A Detailed Explanation of the Differences Between the Generation and Restriction of Heavenly Stems and Earthly Branches

The interaction and constraint between Heavenly Stems and Earthly Branches serve as an important basis for judging the overall auspiciousness or inauspiciousness of a 命理 (natal chart) in fate theory. What kind of restrictive relationships occur between Heavenly Stems and Earthly Branches when assessing the fortune of a natal chart? Can the Earthly Branches in the Eight Characters also restrict the Heavenly Stems?

Differences in the Interaction between Heavenly Stems and Earthly Branches

1. Ten Heavenly Stems
The Ten Heavenly Stems are 甲 (Jiǎ), 乙 (Yǐ), 丙 (Bǐng), 丁 (Dīng), 戊 (Wù), 己 (Jǐ), 庚 (Gēng), 辛 (Xīn), 壬 (Rén), 癸 (Guǐ).
Heavenly Stems represent the external aspects, while Earthly Branches represent the internal aspects (such as thoughts and personality).
When interpreting annual fortunes, Heavenly Stems take precedence. Their relationships are simple, mainly involving "生 (generation)" and "克 (restriction)" or "合 (combination)":
Generation: For example, 甲木 (Jiǎ Wood) generates 丙火 (Bǐng Fire), and 丙火 (Bǐng Fire) generates 戊土 (Wù Earth).
Restriction: For example, 甲木 (Jiǎ Wood) restricts 戊土 (Wù Earth), and 戊土 (Wù Earth) restricts 壬水 (Rén Water).
Heavenly Stems are dynamic and can interact freely, though the restrictive power weakens when they are separated.
2. Twelve Earthly Branches
The Twelve Earthly Branches are 子 (Zǐ), 丑 (Chǒu), 寅 (Yín), 卯 (Mǎo), 辰 (Chén), 巳 (Sì), 午 (Wǔ), 未 (Wèi), 申 (Shēn), 酉 (Yǒu), 戌 (Xū), 亥 (Hài).
Earthly Branches are static and can only exert their power through Heavenly Stems, serving as the source of the Stems' energy.
Earthly Branches cannot interact randomly; their effects must occur through relationships such as 刑 (punishment), 冲 (conflict), 合 (combination), or harm, which can be triggered by annual and decadal. Without these conditions, Earthly Branches remain inactive.
Can Earthly Branches in the Eight Characters Restrict Heavenly Stems?
1. Restriction within the Same Column
Generation or restriction between Heavenly Stems and Earthly Branches can only occur within the same column (本柱). Branches and Stems in different columns cannot directly interact.
2. Restriction between Earthly Branches
Interaction between Earthly Branches must rely on 刑 (punishment), 冲 (conflict), combination, or harm; otherwise, direct restriction is generally impossible.
3. Effects of Annual and Decadal Year and Luck
When the stems and branches of decadal luck or annual luck interact with the natal chart, Stems affect Stems, and Branches affect Branches.
4. Restriction by Momentum
In addition to direct interaction within the same column, the Five Elements of different-column Branches and Stems can only exert a "momentum-based" restrictive effect, which is weak.
If the cumulative momentum reaches a certain threshold, it can approximate direct restriction.
5. Interaction between Year-Luck and Natal Chart
This follows the principle that Stems affect Stems and Branches affect Branches. The prosperity or decline of the Five Elements in the natal chart is determined by the balance of forces, which reflects their state rather than absolute gain or loss.
6. Special Notes on Earthly Branches
The four Earthly Branches 辰 (Chén), 戌 (Xū), 未 (Wèi), and 丑 (Chǒu) have unique properties:
辰 (Chén) is a water reservoir, 戌 (Xū) and 未 (Wèi) are fire reservoirs, 丑 (Chǒu) and 未 (Wèi) are metal reservoirs, and 未 (Wèi) is a wood reservoir.
寅 (Yín) enters storage when encountering 未 (Wèi), 申 (Shēn) enters storage when encountering 丑 (Chǒu), 巳 (Sì) enters storage when encountering 戌 (Xū), and 亥 (Hài) enters storage when encountering 辰 (Chén).
戌 (Xū) is "dry earth," which severely restricts water and cannot generate metal (instead, it weakens metal).
丑 (Chǒu) and 辰 (Chén) are "wet earth," which weakly restricts water but can directly generate metal and dim fire.