The Structure of the I Ching: Trigrams, Hexagrams & Lines
The I Ching is built from simple parts: eight trigrams combine into 64 hexagrams, each made of six lines. This guide explains the architecture so the system feels less mysterious.
The Eight Trigrams (Bagua)
Eight trigrams are the building blocks. Each is a stack of three lines, either broken (yin) or unbroken (yang).
They are Qian (heaven), Kun (earth), Zhen (thunder), Kan (water), Gen (mountain), Xun (wind), Li (fire), and Dui (lake).
How Hexagrams Form
A hexagram is two trigrams stacked: one below, one above. With 8 × 8 possible pairs, there are 64 hexagrams.
The lower trigram often represents the inner or starting condition; the upper represents the outer or developing condition.
The Six Lines
Each hexagram has six lines, read bottom to top. Positions 1–3 relate to the lower trigram; 4–6 to the upper.
Lines can be stable (young) or changing (old). Changing lines shift the hexagram into its transformed partner.
Why Structure Matters
Knowing the structure helps you see relationships between hexagrams. Many are pairs or inverses of each other.
Once you know the eight trigrams, every hexagram becomes readable as a combination of two familiar images.
Frequently Asked Questions
How many trigrams are there?
Eight, called the Bagua.
How are 64 hexagrams made?
By combining any two of the eight trigrams (8 × 8 = 64).
What do the six lines represent?
Stages of development, read from bottom to top.
These are practical tips I have gathered from keeping guinea pigs over the years. Hope they help you on your journey! Feel free to leave a comment — I read and respond to every message.
