What Are the Four Corners?
The Four Corners (Siyu) refer to the four Earthly Branches Yin, Shen, Si, and Hai, corresponding respectively to the northeast, southwest, southeast, and northwest diagonal directions. They are also known as the "Four Corner Positions" or "Four Diagonals" (Siwei).
In terms of Hidden Stems, the defining characteristic of the Four Corners is that each branch conceals three Heavenly Stems (Primary Qi + Secondary Qi + Remaining Qi), making them the four branches with the richest Hidden Stem content among the twelve branches:
| Branch | Direction | Primary Qi | Secondary Qi | Remaining Qi |
|---|---|---|---|---|
| Yin | Northeast | Jia Wood | Bing Fire | Wu Earth |
| Shen | Southwest | Geng Metal | Ren Water | Wu Earth |
| Si | Southeast | Bing Fire | Geng Metal | Wu Earth |
| Hai | Northwest | Ren Water | Jia Wood | — |
Why Do the Four Corners Have the Most Complex Hidden Stems?
The Four Corners sit at the transitional zones between two seasons, serving as hubs where the qi of the Five Elements is handed over:
- Yin: Winter-Spring transition → Conceals Jia Wood (spring Wood) + Bing Fire (soon-to-prosper Fire) + Wu Earth (transitional Remaining Qi)
- Shen: Summer-Autumn transition → Conceals Geng Metal (autumn Metal) + Ren Water (soon-to-prosper Water) + Wu Earth
- Si: Spring-Summer transition → Conceals Bing Fire (summer Fire) + Geng Metal (soon-to-prosper Metal) + Wu Earth
- Hai: Autumn-Winter transition → Conceals Ren Water (winter Water) + Jia Wood (soon-to-prosper Wood)
Precisely because the Four Corners sit at the volatile nodes of seasonal alternation — where the previous season's Remaining Qi has not yet dissipated, the current season's Primary Qi is in command, and the next season's Secondary Qi has already arisen — three qi layers coexist within a single branch, making their Hidden Stems naturally the most complex.
Seasonal Transition and Energy Circulation
The Four Corners are where "Birth qi" (Shengqi) resides — Yin is the Birth (Changsheng) stage of Fire, Shen the Birth of Water, Si the Birth of Metal, and Hai the Birth of Wood. As Birth-stage locations, the Four Corners contain nascent force while still carrying the residue of the old season, making them crucial conduits for the transformation of energy from old to new.
The Four Corners and the Destiny Chart
- When the Day Branch falls on a Four Corner, the person tends to be multi-faceted and highly adaptable, though their inner world may be rather complex
- Charts with many Four Corner branches possess rich Hidden Stems and abundant opportunities for qi communication between heaven and earth, giving the chart greater structural flexibility
- When Four Corners are clashed (Yin-Shen clash, Si-Hai clash), their complex Hidden Stems mean the clash often includes elements of union and transformation, making the dynamics more subtle than Cardinal Direction clashes