易經卦爻Yijing: Trigrams, Hexagrams and Lines

由陰陽兩種爻畫組成的六十四個卦象，配上簡短古奧的卦爻辭，構成了《易經》（《周易》）的核心。它是儒家「五經」之首，既是一部古老的占筮書，也是中國哲學的重要經典。本頁介紹它的符號結構、文本層次和占筮方法的歷史，並附六十四卦一覽表。Sixty-four hexagrams composed of two kinds of line, yin and yang, together with their brief and archaic hexagram and line statements, form the core of the Yijing (I Ching, Book of Changes; also called the Zhouyi, Changes of Zhou). First of the Confucian “Five Classics”, it is both an ancient divination manual and a major classic of Chinese philosophy. This page introduces its symbolic structure, textual layers and the history of its divination methods, with a table of all sixty-four hexagrams.

《周易》是一本怎樣的書What Kind of Book Is the Zhouyi?

今本《周易》分為兩部分：The received Zhouyi has two parts:

• 經：六十四卦的卦畫、卦名、卦辭和爻辭，一般認為主體形成於西周時期，原是占筮用書。The Classic (jing): The figures, names, hexagram statements and line statements of the sixty-four hexagrams, generally thought to have taken shape mainly in the Western Zhou; originally a manual for divination.
• 傳：解釋經文的十篇文字，合稱「十翼」：〈彖傳〉上下、〈象傳〉上下、〈繫辭傳〉上下、〈文言傳〉、〈說卦傳〉、〈序卦傳〉、〈雜卦傳〉。大致成於戰國至漢初。The Commentaries (zhuan): Ten texts explaining the Classic, together called the “Ten Wings”: the Tuanzhuan (Commentary on the Judgements, parts 1 and 2), the Xiangzhuan (Commentary on the Images, parts 1 and 2), the Xici zhuan (Appended Statements, parts 1 and 2), the Wenyan (Words of the Text), the Shuogua (Discussion of the Trigrams), the Xugua (Sequence of the Hexagrams) and the Zagua (Miscellaneous Notes on the Hexagrams). They date roughly from the Warring States to the early Han.

傳統說法是「伏羲畫八卦，文王重為六十四卦並作卦辭，周公作爻辭，孔子作十翼」，即所謂「人更三聖，世歷三古」。現代學者大多認為經文並非出自一人一時，十翼也不是孔子親撰，而是戰國以來儒家學者陸續寫成的。漢代以後，《易》學分為側重符號與數理的「象數派」和側重義理的「義理派」。前者以漢代京房、孟喜等為代表，後者以魏晉王弼、宋代程頤為代表；南宋朱熹則強調「易本為卜筮而作」，兼重兩者。The traditional account is that “Fuxi drew the eight trigrams, King Wen doubled them into sixty-four hexagrams and wrote the hexagram statements, the Duke of Zhou wrote the line statements, and Confucius wrote the Ten Wings” — the so-called “three sages over three ages of antiquity”. Most modern scholars hold that the Classic was not the work of one person or one time, and that the Ten Wings were not written by Confucius himself but by Confucian scholars from the Warring States onwards. After the Han, Yijing studies divided into the “image and number” school (xiangshu), focusing on symbols and numerology, and the “meaning and principle” school (yili), focusing on philosophical meaning. The former is represented by Jing Fang and Meng Xi of the Han, the latter by Wang Bi of the Wei–Jin and Cheng Yi of the Song; the Southern Song Zhu Xi stressed that “the Changes was originally made for divination” and valued both.

八卦The Eight Trigrams

八卦由三條爻組成，每爻非陰即陽，共 2³ = 8 種組合。據〈說卦傳〉，八卦各有象徵：A trigram consists of three lines, each either yin or yang, giving 2³ = 8 combinations. According to the Shuogua, each trigram has its symbolism:

八卦的排列有「先天」與「後天」兩種。後天八卦（又稱文王八卦）方位見於〈說卦傳〉「帝出乎震」一章，也是奇門遁甲、風水所用的方位系統。先天八卦（又稱伏羲八卦，乾南坤北）的圖式則是宋代邵雍等人根據〈說卦傳〉「天地定位」一章整理而成，所謂「伏羲」所作只是傳統說法。There are two arrangements of the eight trigrams, “Former Heaven” and “Later Heaven”. The Later Heaven arrangement (also called King Wen’s arrangement) appears in the Shuogua chapter beginning “The Lord comes forth in Zhen”, and is also the directional system used in Qimen Dunjia and fengshui. The Former Heaven arrangement (also called Fuxi’s arrangement, with Qian in the south and Kun in the north) was systematised by Shao Yong and others in the Song on the basis of the Shuogua chapter beginning “Heaven and Earth establish their positions”; its attribution to Fuxi is only traditional.

