The Eight Trigrams: The Alphabet of the I Ching

Open the I Ching for the first time and you see sixty-four hexagrams: figures of six lines, each with its own name and its own story. Beneath those sixty-four lies a simpler alphabet. Every hexagram is built from two trigrams, figures of three lines, and there are exactly eight of them. Know those eight, and you read every hexagram with more depth.

Each line is either yang (solid) or yin (broken). Three lines allow eight possible combinations, and to each of them tradition attached an image from nature. Not abstract symbols, but things everyone knows: the sky above you, the ground beneath your feet, a thunderstorm clearing the air, a lake in the evening sun.

The eight images from nature

• Heaven (three yang lines): pure creative force, tirelessly in motion yet never in a hurry.
• Earth (three yin lines): the receptive that carries and nourishes everything, strong precisely by yielding.
• Thunder: the shock that sets things in motion, the beginning that erupts before you feel ready for it.
• Water: the deep that can be dangerous yet always flows on, taking every shape without losing itself.
• Mountain: the stillness that knows when enough is enough, rest that does not give way to restlessness.
• Wind: the gentle that penetrates everywhere and shapes slowly but unmistakably, the way wind shapes a landscape.
• Fire: the radiant that gives clarity, but must cling to something that feeds it.
• Lake: the joyous open water that brings people together in lightness and conversation.

Two trigrams form a hexagram

Place two trigrams on top of each other and a hexagram appears. The lower one is called the inner trigram: your inner attitude, what happens beneath the surface. The upper one is the outer trigram: how the situation shows itself outwardly, what the world asks of you. A hexagram is not a single picture, then, but a meeting between inside and outside.

Sometimes a trigram doubles itself. Hexagram 1, The Creative, is heaven above heaven: creative force without a single weak spot. Hexagram 29, The Abysmal, is water above water: danger within and without, with the lesson to keep flowing the way water does. Usually, though, two different images meet, and it is that meeting that tells the story: thunder beneath the earth is strength returning, fire beneath heaven is fellowship under a wide sky. You can find all sixty-four combinations in the hexagram overview.

A family of eight

Tradition also gives the trigrams family roles. Heaven is the father, earth the mother, and the six others are their children. Thunder is the eldest son, water the middle son, mountain the youngest; wind is the eldest daughter, fire the middle daughter, lake the youngest. You do not need to memorize this list, but it colours the old texts: where thunder and wind meet, an eldest son and an eldest daughter meet as well, and that says something about duration and commitment.

Trigrams in your reading

When you consult the oracle, you build your hexagram line by line, from the bottom up. After three lines your inner trigram is already standing: a first image of where you are inwardly. Working with real yarrow stalks, you feel that build-up most strongly: each line takes time, and the hexagram grows under your hands. It works just as well digitally: cast the stalks online and watch your hexagram appear from the bottom up.

Once you have your hexagram, look at the two images before you read the text. Ask yourself what is inside and what is outside. Is the water within (the emotion, the danger in yourself) or without (the circumstances)? Does the mountain rest above (outward stillness) or below (inner stillness)? Often that single question tells you half the interpretation, and you read the rest not as strange poetry, but as the working-out of something you had already seen yourself.

Frequently asked questions

What are the eight trigrams of the I Ching?

The eight trigrams are figures of three lines, each yang or yin, that together form eight images from nature: heaven, earth, thunder, water, mountain, wind, fire and lake. Stacking two trigrams produces a hexagram; that is how all sixty-four hexagrams of the I Ching are formed.

What is the difference between the inner and the outer trigram?

The inner trigram is the lower half of a hexagram and describes your inner attitude, what happens beneath the surface. The outer trigram is the upper half and shows how the situation expresses itself outwardly and what your surroundings ask of you.

How many hexagrams can you form with eight trigrams?

Exactly sixty-four: eight possibilities for the inner trigram times eight for the outer one. Every hexagram in the I Ching is therefore a unique combination of two images from nature.

Why do the trigrams have family roles?

Tradition sees heaven and earth as father and mother, and the six other trigrams as their sons and daughters. These roles make the images human and colour the interpretations: a meeting between two trigrams is also a meeting between two characters.