What schools of feng shui exist and where did they split from: from Guo Pu's Zangshu to Jiangxi terrain forms, Fujian li qi, then San He, San Yuan, Bát Trạch, and Huyền Không

Is feng shui a single unified discipline?

No. Feng shui is a cluster of different technical traditions that share a few foundational concepts (qi, yin and yang, the five phases, the eight trigrams) but disagree on how to measure and how to interpret. According to Encyclopaedia Britannica, entry Feng shui, feng shui is a form of geomancy originating in ancient China, literally "wind and water", built on the assumption that landforms and waterways channel cosmic qi through dwellings and structures. Precisely because the shared foundational assumption is common while the methods of application differ, it happens that the schools both inherit from and attack one another over many centuries.

What does the phrase "qi rides the wind and scatters, is retained where it meets water" mean, and where does it belong?

This is the sentence regarded as the founding declaration of feng shui: qi scatters when it meets wind and stops when it meets water. The original text lies in the Book of Burial (Táng Thư), in the version preserved in the Complete Library of the Four Treasuries. The book is commonly attached to Guo Pu, who according to the Book of Jin, volume 72, Biographies 42 (Biography of Guo Pu) compiled by Fang Xuanling and colleagues in 648, lived from around 276 to 324, from the Western Jin into the Eastern Jin.

It must be said plainly at once: whether the Book of Burial is genuinely by Guo Pu remains an open question. According to the Annotated Catalog of the Complete Library of the Four Treasuries, Masters section, Divination category 2, entry for the one-volume Book of Burial compiled by Ji Yun and colleagues in 1782, the Book of Jin only says Guo Pu received the Qing Nang zhong shu, not that he wrote the Book of Burial; the Tang bibliography lists other burial texts but does not record one by Pu; only the Song bibliography records a one-volume Book of Burial by Pu, meaning the book appeared from the Song era; it was later expanded to as many as 20 sections, Cai Yuanding abridged it to 8, and Wu Cheng divided it into inner, outer and miscellaneous sections. The original title was Book of Burial, and only later generations, honoring the book, renamed it the Burial Classic. The catalog entry concludes that the book borrows a name (attributed). The book Feng shui co dai Trung Quốc: ly luan va thuc tien, volume 2, lists Guo Pu among the representative figures of the Form and Method school, while also recording the legend that he received this art from a hermit surnamed Guo of Hedong. There is a gap between the two accounts: the legend accepts Guo Pu as the founder, while modern textual scholarship can only say that a text bearing his name was transmitted and had influence.

The two great streams: where did Form and Configuration and Li Qi branch from?

According to the Annotated Catalog of the Complete Library of the Four Treasuries, Masters section, Divination category 2, entry for the one-volume Book of Burial, China has had two great schools since ancient times. The Form and Method school (also called Form and Configuration, Dragon's Head, Dragon Body, the Form school, Jiangxi) centers on the direction of the dragon veins of mountains and rivers, emphasizes the bright hall, the sand and the water, and places each house within its objective environment for examination. Because its origin and range of transmission were mainly in Jiangxi, it is also called the Jiangxi method. This school demands field visits, with eyes to see and feet to walk, and so it has contributed much practical geographical knowledge.

The Li Qi school (also called the directional school, the ancestral temple school, the dwelling school, the luopan school) combines qi theory, yin and yang, the five phases, the eight trigrams, the twelve earthly branches, the twenty-four solar terms, destiny and various prohibitions into a complex theoretical system. The same book records that Qiu Yanhan of the Tang dynasty increased the luopan's directions from twelve to twenty-four, and that figures such as Yang Junsong, Zeng Wendi, Lai Wenjun, Liao Yu, Zhang Ziwei and Cai Mutang all discussed both form and configuration and li qi. In other words, the boundary between the two schools in practice is not as clean as the names suggest: many masters used both.

On Yang Junsong: according to the Annotated Catalog of the Complete Library of the Four Treasuries, Masters section, Divination category 2, entry for Qing Nang Ao Yu and Qing Nang Xu compiled by Ji Yun and colleagues in 1782, he is the Tang-era author to whom the Qing Nang Ao Yu, a book devoted to feng shui, is ascribed. The book Feng shui co dai Trung Quốc: ly luan va thuc tien, volume 2, places Qing Nang Ao Yu among the representative works of the Li Qi school, and lists Yang Junsong among the representative figures of the Form and Method school. This is a typical example showing that the same person and the same book are placed in two different schools by different documents.

Why are they called Jiangxi and Fujian?

Naming by place reflects the region of transmission, not the technical nature. The Form and Configuration school is tied to Jiangxi because its origin and range of transmission were concentrated there, according to Feng shui co dai Trung Quốc: ly luan va thuc tien, volume 2. The Li Qi school is often called the Fujian school in many popular documents, and is also called the directional school. Because the names follow regions, learners easily mistake them for two absolutely opposed traditions, whereas in fact many old books teach a combination of both: examine the lay of the land first, then calculate direction and timing.

San He, San Yuan, Bát Trạch, Huyền Không: how do they relate to one another?

These are specific technical systems within the Li Qi stream, or blends of both streams, not four peer schools that branched off at the same time.