爻的概念The Concept of the Line

「爻」是構成卦的基本線條。連續的一畫「⚊」為陽爻，中斷的一畫「⚋」為陰爻。〈繫辭傳〉說：「爻也者，效天下之動者也。」The line (yao) is the basic stroke from which hexagrams are built. An unbroken line “⚊” is a yang line; a broken line “⚋” is a yin line. The Xici says: “The lines are what imitate the movements of all under heaven.”

• 爻位：六爻由下而上數，依次稱為初、二、三、四、五、上。Line positions: The six lines are counted from the bottom up, called first, second, third, fourth, fifth and top.
• 爻題：陽爻稱「九」，陰爻稱「六」。所以乾卦第一爻稱「初九」，坤卦最上一爻稱「上六」。Line labels: A yang line is called “nine” and a yin line “six”. Thus the first line of Qian is called “nine at the beginning” (chujiu) and the top line of Kun “six at the top” (shangliu).
• 老與少：占筮所得的數字有 6、7、8、9 四種。7 為少陽、8 為少陰，屬「不變之爻」；9 為老陽、6 為老陰，屬「變爻」，即陽極轉陰、陰極轉陽。爻題用「九」「六」，正是因為《易》以變化為重。Old and young: Divination yields one of four numbers: 6, 7, 8 or 9. Seven is young yang and 8 young yin, the “unchanging lines”; 9 is old yang and 6 old yin, the “changing lines”, in which yang at its extreme turns to yin and yin at its extreme to yang. The line labels use “nine” and “six” precisely because the Changes gives priority to change.
• 當位、得中、相應：傳統解易認為，陽爻居奇數位（初、三、五）、陰爻居偶數位（二、四、上）為「當位」；二、五兩爻位於下卦和上卦的正中，稱為「得中」；初與四、二與五、三與上，一陰一陽則為「相應」。Proper position, centrality and correspondence: Traditional interpretation holds that a yang line in an odd position (first, third, fifth) or a yin line in an even position (second, fourth, top) is “in its proper place”; the second and fifth lines, at the centre of the lower and upper trigrams, are “central”; and the first and fourth, second and fifth, and third and top lines “correspond” when one is yin and the other yang.

六十四卦的結構The Structure of the Sixty-Four Hexagrams

兩個八卦上下相疊，得到 8 × 8 = 64 個六爻卦（2⁶ = 64）。下方的稱下卦（內卦），上方的稱上卦（外卦）。例如上卦為坎（水）、下卦為震（雷）的卦名為「屯」，全稱「水雷屯」。Stacking two trigrams one above the other gives 8 × 8 = 64 six-line hexagrams (2⁶ = 64). The bottom one is the lower (inner) trigram and the top one the upper (outer) trigram. For example, the hexagram with Kan (Water) above and Zhen (Thunder) below is named Zhun (“Difficulty at the Beginning”), in full “Water over Thunder, Zhun”.

今本卦序（通稱「文王卦序」）有一個明顯規律：六十四卦兩兩成對，後一卦多為前一卦上下顛倒（稱「覆」或「綜」），若某卦顛倒後不變（如乾、坤、坎、離、頤、大過、中孚、小過），則與其陰陽全反的卦配對（稱「變」或「錯」）。〈序卦傳〉則嘗試以義理解釋卦與卦的先後關係。另外，宋代邵雍有按二進制規律排列的「先天六十四卦次序」；德國哲學家萊布尼茲在 1703 年收到耶穌會士白晉（Joachim Bouvet）從中國寄來的此圖，注意到它與自己的二進制算術相符。The received order (commonly called the “King Wen sequence”) shows a clear pattern: the sixty-four hexagrams form thirty-two pairs, the second of each pair usually being the first turned upside down (called “inversion”, fu or zong); where a hexagram is unchanged when inverted (Qian, Kun, Kan, Li, Yi, Daguo, Zhongfu, Xiaoguo), it is paired with the hexagram whose every line is reversed (called “conversion”, bian or cuo). The Xugua tries to explain the order of the hexagrams in terms of meaning. In addition, Shao Yong of the Song arranged the “Former Heaven sequence of the sixty-four hexagrams” according to a binary pattern; in 1703 the German philosopher Leibniz received this diagram from the Jesuit Joachim Bouvet in China and noted that it matched his own binary arithmetic.

