an extremely accessible textbook, which spread widely across the country and became the most broadly used popular fengshui manual since the Qing dynasty; his Yangzhai Sanyao matched the "three essentials" of gate, master bedroom, and stove with the Eight Mansions' Roaming Years, and likewise circulated extremely widely. The Eight Mansions lineage was also canonized during the Qianlong reign, when the Daoist Ruoguan compiled the Bazhai Mingjing (attributed to Yang Yunsong). One might say that the map of schools within the principle-and-qi tradition as we see it today—Eight Mansions, Sanhe, Xuankong, and their various offshoots—had all fallen into place by the mid-Qing.

2.8 The Late Qing and Republican Era: Shen Zhurong and the Going-Public of Xuankong Learning, and the Fixing of the School Landscape

Xuankong learning's transformation from a secret art into a widely taught body of knowledge is tied to the late-Qing native of Qiantang, Shen Zhurong (given name Shaoxun, 1849–1906). Shen had sought the secret of Xuankong for decades in vain; during the Guangxu reign, he and his brother-in-law Hu Bo'an made a special trip to Wuxi, and at great expense persuaded Zhang Zhongshan's descendants to let them view the family's secret manuscript, the Yinyang Erzhai Luyan, though not to copy it; the two men spent a whole night committing it to memory and forcibly transcribing it before returning home. On this basis, Shen Zhurong worked backward from the house judgments to reconstruct Zhang's star-shifting method, cross-referenced it against the principles of the Yijing, and arrived at the formula for laying out the flying-star chart; in his later years he wrote extensively and took on students, no longer keeping the method secret. After his death, his son Shen Zumian (Diemin) and his disciples Wang Zexian, Shen Tingchan, and others compiled his surviving manuscripts and published the Shenshi Xuankong Xue (Master Shen's Study of Xuankong) in the 1920s and 1930s, laying out the star-shifting formula, the methods of casting the chart and determining star-shifts, and case records of house judgments, holding nothing back. With the publication of this book, Xuankong Flying Star leapt at a stroke from a secret transmission confined to six schools into an openly learnable body of knowledge, and in the process became the most influential principle-and-qi school of the twentieth century—today, when Hong Kong, Taiwan, and overseas Chinese communities speak of "Xuankong fengshui," nine times out of ten they mean the Flying Star method of the Shen lineage.

Republican-era Shanghai was the center of transmission and competition for principle-and-qi doctrine: Tan Yangwu studied the Wuchang lineage's Flying Star method in his early years from a relative by marriage of the Zhang family, published books on it, and later claimed to have received a separate authentic transmission (said to be from the Daoist master Li Qianxu), publicly declaring that he was abandoning his earlier Flying Star doctrine in favor of a newly proposed "Xuankong Liu Fa" (Six Methods of Xuankong)—a declaration that caused quite a stir at the time; You Xiyin (who later became a monk under the name Yanben) and others recorded large numbers of house-judgment cases from Shanghai in works such as the Zhaiyun Xin'an, pioneering the genre of the "documented case record." In the same period, Jinsuo Yuguan (Guolu Yinyang) circulated among the common people of northern Jiangsu and southern Shandong, while Qiankun Guobao (Longmen Baju) and the various Sanhe methods traveled to Taiwan with Fujianese and Cantonese migrants and flourished there. By this point, the entire landscape of the principle-and-qi schools that the later chapters of this article will survey and assess had taken its final fixed form.

After 1949, the center of gravity for the transmission of principle-and-qi doctrine shifted to Hong Kong and Taiwan. In the decades after the war, the professional fengshui trade flourished in Hong Kong as never before; Xuankong Flying Star, through the writings, newspaper columns, and television appearances of practicing masters, became thoroughly popularized, and books on "the year's fortune" (liunian yuncheng) became an annual publishing phenomenon. Taiwan, meanwhile, saw the Sanhe, Qiankun Guobao, and various Xuankong schools stand side by side, with a well-developed publishing and correspondence-course system for numerological arts. From the 1980s and 1990s onward, these Hong Kong and Taiwan publications flowed back into mainland China, converging with reprinted classical texts and newly written discourses on "architectural culture" to shape the basic landscape of fengshui knowledge in the Chinese-speaking world today. What is particularly worth noting for researchers is the shift in genre that accompanies this history: from the Republican-era documented case record (one house, one judgment, with a verifiable address) to the postwar textbook style (formulas, tables, exercises), and on to the fragmented mnemonic formulas of today's social media—the presentation of the knowledge has moved steadily toward the quick and the condensed, while the structure of "holding something back" from the age of secret transmission has never disappeared; it has simply shifted from "not writing it down" to "writing down only half of it."

Looking back over this two-thousand-year thread, it can be summarized as four key transformations: the Han dynasty completed the prototype of "symbolic calculation" with the doctrine of the Five Tones and surname-suitability; the Six Dynasties established the ontology of "qi" with the Zangshu; the Song dynasty completed a technical upgrade with the compass and pushed resolution down to the level of the Twenty-Four Mountains; and the Ming and Qing completed the formation of distinct schools through the dual tracks of publishing and secret transmission. Once this accretive process is understood, one will no longer ask "which is the original, orthodox lineage of the fengshui principle-and-qi school"—because it never had a single point of origin to begin with.