• San He uses the earthly branch system and the twelve stages of life cycle, grouping the mountains into San He combinations (such as Shen, Zi and Chen combining into the Water combination). This system is closer to the branch calendar and BaZi than to the nine stars.
• San Yuan divides time into three yuan, each yuan into three yun, nine yun in total, tied to the cycle of the nine stars. The book by Shen Zhureng, Trach van tan an, translated and edited by Lê Việt Anh, records that Huyền Không study takes the four aspects of Form, Principle, Qi and Number as its core and uses "the moving mouth at the facing direction" as the basis for judgment.
• Bát Trạch is the simplest system in this group: it takes birth year and gender to derive the destiny trigram (East four destinies, West four destinies), then compares this with the eight directions of the house to find good and bad directions. Bát Trạch needs no nine stars and no yun, so it is easy for general use.
• Huyền Không uses the nine flying stars, combining yun and facing direction, and judges by the star chart. Trach van tan an records that Huyền Không study developed strongly in the Song era thanks to Wu Jingluan, that in the Ming era there was Jiang Dahong with Di li bian zheng shu, and that in the Qing era there was Shen Zhureng with Shen shi Huyền Không hoc and Di li bian zheng jue yao.

The boundary between San Yuan and Huyền Không is drawn differently by each book. Some documents treat Huyền Không as a branch of San Yuan, others treat San Yuan as the theoretical part concerning timing while Huyền Không is the technical part of flying stars, and still others merge them as "San Yuan Huyền Không". The book by Shen Zhureng, Trach van tan an, uses the phrase "Huyền Không study" for the whole system, including the San Yuan Nine Yun part. So when reading documents, one must check whether the author is using the term in a narrow or a broad sense.

Which compass does each school use?

The compass (la kinh) is not a fixed tool. The la kinh changed across the ages, from early versions with only a basic directional ring to versions integrating many systems such as Bát Trạch, Huyền Không Flying Stars and Liu Yao. The emergence of different schools directly affected how the la kinh was constructed: the Dragon's Head school leans toward analyzing the forms of mountains and rivers, while the Li Qi school emphasizes the calculation rings on the la kinh for locating qi channels.

Jiang Dahong condemned Bát Trạch as a forged book, so why is Bát Trạch the most widespread in Vietnam?

According to Tian yuan wu ge, section Lun yang zhai, by Jiang Dahong, he refutes the Bát Trạch wandering-year method: arranging Tian Yi and Fu De is hardly the true Bát Trạch of the Duke of Zhou; the wandering-year method divides fortune and misfortune, and if it does not match San Yuan then the effort is wasted; there are books transmitted but none of them verified. Thus Jiang refutes the Bát Trạch wandering-year method; he does not call a specific book a forged text. The book by Shen Zhureng, Trach van tan an, p. 45, only says Jiang helped people of his time see the true and false in geomancy, and does not mention Bát Trạch. The book Feng shui co dai Trung Quốc: ly luan va thuc tien, volume 2, also records that many later people criticized the Li Qi school, calling it "the pinnacle of bad practice", arguing that this school does not discuss form and configuration but only uses trigram arrangement, heavenly stars and li qi to bewilder people. Bát Trạch falls within that criticized group.

So why is Bát Trạch still the most widespread in Vietnam? Because it has three practical features: easy to learn, needing only birth year and gender to produce the destiny trigram; easy to apply, needing only a comparison of the house's eight directions with the destiny trigram to produce four good and four bad directions; and independent of timing, so it needs no updating by yun. For someone buying a house, renting a house or placing a desk, this is a level of analysis sufficient for use without needing nine stars or flying stars. The lookup tools on the Nhật Nguyệt site such as bat-trach and xem-nha-dat follow Bát Trạch for that reason: suited to most ordinary users, simple input data, easy-to-interpret results.

It should be said clearly: a system being widespread does not mean it is more correct than other systems, and a master's criticism does not mean the criticized system is worthless for every purpose. These are two different questions: popularity is a matter of social reception, while right and wrong is a matter on which there is no scientific conclusion.

How do the schools criticize one another?

The book Feng shui co dai Trung Quốc: ly luan va thuc tien, volume 2, cites two arguments criticizing the Li Qi school. First, this school is said not to discuss form and configuration, using only trigram arrangement to bewilder people. Second, the doctrines of heavenly stars and li qi are unreliable, because if the dragon and the burial point are not accurate then even auspicious heavenly stars fail, while if the dragon and burial point are correct then even inauspicious heavenly stars prosper; therefore intelligent people seek only to find the true or false point, and do not emphasize whether the heavenly stars are good or bad.

This argument has one strength: it sets an order of priority. If the lay of the land is wrong, then all directional calculations are meaningless. But it also has a weakness: it assumes that a "true burial point" can be determined objectively, whereas the criteria for determining a true point are themselves set by people and also change with the times. One line of reasoning holds that not every feng shui school transmitted to the present brings the same practical value, and that distinguishing true from false requires real-world testing.

Summary timeline

Where should a learner begin?

There is no single right answer for everyone. If the goal is quickly looking up a house's direction by age, Bát Trạch is a reasonable starting point because the data is simple. If the goal is to understand why the schools disagree, one needs to read documents from both the Form and Configuration school and the Li Qi school, because each side describes the other in its own language. And one should remember that this entire field has no scientifically verified evidence, so any judgment of fortune or misfortune should be treated only as cultural reference, and should not be used as the sole basis for decisions about finances, health or other important matters.