卦辭與爻辭Hexagram and Line Statements

每卦有一段卦辭（又稱彖辭），總論全卦；每爻有一條爻辭，共 64 × 6 = 384 條；乾、坤兩卦另各有一條「用九」「用六」，所以合共 386 條。以乾卦為例：Each hexagram has a hexagram statement (also called the “judgement”, tuanci) summarising the whole; each line has a line statement, 64 × 6 = 384 in all; Qian and Kun each have one extra statement, “using nines” and “using sixes”, making 386 altogether. Taking Qian as an example:

• 卦辭：「元亨利貞。」Hexagram statement: “Origination, prevalence, benefit, steadfastness” (yuan heng li zhen).
• 初九：「潛龍勿用。」Nine at the beginning: “Hidden dragon. Do not act.”
• 九二：「見龍在田，利見大人。」Nine in the second place: “Dragon appearing in the field. It is beneficial to see the great man.”
• 九五：「飛龍在天，利見大人。」Nine in the fifth place: “Flying dragon in the heavens. It is beneficial to see the great man.”
• 上九：「亢龍有悔。」Nine at the top: “Arrogant dragon will have cause to repent.”
• 用九：「見群龍無首，吉。」Using nines: “A flight of dragons without heads appears. Auspicious.”

卦爻辭的語言古奧，常用「吉、凶、悔、吝、无咎、利貞」等占斷用語，也夾雜不少可能反映商周歷史的記載（例如「帝乙歸妹」「高宗伐鬼方」）。「元亨利貞」四字，傳統（如〈文言傳〉）解作四種德性，而現代學者如高亨等則多從占筮語言理解，例如把「貞」解作「占問」。The language of the statements is archaic, often using divinatory formulas such as “auspicious, ominous, regret, distress, no blame, beneficial to be steadfast”, and includes a number of passages that may reflect Shang–Zhou history (for example “Di Yi gives his younger sister in marriage” and “Gaozong attacked the Guifang”). The four words yuan heng li zhen were traditionally (as in the Wenyan) interpreted as four virtues, whereas modern scholars such as Gao Heng mostly understand them as divinatory language, for instance reading zhen as “to divine”.

占筮方法的歷史History of Divination Methods

大衍筮法（蓍草法）The Dayan method (yarrow stalks)

最古老而有文獻依據的方法，見於〈繫辭傳上〉：「大衍之數五十，其用四十有九。分而為二以象兩，掛一以象三，揲之以四以象四時，歸奇於扐以象閏……」按這段記載，大意是用五十根蓍草，取出一根不用，餘下四十九根經「分二、掛一、揲四、歸奇」四個步驟為「一變」，三變得出一爻，十八變得出一卦。所得數字為 6、7、8、9 之一。The oldest method with textual support is found in the Xici, part 1: “The number of the Great Expansion is fifty, of which forty-nine are used. They are divided into two to represent the two; one is hung up to represent the three; they are counted off in fours to represent the four seasons; the remainder is put between the fingers to represent the intercalary month…” According to this passage, the gist is that fifty yarrow stalks are used, one is set aside, and the remaining forty-nine go through four operations — dividing in two, hanging one, counting off in fours and returning the remainder — to make “one change”; three changes produce one line and eighteen changes a hexagram. The result is one of the numbers 6, 7, 8 or 9.

〈繫辭傳〉原文較簡略，後世的具體操作主要依據朱熹《周易本義》前附的〈筮儀〉和《易學啟蒙》的整理。用此法得到各數的概率並不相等：老陰（6）約 1/16，少陽（7）約 5/16，少陰（8）約 7/16，老陽（9）約 3/16。The Xici text is rather terse; later concrete practice relied mainly on the “Divination Procedure” prefaced to Zhu Xi’s Zhouyi benyi (Original Meaning of the Zhouyi) and his systematisation in the Yixue qimeng (Introduction to the Study of the Changes). The probabilities of the numbers under this method are unequal: old yin (6) about 1/16, young yang (7) about 5/16, young yin (8) about 7/16, old yang (9) about 3/16.

