Yijian · Understand the I Ching at your own pace Free learning · No sign-in required
Yijian

Eight Introductory Lessons / 03

The Sixty-Four Hexagrams and the Primary Hexagram

Eight lower trigrams times eight upper trigrams make sixty-four. The one you arrive at is called the primary hexagram.

Eight times eight is sixty-four

The previous lesson split six lines into two trigrams. The lower trigram has eight possibilities and so does the upper one. Combine them freely and you get 8 × 8 = 64.

Count it the other way and you reach the same place: six lines, each either yin or yang, is 2 to the sixth power, which is 64. Two routes, one number, because they describe the same thing.

Sixty-four is not an auspicious number someone picked. It is what you get when the arrangements are exhausted. It also means there is no sixty-fifth hexagram.

Build any hexagram

Eight trigrams paired two at a time give exactly sixty-four combinations — no more, no fewer — so any arrangement of six lines is one of the sixty-four. To identify one, read the lower three lines as a trigram, then the upper three: Qian ☰ below and Kun ☷ above is hexagram 11, Tai; swap them, Kun ☷ below and Qian ☰ above, and you get hexagram 12, Pi, a different hexagram.

What "primary hexagram" means

The primary hexagram is simply the six lines in front of you, exactly as they stand. It is also called the original hexagram.

The term exists because there will later be a second hexagram, the one that appears after change is applied. To keep the two apart, the first is named the primary. Before change enters the picture, the primary hexagram is just the hexagram, with no extra meaning.

Reading usually starts here: which hexagram is it, what are its two halves, and what does its judgement text say.

Numbering and names

In the received edition the sixty-four hexagrams follow a fixed sequence, beginning with 1 Qian and 2 Kun and ending with 63 Jiji and 64 Weiji. That order is an inherited editorial arrangement rather than something derived from yin and yang, so there is no particular merit in memorising the numbers. Being able to look them up is enough.

Each hexagram has a name — Zhun, Meng, Xu, Song, and so on. Most names are a single character taken from a keyword in the judgement text or from traditional usage, and serve as a label for that hexagram.

The hexagram library in this app lets you find a hexagram from its two trigrams, so there is nothing to memorise.

One more thing worth knowing up front: the sixty-four hexagrams are on an equal footing, and none of them is inherently better or worse than another. Some names sound uncomfortable — Oppression, Obstruction, Splitting Apart — but they describe a situation rather than pass a verdict on you, and a pleasant-sounding name guarantees nothing either.

Where this app marks a tendency for a hexagram, that is the writer's interpretation after reading its text. The reasoning is stated, and it remains an interpretation.

Try it yourself

This lesson has a hands-on exercise. It is built into the Traditional Chinese lesson page, where you can try it straight away: open the interactive exercise.

Quick Quiz

Where does the number sixty-four come from?
  • Eight lower trigrams times eight upper trigrams, 8 × 8.
  • The trigrams added together, 8 + 8 + …
  • Sixty-four common ones were selected from a larger set.
View answers and explanations for every option

Eight lower trigrams paired with eight upper trigrams: 8×8. (Correct) : Correct. Equivalently, six lines each have two yin/yang possibilities: 2 to the sixth power is also 64.

The trigrams added together, 8 + 8 + … : Multiply rather than add. Every lower trigram can pair with all eight upper trigrams, giving 8×8.

Sixty-four common ones were selected from a larger set. : No hexagrams were discarded. Six lines have exactly 64 arrangements, all included.

What does "primary hexagram" refer to?
  • The six lines as they stand, before any change is applied.
  • The single most fundamental hexagram, namely Qian.
  • The new hexagram you get after change.
View answers and explanations for every option

The present six-line arrangement, before any changes are applied. (Correct) : Correct. It is called the “original” hexagram to distinguish it from the one after change.

The single most fundamental hexagram, namely Qian. : The original hexagram is not one fixed hexagram. Whichever you construct is your original hexagram.

The new hexagram you get after change. : That is the resulting hexagram, covered in Lesson Five. The original is the one before change.

Kun ☷ below and Qian ☰ above — is that enough to identify a single hexagram?
  • Yes. Once both halves are fixed, all six lines are fixed.
  • No, you also need the hexagram number.
  • No, you also need to know which line changes.
View answers and explanations for every option

Yes. Once both halves are fixed, all six lines are fixed. (Correct) : Correct. Three lower lines and three upper lines fill all six positions. Kun below and Qian above form Hexagram 12, Pi; reversing them to Qian below and Kun above gives Hexagram 11, Tai.

No, you also need the hexagram number. : The hexagram number is a lookup result, not another input. Once the six lines are fixed, the number is fixed too.

No, you also need to know which line changes. : Changing lines affect the resulting hexagram, not the identity of the original.

Back to Lessons Next Lesson →