The sixty-four hexagrams

Six binary digits,
and three thousand years.

Every figure in the Yijing is six lines that are each one of two things. That is enough to say a great deal about the book before opening it — including the fact that there are sixty-four of them, and why the number could not have been anything else.

The eight, then the sixty-four

Three lines, two states each, gives eight trigrams. Six lines gives sixty-four hexagrams, and every hexagram is exactly one pair of trigrams: an upper and a lower, with no remainder and no leftovers. Eight times eight is sixty-four, and the grid below is that multiplication drawn out.

The eight trigrams in Unicode order, which is also their binary order: read the lines bottom-first as bits with solid for one, and the last column counts 7 down to 0. The phase column is the wuxing assignment — the Chinese five, not the four elements the zodiac pages on this site use.
NameChineseImageAttributePhaseLines, bottom firstAs bits
qiánheavenforcemetalsolid, solid, solid111 = 7
duìlakeopenmetalsolid, solid, broken011 = 3
fireradiancefiresolid, broken, solid101 = 5
zhènthundershakewoodsolid, broken, broken001 = 1
xùnwindgroundwoodbroken, solid, solid110 = 6
kǎnwatergorgewaterbroken, solid, broken010 = 2
gènmountainboundearthbroken, broken, solid100 = 4
kūnearthfieldearthbroken, broken, broken000 = 0
The sixty-four hexagrams as upper trigram against lower trigramAn eight by eight matrix. Each row is one upper trigram, each column one lower trigram, and each cell holds the hexagram the two make together with its King Wen number. The eight hexagrams built from a doubled trigram fall on the diagonal.heavenheavenlakelakefirefirethunderthunderwindwindwaterwatermountainmountainearthearth11013254463312435849172847314514383021506456353454555132406216961374257595320560633482939826412227184522311193624467152
Every hexagram, arranged by the trigram above it and the trigram below it. Each row is one upper trigram and each column one lower trigram, so every cell is a different pair and no pair is missing. The eight figures built from a doubled trigram sit on the diagonal — those are hexagrams 1, 2, 29, 30, 51, 52, 57 and 58.

Read a row and the top half of every figure stays the same while the bottom half runs through all eight possibilities. That is the entire construction of the book's vocabulary, and it is visible without knowing a word of Chinese.

The King Wen order, and the rule hiding in it

The numbering above is the King Wen sequence, the order of the received text and the order the Unicode characters ䷀ to ䷿ are assigned in. Nobody has satisfactorily explained why it is in that order — it is not the binary order, it is not alphabetical in any sense, and the arrangement has been argued about for centuries.

But it is not arbitrary either, and there is one rule that holds without a single exception. Take any odd-numbered hexagram and its even-numbered partner:

That rule fixes all thirty-two pairs, and a single hexagram out of place would break it. It is also, conveniently, a test: this site's version of the table is checked against that rule automatically, along with three other structural properties, on every build. The sixty-four figures here were not typed out from a book — they were derived from the Unicode characters and then made to prove themselves.

The binary story, told accurately

In the eleventh century the Song scholar Shao Yong set out an arrangement of the sixty-four that is not the King Wen order at all. In it, reading each figure as six bits with the bottom line least significant, the sequence counts straight from 0 to 63.

The Fu Xi arrangement: sixty-four hexagrams in binary orderSixty-four hexagrams around a ring, starting at the top with six broken lines and running clockwise, each rotated so its bottom line faces the centre. Read every figure as six bits with a solid line for one and a broken line for zero and the sequence counts from zero to sixty-three exactly once. The ring is banded into eight sectors; the eight figures in each share one upper trigram, marked outside the ring.0 → 63solid = 1 · broken = 0bottom line is least significanteach band of eight shares an upper trigram
The Fu Xi arrangement as a ring, 0 at the top running clockwise to 63. Every figure faces the centre, bottom line innermost. Read solid as 1 and broken as 0 and you can count the whole circle — which is the only reason to put it on a page.
The same sixty-four in binary order, as an eight by eight squareThe Fu Xi sequence laid out in rows of eight, reading left to right and top to bottom, from zero in the corner to sixty-three.
The same sixty-four as a square, eight rows of eight, left to right and top to bottom. Zero is the top-left corner, sixty-three the bottom-right. The circle and the square were traditionally drawn as a pair.

In 1701 the Jesuit missionary Joachim Bouvet, in Beijing, sent a copy of this diagram to Gottfried Wilhelm Leibniz, who had been working on binary arithmetic for years and published his paper on it in 1703. Leibniz recognised his own notation in the drawing and was delighted by it — he read it as evidence that an ancient civilisation had arrived at the same idea.

Here is the part usually left out. The Fu Xi order is binary counting from 0 to 63; that much is simply true and the circle above lets anyone verify it. But nobody in China was doing arithmetic with it. There is no evidence of anyone adding, carrying or multiplying hexagrams. Shao Yong's arrangement is a complete and systematic enumeration, which is a real and impressive thing, and it is a different thing from a number system. The popular version — "the Chinese invented binary" — overstates a fact that is interesting enough without the help.