《左傳》和《國語》記載了二十多則春秋時期的筮例，是研究早期《易》占實際應用的重要資料。The Zuozhuan and Guoyu record more than twenty cases of divination from the Spring and Autumn period, important material for studying how the Changes was actually used in early times.

金錢卦（擲錢法）The coin method

傳統做法是以三枚銅錢代替蓍草，每次擲出後按正反面數目定為 6、7、8、9 之一，擲六次由下而上得出一卦。此法較為簡便，唐宋以後在民間廣為流行。傳統上把此法歸於漢代京房，宋代流傳的《火珠林》一書即以擲錢配合「納甲」（把天干地支配入卦爻）來斷事，但其確切起源年代學界仍有不同意見。金錢卦得出 6、7、8、9 的概率分別為 1/8、3/8、3/8、1/8，與蓍草法不同。Traditionally, three bronze coins replace the yarrow stalks; after each toss, the number of heads and tails determines one of 6, 7, 8 or 9, and six tosses from the bottom up produce a hexagram. This simpler method became widespread among the populace after the Tang and Song. It is traditionally attributed to Jing Fang of the Han, and the Huozhulin, circulating in the Song, combined coin tossing with najia (assigning heavenly stems and earthly branches to the lines) to judge affairs, though scholars still disagree about its exact date of origin. The coin method yields 6, 7, 8 and 9 with probabilities of 1/8, 3/8, 3/8 and 1/8 respectively, different from the yarrow-stalk method.

其他Others

宋代以後還有以數字、時間起卦的「梅花易數」（託名邵雍）等方法，屬於後起的發展。From the Song onwards there were also methods such as the “Plum Blossom Numerology” (Meihua yishu, attributed to Shao Yong), which casts hexagrams from numbers and times — later developments.

出土文獻與現代研究Excavated Texts and Modern Research

• 數字卦：商周甲骨、青銅器和陶器上發現以數字組成的符號，學者（如張政烺）認為是早期筮占的記錄，可能是卦畫的前身。Numerical trigrams/hexagrams: Symbols composed of numbers found on Shang–Zhou oracle bones, bronzes and pottery are regarded by scholars (such as Zhang Zhenglang) as records of early milfoil divination, possibly the precursors of the line figures.
• 馬王堆帛書《周易》：1973 年在湖南長沙馬王堆三號漢墓（下葬於公元前 168 年）出土，卦序與今本不同，並附有今本所無的易傳。The Mawangdui silk manuscript Zhouyi: Excavated in 1973 from Han Tomb No. 3 at Mawangdui, Changsha, Hunan (buried in 168 BCE), its hexagram order differs from the received text, and it includes commentaries not found in the received version.
• 上博簡《周易》：上海博物館藏戰國楚竹書，2003 年公佈，是目前所見最早的《周易》文本之一。The Shanghai Museum Zhouyi: Warring States Chu bamboo slips held by the Shanghai Museum, published in 2003; one of the earliest Zhouyi texts known.
• 清華簡《筮法》：清華大學藏戰國竹簡，2013 年公佈，展示了與《周易》不同的戰國占筮體系。The Tsinghua slips Shifa (Divination Methods): Warring States bamboo slips held by Tsinghua University, published in 2013, revealing a Warring States divination system different from the Zhouyi.

六十四卦一覽表Table of the Sixty-Four Hexagrams

按今本（文王）卦序排列。全稱的讀法是「上卦之象＋下卦之象＋卦名」；上下卦相同者稱「某為某」。卦象符號使用 Unicode 易經六十四卦字元，如裝置字型不支援，可能顯示為方格。Arranged in the received (King Wen) order. The full name reads “image of upper trigram + image of lower trigram + hexagram name”; where the two trigrams are the same, it is called “X doubled”. The hexagram symbols use the Unicode Yijing hexagram characters; if your device’s fonts do not support them, they may appear as boxes.

參考資料References

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