TL;DR: Thái Ất Thần Số is an ancient divination art within the Tam Thức (Three Styles), alongside Kỳ Môn Độn Giáp and Lục Nhâm, using a board to infer great matters such as the fate of the nation, military affairs and natural disasters. The earliest surviving text of this art is the Thái Ất Kim Kính Thức Kinh, compiled by Vương Hi Minh in the Tang dynasty. Thái Ất starts from palace 1, moves forward through the eight palaces, never entering the central palace, three years to each palace; its two eyes are Văn Xương (Literary Glory) and Thủy Kích, divided into the Host and Guest sides. This is an ancient divination art, not a tool for predicting real events.
What is Tai Yi Shen Shu and is it really the foremost of the Three Styles?
Tai Yi Shen Shu (Thái Ất Thần Số) is an ancient Eastern divination method that, together with Qi Men Dun Jia (Kỳ Môn Độn Giáp) and Liu Ren (Lục Nhâm), makes up the Three Styles (Tam Thức). This method uses a divination board to infer great matters such as the fate of a nation, military affairs and natural disasters. The earliest surviving book of this school is the Tai Yi Jin Jing Shi Jing (Thái Ất Kim Kính Thức Kinh), in ten volumes, compiled by Wang Xi Ming (Vương Hi Minh) under imperial order during the Kai Yuan era of the Tang dynasty; the Siku Quanshu Zongmu Tiyao (Tứ Khố Toàn Thư Tổng mục đề yếu) notes that the book contains a section calculating accumulated years up to the Jing You era of the Song dynasty, meaning later generations added it, and records that the Western Xia ruler Yuan Hao once used the Tai Yi Jin Jian method.
As for the order within the Three Styles, there are two accounts. The Tiyao of the Liu Ren Da Quan (Lục Nhâm Đại Toàn) in the Siku writes: Liu Ren, together with Dun Jia and Tai Yi, were called the Three Styles by later ages, and Liu Ren was transmitted the longest. Later generations often list Tai Yi before the other two methods, usually citing the scope of matters: Tai Yi aims at the fate of a nation, while the Tiyao of the Jin Jing Shi Jing writes that methods such as Xing, Ping, Ren and Dun only infer a single person or a single time. That same Tiyao argues that the order and disorder, rise and fall of dynasties rest on the virtue of the ruler, and cannot be known by calculation, and criticises the book's section on verifications as mostly erroneous. It must be said clearly from the outset: this is an ancient divination method, not used to predict real events, and no substitute for scientific forecasting or practical decisions.
How to place Tai Yi into the palaces according to the Jin Jing Shi Jing
According to the Jin Jing Shi Jing, to place Tai Yi one must take the accumulated year count from the upper epoch Jia Zi. First discard multiples of 360 (the cycle method), from the remainder discard multiples of 72 (the epoch method), from the remaining remainder discard multiples of 24 (the minor cycle method of Tai Yi), then divide by 3 to get the palace number. Tai Yi starts from palace 1, moves forward through the eight palaces, does not enter the central palace (palace 5), and stays three years in each palace, so 24 years complete one circuit. The base accumulated year count differs from book to book: Wang Xi Ming records that from the upper epoch to the Jia Zi year of the twelfth year of the Kai Yuan era (724) is 1,937,281, while according to Ho Peng Yoke, a 17th-century Ming dynasty Tai Yi book uses 10,155,341.
How do the nine palaces of Tai Yi number differently from the Luo Shu?
Unlike the Luo Shu used by Qi Men and Xuan Kong, the nine palaces of Tai Yi according to the Jin Jing Shi Jing are numbered by trigram position: palace 1 at Qian, 2 at Li, 3 at Gen, 4 at Zhen, 6 at Dui, 7 at Kun, 8 at Kan, 9 at Xun, palace 5 in the centre and Tai Yi does not enter it. Each palace corresponds to the provinces of ancient China, showing that this method reads by the field allocations of the whole country rather than by a single person.
| Palace number | Trigram | Direction | Corresponding provinces |
|---|---|---|---|
| 1 | Qian | Northwest | Ji province, Bing province |
| 2 | Li | South | Jing province |
| 3 | Gen | Northeast | Qing province |
| 4 | Zhen | East | Xu province |
| 6 | Dui | West | Yong province |
| 7 | Kun | Southwest | Liang province, Yi province |
| 8 | Kan | North | Yan province |
| 9 | Xun | Southeast | Yang province |
What are the main components of the Tai Yi board?
