Two Arrangements of the Bagua
In I Ching tradition, the Eight Trigrams do not have only one fixed arrangement. There are two main systems, each tied to a different legend and a different practical purpose: the Early Heaven arrangement (also called the Fuxi Bagua) and the Later Heaven arrangement (also called the King Wen Bagua). Distinguishing between the two is important, since they place the trigrams in different positions for the same direction, which can lead to interpretive errors if confused.
Early Heaven Bagua (Fuxi Arrangement)
According to legend, the Early Heaven Bagua was created by Fuxi, one of the mythical Three Sovereigns of ancient China, based on his observation of the River Map (Hà Đồ), a pattern said to have appeared on the back of a dragon-horse that emerged from the Yellow River. This arrangement represents the "substance" (thể) layer: the original, ideal, static state of the cosmos before all things began to move and change.
The defining feature of the Early Heaven Bagua is the perfect symmetry between opposing pairs of trigrams: Càn (Heaven) faces Khôn (Earth) along a north-south axis; Ly (Fire) faces Khảm (Water) along an east-west axis; Chấn (Thunder) faces Tốn (Wind) diagonally; and Cấn (Mountain) faces Đoài (Lake) diagonally. This layout expresses the principle of balanced yin and yang, opposing forces that complement each other harmoniously in a static state.
The Early Heaven arrangement is used mainly for studying yin-yang philosophy, as the theoretical basis for the structure of the 64 I Ching hexagrams, and in some feng shui schools as an underlying "substance" layer placed beneath the compass to support deeper readings of qi and the hidden relationships between directions, rather than being used directly to determine practical directions.
Later Heaven Bagua (King Wen Arrangement)
The Later Heaven Bagua is said to have been rearranged by King Wen of Zhou, based on the Luo Shu (Lạc Thư), a pattern said to have appeared on the back of a divine turtle that emerged from the Luo River. This arrangement represents the "function" (dụng) layer: the world after all things have come into being and begun moving and changing continuously through the cycle of the four seasons.
In the Later Heaven Bagua, the trigrams' positions are tied directly to the eight directions and the yearly cycle of qi: Ly (Fire) in the South, Khảm (Water) in the North, Chấn (Thunder) in the East, Đoài (Lake) in the West, Tốn (Wind) in the Southeast, Khôn (Earth) in the Southwest, Càn (Heaven) in the Northwest, and Cấn (Mountain) in the Northeast. This layout is not perfectly symmetrical like the Early Heaven arrangement; instead, it reflects the actual sequence of qi's growth and decline, much like the course of a day, a year, or a human life.
When Is Each Arrangement Used?
Because the Later Heaven Bagua describes the phenomenal, actively changing world, it is the arrangement most commonly used in applied feng shui: determining a home's direction, calculating Eight Mansions (Bát Trạch) groupings, laying out Flying Star (Cửu Cung Phi Tinh) charts, and practicing divination systems such as Qi Men Dun Jia. When a feng shui practitioner refers to "the Càn direction" or "the Ly sector," they are using Later Heaven positions.
The Early Heaven Bagua, by contrast, leans toward philosophical reasoning and academic study: explaining the origin of yin and yang, forming the theoretical basis for some advanced techniques in Xuan Kong (flying star) feng shui, such as identifying corresponding mountain/facing relationships or the hidden nature of dragon veins (long mạch), and providing the foundation for understanding the deeper meaning of the hexagrams before they are applied to daily life through the Later Heaven arrangement.
Conclusion
In short, the Early Heaven Bagua can be thought of as the "original blueprint," while the Later Heaven Bagua is the "operating manual" of the actual world. Those new to home feng shui, direction analysis, or Eight Mansions should focus on the Later Heaven Bagua, since it is the arrangement applied directly in practice; the Early Heaven Bagua is more relevant when seeking a deeper understanding of the philosophy and original structure of the I Ching.
