Zhouyi vs. I Ching: What Is the Difference?
The short answer first
When people today say the Zhouyi (周易) and when they say the I Ching (易经, Yijing), they usually mean the same book, and there is no need to split hairs. If you do want to draw a line, the difference lies in two words, jing (经, "classic") and zhuan (传, "commentary"): the book is made of two layers of text, the earlier layer being the classic and the later layer the commentaries. The name "I Ching" sometimes refers only to the first layer and sometimes to the whole book, which is why it is easy to get confused.
Classic and commentaries
The classic consists of the figures and names of the sixty-four hexagrams, the sixty-four judgments and the three hundred and eighty-four line statements, plus "All nines" and "All sixes" for the two hexagrams Qian (Heaven) and Kun (Earth). It was originally a book for yarrow-stalk divination, its language is terse and archaic, and it is generally held to date from the Western Zhou. The word Zhou (周) in the title is usually taken to mean the Zhou dynasty, though some read it as "all-encompassing".
The commentaries are seven works in ten parts, written by later hands to explain the classic and traditionally called the Ten Wings (十翼, Shi Yi); a wing here is something that assists. Tradition ascribes them to Confucius. Doubts have been raised ever since Ouyang Xiu in the Northern Song, and today they are generally held to date from the Warring States period to the early Han, and not to be the work of one person or one time.
| Commentary | Parts | What it covers |
|---|---|---|
| Tuanzhuan (the Tuan commentary) | Two parts | Explains the hexagram name and the judgment |
| Xiangzhuan (the Image commentary) | Two parts | The Image (Daxiang) speaks of the images of the upper and lower trigrams and of what the noble one should model on them; the small Image commentary (Xiaoxiang) explains the line statements one by one |
| Xici (the "Great Commentary") | Two parts | A general discussion of the principles of the Changes; it also records the yarrow-stalk method |
| Wenyan ("Commentary on the Words of the Text") | One part | Devoted to the two hexagrams Qian (Heaven) and Kun (Earth) |
| Shuogua ("Discussion of the Trigrams") | One part | The images that each of the eight trigrams stands for |
| Xugua ("Sequence of the Hexagrams") | One part | Why the sixty-four hexagrams are arranged in this order |
| Zagua ("Miscellaneous Notes on the Hexagrams") | One part | Sets the hexagrams against each other in pairs and sums up each in a word or two |
Many famous lines that people assume come from "the original text of the I Ching" are in fact from the commentaries. The judgment of Qian (Heaven) is just four characters, yuan heng li zhen (元亨利贞, "Great success. It is favorable to stay true."), and that is the classic. "Heaven moves with vigor. The noble one grows ever stronger through unceasing effort" is from the Image commentary, which is far later. The editions in common use today break up the Tuan and Image commentaries and attach the pieces under each hexagram and each line, so that classic and commentary are read straight through together, and the two become harder still to tell apart. This arrangement is generally thought to have begun with commentators between the Han and the Wei, and to have become standard along with Wang Bi's annotated edition.
Two ways the name "I Ching" is used
- The narrow sense: the classic alone, as opposed to the Yizhuan (易传, the "Commentaries on the Changes"). When scholars say "the Yijing dates from the Western Zhou and the Yizhuan from the Warring States", this is the sense they mean.
- The broad sense: the whole book, classic and commentaries bound together. The Han dynasty established the Changes as one of the Five Classics and honored the Ten Wings as part of the classic along with it. From then on "I Ching" became the common name for the whole book, referring to the same thing as "Zhouyi". An I Ching and a Zhouyi in a bookstore usually have the same contents.
There is one more account: that there was more than one Changes. The Zhouli ("Rites of Zhou") records that the Grand Diviner was in charge of three Changes, named Lianshan, Guicang and Zhouyi; the later claim that the Lianshan belonged to the Xia dynasty and the Guicang to the Shang is only tradition. The Lianshan and the Guicang were lost long ago. Only their names survive, along with scattered fragments collected by later scholars. Among the Qin bamboo slips excavated at Wangjiatai in Hubei in the 1990s, one group matches the fragments of the Guicang that had been handed down, and most scholars believe the slips are connected with it, but the work as a whole can no longer be known. Only the Zhouyi has come down complete, so when people say "I Ching" today, the Zhouyi is in practice what they mean.
Which parts this site uses
- Judgments and line statements: the classic. These are what you read after casting; which one to read follows Zhu Xi's seven rules.
- The Tuan commentary: given on each hexagram's own page, as an aid to understanding the judgment.
- The Image commentary: the Image appears under each hexagram, the small Image commentary under each line.
The Xici and the Shuogua do not appear hexagram by hexagram, but the guides often draw on them: the method of casting with yarrow stalks comes from the Xici (see The yarrow-stalk method and the coin method), and the images of the eight trigrams come from the Shuogua (see The eight trigrams chart). The other three, the Wenyan, the Xugua and the Zagua, are not included on this site at present. For which editions the text of the classic follows and how it was collated, see Sources and method; the original text of each hexagram can be found from The 64 hexagrams.