Chapter Six: The Conjunction of Wu and Wei — Sun and Moon Shining as One, and the Fire (Earth) of Supreme Yin

I. Astronomical and Etymological Investigation

Wu corresponds to the fifth month establishment. It resembles a pestle; Yin and Yang alternate. The Shuowen states: "Wu means 'to resist' (wu). In the fifth month, Yin breath resists and opposes Yang."

Wei corresponds to the sixth month general. It resembles a tree laden with branches and leaves. The Shuowen states: "Wei means 'flavor' (wei). In the sixth month, there is savor and flavor."

Question: Wu is the supremely Yang Fire; Wei is dry Earth. When these two conjoin, do they transform into Fire or Earth$16 Ancient texts contain much debate on this point.

II. In-Depth Analysis from the Perspective of High Antiquity

This pair is the most astronomically distinctive among the Six Conjunctions, and is called "the Meeting of Sun and Moon."

Wu, in the Former Heaven (Xiantian) trigram arrangement, corresponds to Qian (the Creative); in the Later Heaven (Houtian) arrangement, to Li (the Clinging, Fire). Wei, in the Former Heaven, corresponds to Xun (the Gentle, Wind); in the Later Heaven, to Kun (the Receptive, Earth).

1. The Singular Breath of the Celestial Origin and the Great Plan of the Shangshu:
   • Wu is the Sun (ri); Wei is the Moon (yue), the Great Yin. In ancient astronomy, the dividing line of Wu and Wei is the celestial sphere's "prime meridian" (called in antiquity the "Distinct Palace," shugong).
   • When the Dipper handle points to Wu (the Summer Solstice), the Sun lodges in Wei.
   • This is the moment of Yang breath at its fullest. At the Summer Solstice the first Yin is born, yet thermal intensity reaches its peak in the month of Wei.
2. The Debate over Qi-Transformation — Fire and Earth Share a Common Source:
   • The mainstream view: transformation into Fire. Wu-Fire is in command of the season; the Ding-Fire (residual breath) within Wei resonates in answer. Wei is originally dry Earth — like parched land that ignites upon encountering Fire. Thus the conjunction of Wu and Wei intensifies the blaze.
   • The alternative view: transformation into Earth. Fire engenders Earth; Wu-Fire engenders Wei-Earth, and ultimately the breath returns to Earth.
   • The correct interpretation of high antiquity: depends on the specific context, but the essential nature is that of "scorching, desiccating breath."
   • In the Suwen, chapter "Great Treatise on the Celestial Origin" (Tianyuan Jida Lun): beneath the Sovereign Fire, the Yin essence sustains it. The conjunction of Wu and Wei is "the ultimate fusion of light and heat."
3. Philosophical Metaphor — The Joyous Audience of Sovereign and Minister:
   • Wu is the sovereign (Li, the Sun); Wei is the populace (Kun, Earth).
   • The conjunction of Wu and Wei is the image of the sovereign presiding over all under Heaven and the myriad people yielding allegiance.
   • Unlike the "concealment in the dark of night" of Zi-Chou, Wu-Wei is "conspicuous glory in broad daylight."

Conclusion The conjunction of Wu and Wei transforming into Fire (or dry Earth) is the "Fire of Supreme Flourishing." It represents the zenith of a thing's development, the apex of glory — and at the same time the eve of "when fullness reaches its extreme, decline must follow." Its breath is purely Yang yet carries a trace of Yin (the Yi-Wood within Wei): the final eruption of energy before maturity and harvest.