How old any of this actually is

The book has layers, and they are separated by centuries.

None of that diminishes the book. A three-thousand-year-old text with a two-thousand-year-old commentary tradition does not need a legendary author to be remarkable, and the dates are checkable in a way the legends are not — which is the same reason this site dates the moon-phase soulmate claim to 2022 and rune divination to 1982.

All sixty-four

The characters below are real Unicode: ䷀ through ䷿, block U+4DC0 to U+4DFF, in King Wen order. The line diagram beside each one is drawn from that character's own composition rather than from the glyph, which is why the two always agree.

All sixty-four in King Wen order — the sequence of the received text, and the order of the Unicode block these characters come from. The last column is written for this site and is not a translation of anything.
#LinesNameChineseUpper over lowerIn our words
1The Creative Heaven乾 qián☰ heaven / ☰ heavenPure initiative, six lines of it, with nothing to push against and nobody to ask.
2The Receptive Earth坤 kūn☷ earth / ☷ earthPure receptivity: the ground that takes whatever is put on it and makes it grow, which is not the same as passivity.
3Difficulty At The Beginning屯 zhūn☵ water / ☳ thunderThunder under water — the first push, before it has worked out which way is up.
4Youthful Folly蒙 méng☶ mountain / ☵ waterNot knowing, and not yet knowing that you do not know. The one condition teaching can actually fix.
5Waiting需 xū☵ water / ☰ heavenStrength held back by an obstacle it could break and should not. Waiting as a decision rather than a delay.
6Conflict訟 sòng☰ heaven / ☵ waterWater sinking, heaven rising: two parts of one situation moving apart, which is what an argument actually is.
7The Army師 shī☷ earth / ☵ waterOne person answerable for many. Discipline that has to be organised because it will not arise.
8Holding Together比 bǐ☵ water / ☷ earthWater over earth, going where the ground allows. Alliance formed by proximity rather than by choice.
9Small Taming小畜 xiǎo xù☴ wind / ☰ heavenA restraint too light to stop anything, applied anyway. The pause before, not the barrier.
10Treading履 lǚ☰ heaven / ☱ lakeWalking carefully across something that could turn. Conduct as footing.
11Peace泰 tài☷ earth / ☰ heavenEarth above, heaven below, the two moving towards each other. The rare arrangement where everything is going the right way.
12Standstill否 pǐ☰ heaven / ☷ earthThe same two, moving apart. Nothing is wrong and nothing is meeting.
13Fellowship同人 tóng rén☰ heaven / ☲ fireFire under heaven, rising towards it. People joined by what they are looking at rather than by where they are.
14Great Possession大有 dà yǒu☲ fire / ☰ heavenFire above heaven: everything visible at once, and the difficulty of holding it.
15Modesty謙 qiān☷ earth / ☶ mountainA mountain inside the earth. Height that does not announce itself, which is the only kind that lasts.
16Enthusiasm豫 yù☳ thunder / ☷ earthThunder coming out of the ground. Readiness that spreads before anybody has decided anything.
17Following隨 suí☱ lake / ☳ thunderGoing with rather than after. What the figure leaves open is who is choosing.
18Work On The Decayed蠱 gǔ☶ mountain / ☴ windSomething has been quietly rotting while nobody looked. The work here is not building; it is repair.
19Approach臨 lín☷ earth / ☱ lakeComing near to something larger, deliberately, while there is still time to.
20Contemplation觀 guān☴ wind / ☷ earthWind over earth: looking at the whole thing from far enough away to see its shape.
21Biting Through噬嗑 shì kè☲ fire / ☳ thunderAn obstruction between the teeth. It does not dissolve; it has to be bitten.
22Grace賁 bì☶ mountain / ☲ fireFire at the foot of a mountain, lighting the surface. Ornament, honestly named as ornament.
23Splitting Apart剝 bō☶ mountain / ☷ earthThe ground giving way under a mountain. Decay that has reached the load-bearing part.
24Return復 fù☷ earth / ☳ thunderOne yang line at the bottom after five yin. The turn, at the moment it becomes possible and before it is visible.
25Innocence无妄 wú wàng☰ heaven / ☳ thunderActing without calculation. Not naivety — the absence of an angle.
26Great Taming大畜 dà xù☶ mountain / ☰ heavenHeaven held inside a mountain. Enormous force under an equally large restraint, which is what accumulation is.
27Mouth Corners頤 yí☶ mountain / ☳ thunderThe shape of an open mouth. What you take in and what you say, treated as one question.
28Great Preponderance大過 dà guò☱ lake / ☴ windA beam too heavy at the middle. Something is bearing more than its structure allows.
29The Abysmal Water坎 kǎn☵ water / ☵ waterWater doubled: a pit inside a pit. Danger that is repeating rather than passing.
