Structural Analysis, Meaning, and Philosophical Inquiry of the Hexagram Huotian Dayou (Fire Over Heaven)

Appendix 2: The Numerology of the Da You Hexagram

I. The Numbers of the Da You Hexagram

In the Earlier Heaven (Xiantian) Trigram sequence, Da You (Upper Li, Lower Qian) corresponds to Li (Number Three) above Qian (Number One).

In the Later Heaven (Houtian) Trigram sequence, Upper Li is in the South, and Lower Qian is in the Northwest. South represents Fire, and Northwest represents Heaven.

II. The Line Count of the Da You Hexagram

The total number of Yang lines in Da You: Initial Nine (9), Nine Two (9), Nine Three (9), Nine Four (9), Upper Nine (9)—five nines. The Yin line is Six Five (6). The sum is $5 \times 9 + 6 = 51$.

The Xi Ci Zhuan, Part I, states: "The Great Elaboration number is fifty, and its application is forty-nine" (大衍之数五十，其用四十有九). The Great Elaboration number fifty is close to the total line count of 51 for Da You; this might not be coincidental.

III. Numerical Characteristics of Da You

The configuration of five Yang lines and one Yin line makes Da You a hexagram where Yang is predominant. Hexagrams with one Yin line among five Yangs total six: Da You, Gou, Xiao Chu, Kuai, Tong Ren, and Lü (Treading). (In fact, there are exactly six hexagrams with one Yin among five Yangs, corresponding to the six possible positions where the Yin line can reside.)

These six hexagrams of one Yin among five Yangs have different natures, and Da You, with its Yin line occupying the Fifth Position (the position of honor), is among the most revered of these. This also explains the high status of Da You from a numerological perspective.