Eight Trigrams

Trigrams are first three-line structures, then names and natural imagery. Qian is all yang, Kun all yin; Kan has yang in the middle with yin outside, while Li reverses that arrangement. Distinguishing line pattern, name and imagery is more useful than reducing each trigram to an element label.

Three lines with two polarities have 2³ = 8 arrangements: Qian, Dui, Li, Zhen, Xun, Kan, Gen and Kun. Stacking two gives 8 × 8 = 64 six-line hexagrams. This Zhouyi structure also underlies Liuyao trigram identification and palace membership.

Shuo Gua associates Qian with Heaven, Dui Lake, Li Fire, Zhen Thunder, Xun Wind, Kan Water, Gen Mountain and Kun Earth. With bottom-to-top yang=1 and yin=0, Qian is 111, Kun 000, Kan 010 and Li 101. Family imagery assigns Zhen/Kan/Gen and Xun/Li/Dui to eldest, middle and youngest sons and daughters, referring to birth order.

Lower Zhen and upper Kan form Zhun, Water over Thunder. Read Zhen’s yang/yin/yin first from the bottom, then Kan’s yin/yang/yin. The descriptive name lists upper Water before lower Thunder. Position is part of the information, not merely two image words.

Najia adds branches and palace-based positions; Mei Hua uses its own body/use and nuclear/changed methods. The shared trigram structure does not make those subsequent procedures interchangeable.