30The Clinging Fire離 lí☲ fire / ☲ fireFire doubled. It has no substance of its own and burns only by holding on to something else.
31Influence咸 xián☱ lake / ☶ mountainA lake on a mountain. Attraction as a physical fact, before anybody has interpreted it.
32Duration恆 héng☳ thunder / ☴ windThunder and wind, which never occur apart. Constancy as a pattern that keeps repeating, not as a thing standing still.
33Retreat遯 dùn☰ heaven / ☶ mountainA mountain under heaven, and heaven going on rising. Withdrawing while withdrawal is still a choice rather than a rout.
34Great Power大壯 dà zhuàng☳ thunder / ☰ heavenThunder above heaven. More force than the situation requires, which is its own problem.
35Progress晉 jìn☲ fire / ☷ earthThe sun rising over the earth. Advance that is simply happening, at its own rate.
36Darkening Of The Light明夷 míng yí☷ earth / ☲ fireThe sun gone under the earth. The light still exists; it is a question of where you are standing.
37The Family家人 jiā rén☴ wind / ☲ fireWind coming out of fire. Roles that exist only in relation to each other.
38Opposition睽 kuí☲ fire / ☱ lakeFire rising, lake sinking. Two things whose natures move them apart while both stay in the room.
39Obstruction蹇 jiǎn☵ water / ☶ mountainWater on a mountain: the hard way, uphill. The counsel here is about direction rather than effort.
40Deliverance解 jiě☳ thunder / ☵ waterThunder and rain, and the tension breaks. The relief after, not the escape from.
41Decrease損 sǔn☶ mountain / ☱ lakeTaking from below to add above. A loss that is deliberate and is not therefore painless.
42Increase益 yì☴ wind / ☳ thunderThe same movement reversed. Something is being given downward.
43Breakthrough夬 guài☱ lake / ☰ heavenFive yang lines and one yin at the top. The last of something, and the decision to say so out loud.
44Coming To Meet姤 gòu☰ heaven / ☴ windOne yin line arriving under five yang. Small, unplanned, and the beginning of the whole cycle turning.
45Gathering Together萃 cuì☱ lake / ☷ earthA lake over the earth: things collecting because the ground holds them.
46Pushing Upward升 shēng☷ earth / ☴ windWood growing inside the earth. Progress that is invisible while it is happening.
47Oppression困 kùn☱ lake / ☵ waterA lake with its water drained away below. Exhaustion — resources present and out of reach.
48The Well井 jǐng☵ water / ☴ windThe well does not move and does not empty. What changes is whether anyone comes with a bucket.
49Revolution革 gé☱ lake / ☲ fireFire in a lake: two elements that destroy each other. Change by replacement, not by adjustment.
50The Cauldron鼎 dǐng☲ fire / ☴ windThe vessel that transforms what is put in it — the counterpart to the figure before: change by cooking rather than by burning.
51The Arousing Thunder震 zhèn☳ thunder / ☳ thunderThunder doubled. The shock, and then the second one that shows whether the first was heard.
52The Keeping Still Mountain艮 gèn☶ mountain / ☶ mountainMountain doubled. Stopping — not resting, stopping.
53Development漸 jiàn☴ wind / ☶ mountainA tree on a mountain, growing slowly because there is nowhere else to grow. Gradual by necessity.
54The Marrying Maiden歸妹 guī mèi☳ thunder / ☱ lakeEntering a situation in a position you did not choose and cannot immediately change.
55Abundance豐 fēng☳ thunder / ☲ fireThunder and lightning together: everything at maximum. The figure is unusually direct that maximum does not last.
56The Wanderer旅 lǚ☲ fire / ☶ mountainFire on a mountain, moving on. Everything you have is with you and none of it is yours.
57The Gentle Wind巽 xùn☴ wind / ☴ windWind doubled: penetration by persistence rather than by force. It gets in everywhere and moves nothing at once.
58The Joyous Lake兌 duì☱ lake / ☱ lakeLake doubled — two open surfaces reflecting each other. Pleasure, and the shallowness that is its risk.
59Dispersion渙 huàn☴ wind / ☵ waterWind over water, breaking it up. Dissolving something that had hardened.
60Limitation節 jié☵ water / ☱ lakeWater in a lake: the container is what makes the water usable. A limit as the thing that gives a shape.
61Inner Truth中孚 zhōng fú☴ wind / ☱ lakeTwo solid lines outside, two yielding within. Sincerity described structurally: the same inside as out.
62Small Preponderance小過 xiǎo guò☳ thunder / ☶ mountainSlightly too much of something small. The figure about the difference between a small mistake and a large one.
63After Completion既濟 jì jì☵ water / ☲ fireEvery line in its correct place — the only perfectly ordered figure, and therefore the only one whose sole direction is out of order.
64䷿Before Completion未濟 wèi jì☲ fire / ☵ waterEvery line in the wrong place, and the book ends here rather than on the finished one.
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