According to the Jin Jing Shi Jing, Tai Yi is the ruler, the two Mu are assistant ministers, the five generals determine host and guest, and the eight gates divide victory and defeat. The two Mu consist of Shi Ji (Thủy Kích, the character 始擊, shui meaning beginning; also called the upper Mu, the essence of the planet Mars, belonging to the Guest side) and Wen Chang (Văn Xương, the lower Mu, the essence of Saturn, belonging to the Host side). The five generals consist of the Tai Yi supervising general, the two Mu, and the great general and lesser general of Host and Guest. The Ji spirit is found by taking the accumulated years, discarding multiples of 60, and counting the remainder backwards through the twelve earthly branches starting from Yin. According to Ho Peng Yoke (Chinese Mathematical Astrology, 2003), the Tai Yi board is divided into sixteen parts corresponding to sixteen spirits, and has seventy-two configurations for yang dun and seventy-two configurations for yin dun.
How are the six main patterns in Tai Yi defined?
The six main patterns according to the Jin Jing Shi Jing are Yan, Po, Qiu, Ji, Guan and Ge. Yan is when Shi Ji reaches exactly the palace of Tai Yi; if it meets the year Ji then order is thrown into chaos, ministers strong and ruler weak. Po is when the two Mu, and the great and lesser generals of host and guest, stand beside Tai Yi to left and right; standing in front is outer Po, standing behind is inner Po. Qiu is when Wen Chang or the great and lesser generals of host and guest share a palace with Tai Yi, meaning usurpation of the throne and killing. Ji is when the guest Mu stands one spirit before or after Tai Yi, which is front Ji and back Ji, or one palace before or after, which is outer palace Ji and inner palace Ji, meaning ministers encroaching on the ruler. Guan is when the Mu and the great and lesser generals of host and guest share a palace with one another; according to Wang Xi Ming the matter concerns only general against general, not reaching the ruler. Ge is when the Mu and the great and lesser generals of the guest are in the palace opposite Tai Yi, meaning high and low are separated.
| Pattern | Definition according to the Jin Jing Shi Jing |
|---|---|
| Yan | Shi Ji reaches exactly the palace of Tai Yi; if it meets the year Ji then order is thrown into chaos, ministers strong and ruler weak |
| Po | The two Mu, and the great and lesser generals of host and guest, stand beside Tai Yi to left and right; standing in front is outer Po, standing behind is inner Po |
| Qiu | Wen Chang or the great and lesser generals of host and guest share a palace with Tai Yi, meaning usurpation of the throne and killing |
| Ji | The guest Mu stands one spirit before or after Tai Yi, which is front Ji and back Ji, or one palace before or after, which is outer palace Ji and inner palace Ji, meaning ministers encroaching on the ruler |
| Guan | The Mu and the great and lesser generals of host and guest share a palace with one another; according to Wang Xi Ming the matter concerns only general against general, not reaching the ruler |
| Ge | The Mu and the great and lesser generals of the guest are in the palace opposite Tai Yi, meaning high and low are separated |
How are Host and Guest understood in Tai Yi?
The Jin Jing Shi Jing defines host and guest by before and after, movement and stillness: when troops are deployed in the field, the side that moves first is the Guest and the side that responds after is the Host; but when at rest, the side that moves first is the Host and the side that responds after is the Guest. In interpretation, one examines the interaction between Host and Guest, not position alone.
Why do fewer people study Tai Yi than Qi Men and Liu Ren?
First, Tai Yi is bound tightly to great affairs of state, its traditional focus being the fate of a nation, natural disasters and warfare, things that modern students have little need to consult. Qi Men Dun Jia and Liu Ren can be applied to more concrete, closer matters, so they more easily find students. Second, the calculation system of Tai Yi is heavy with accumulated year counts, discarding 360, the 60 cycle, and placing positions by palace sequence. The calculation steps are long, easy to get wrong, and require cross-checking many ancient editions. Ho Peng Yoke records that among the common people Tai Yi is the least known of the Three Styles. Third, ancient editions are not entirely consistent about the base accumulated year count and some placement conventions. Students must choose a reference system themselves and state clearly which one they follow. Wang Xi Ming himself criticised Song Kun's way of setting the upper epoch as childish and redid the accumulated year calculation himself.
Tai Yi in relation to Qi Men and Liu Ren
Within the Three Styles, the three methods have a relatively clear division of labour. Tai Yi leans towards great matters, the fate of a nation, natural disasters and warfare. Qi Men Dun Jia leans towards military strategy, directions and choosing headings, used in strategy and also in concrete matters. Liu Ren leans towards concrete matters, close to everyday life. This division of labour is a traditional convention, not an absolute boundary, since the methods can still be used across one another.
Reading Tai Yi today: how should it be understood correctly?
Tai Yi Shen Shu is an ancient system of thought about the movement of time and space, recorded over many generations. Its value lies in the history of ideas and culture, not in any ability to forecast reality. Students should approach Tai Yi as an ancient divination method, reading it to understand how people of old modelled the times, not using it to decide business, health or investment. Conclusions such as Host wins or Guest wins, Fa or Qiu, have meaning only within the system, not as practical advice. Keeping an objective attitude and avoiding extreme superstition is the most appropriate approach to a subject that has a long history but lacks verifiable foundations.
