1. Why There Are Exactly Eight
Each line has two possible states, and a trigram has three lines, so there are 2 × 2 × 2 = 8 trigrams. Stack two trigrams and you get a six-line hexagram: 8 × 8 = 64, which is why the I Ching has 64 hexagrams. The set of eight is called the bagua, which simply means “eight trigrams.” Feng shui borrowed the same name for its room map.
Lines are always read from the bottom up. The bottom line is the first, the top line the third. This matters: Thunder and Mountain contain the same lines, one solid and two broken, and differ only in where the solid line sits.
Learn the eight trigrams and every one of the 64 hexagrams becomes a readable pair instead of a random shape.
2. The Eight Trigrams at a Glance
The images, qualities and family roles come from the Shuo Gua (Discussion of the Trigrams), one of the commentaries traditionally attached to the I Ching. English names follow the Richard Wilhelm translation. The element column follows the later Five Element pairing used in feng shui.
| Trigram | Image | Quality | Family | Element | Lines (bottom → top) |
|---|---|---|---|---|---|
| Qian The Creative | Heaven | Strong, initiating | Father | Metal | solid, solid, solid |
| Kun The Receptive | Earth | Yielding, devoted | Mother | Earth | broken, broken, broken |
| Zhen The Arousing | Thunder | Movement, shock | Eldest son | Wood | solid, broken, broken |
| Kan The Abysmal | Water | Danger, depth | Middle son | Water | broken, solid, broken |
| Gen Keeping Still | Mountain | Stillness, rest | Youngest son | Earth | broken, broken, solid |
| Xun The Gentle | Wind / Wood | Penetrating, gradual | Eldest daughter | Wood | broken, solid, solid |
| Li The Clinging | Fire | Light, clarity | Middle daughter | Fire | solid, broken, solid |
| Dui The Joyous | Lake | Joy, openness | Youngest daughter | Metal | solid, solid, broken |
3. The Trigram Family: A Built-In Memory Trick
The Shuo Gua describes the trigrams as a family. Heaven (three solid lines) is the father and Earth (three broken lines) is the mother. The other six are their children, and one rule sorts them all:
- Sons have one solid line among two broken ones; daughters have one broken line among two solid ones.
- The position of that odd line gives the birth order: bottom = eldest, middle = middle, top = youngest.
- So Thunder (solid at the bottom) is the eldest son, Water the middle son, Mountain the youngest son; Wind (broken at the bottom) is the eldest daughter, Fire the middle daughter, Lake the youngest daughter.
Find the line that differs from the other two: its type gives the gender, its position gives the birth order.
4. Two Arrangements: Early Heaven and Later Heaven
The trigrams are traditionally laid out in a circle in two different orders. The Early Heaven (Fu Xi) arrangement pairs opposites across the circle, such as Heaven facing Earth and Fire facing Water. It describes an ideal balance. The Later Heaven (King Wen) arrangement follows the cycle of seasons and directions, and it is the one most feng shui schools use for compass directions.
| Trigram | Early Heaven | Later Heaven |
|---|---|---|
| Qian (Heaven) | South | Northwest |
| Kun (Earth) | North | Southwest |
| Zhen (Thunder) | Northeast | East |
| Kan (Water) | West | North |
| Gen (Mountain) | Northwest | Northeast |
| Xun (Wind / Wood) | Southwest | Southeast |
| Li (Fire) | East | South |
| Dui (Lake) | Southeast | West |
Traditional Chinese diagrams put south at the top, so a printed bagua may look upside down to Western readers. For how the Later Heaven order becomes a room map, see our bagua map guide.
Early Heaven shows balance between opposites; Later Heaven shows change through the seasons.
5. How Two Trigrams Make a Hexagram
Every hexagram is a lower trigram (lines 1–3) with an upper trigram (lines 4–6) on top. Commentators often read the lower one as the inner situation and the upper one as the outer. Hexagrams 1 and 2 are simply Heaven doubled and Earth doubled. A few more examples:
11 · Peace (Tai)
Upper: Kun (Earth) · Lower: Qian (Heaven)
Heaven rises and Earth descends, so the two meet: an image of harmony.
12 · Standstill (Pi)
Upper: Qian (Heaven) · Lower: Kun (Earth)
Heaven above and Earth below drift apart: an image of stagnation.
24 · Return (Fu)
Upper: Kun (Earth) · Lower: Zhen (Thunder)
Movement stirring beneath the earth: the first sign of a turning point.
63 · After Completion (Ji Ji)
Upper: Kan (Water) · Lower: Li (Fire)
Water over fire, like a pot on a flame: things are in place but need tending.
Notice that 11 and 12 use the same two trigrams in opposite positions and mean nearly opposite things. Position matters as much as content.
6. Common Beginner Mistakes
❌ Reading lines top-down
Lines count from the bottom. Reading from the top swaps Thunder with Mountain and Wind with Lake.
❌ Mixing the two arrangements
Heaven is south in Early Heaven but northwest in Later Heaven. State which arrangement you are using.
❌ Treating images as fixed predictions
Water signals difficulty or depth, not a literal flood. The images are prompts for reflection.
7. Use AI as a Study Partner
After casting a hexagram, you can ask Prism's AI reader to talk through what its upper and lower trigrams suggest about your question.
Check the trigram identification against the table above yourself. The AI is a discussion partner, not an authoritative translation of the I Ching.
8. Sources and Further Reading
- Chinese Text Project, Shuo Gua: the original commentary with an English translation.
- Richard Wilhelm (trans.), rendered into English by Cary F. Baynes, The I Ching or Book of Changes, Princeton University Press, 1950: source of the English trigram names.