The earliest composition of I Ching interpretations is attributed to King Wen. Toward the end of the Shang Dynasty, when the unjust emperor Zhou Wang imprisoned Wen, he reportedly used his confinement to meditate on the trigrams, pairing them up to produce 64 possible hexagrams. Each pair of trigrams took on a meaning specific to their combination. In what we might assume was an enlightened state of mind, King Wen assigned each of the 64 hexagrams a name, adding a few sentences to explain its meaning. It is said that his son, King Wu, added additional interpretative text, bringing the I Ching closer to its current form.
Confucius, who came a few hundred years later, was possibly the I Ching's greatest patron, taking the interpretative texts to the next level with the addition of his extensive commentaries. Confucius was primarily interested in the I Ching as a manual for how to live a life of the highest virtue, as opposed to its usefulness as a divination system. According to his Analects (VII, xvi), Confucius, who lived to be an old man, is reputed to have said, "If some years were added to my life, I would devote fifty of them to the study of the oracle, and might then avoid committing great errors."
Historical evidence substantiates the theory that the Book of Changes and its 64 hexagrams were part of an ancient oral tradition that predates recorded history in China. The basics of the I Ching text -- the names of the hexagrams and their judgments -- were likely composed in the eighth century B.C. However, the practice of using the hexagrams to refer to specific interpretations probably didn't occur until the fifth century B.C. Between 475 and 221 B.C. (known as the Warring States period), the I Ching texts were consolidated into a book to make it easier to consult and share with others during that time of extreme upheaval. Shortly after, the I Ching was spared in the Ch'in Dynasty's massive book burning because it was considered one of the five "Great Classics."
The Book of Changes was canonized and studied intently by scholars during the Han Dynasty of 202 B.C. - A.D. 220. Between the third century B.C. and the turn of the millennium, significant additions, known as the "Wings," were written regarding the individual lines in the hexagrams, and the meaning of the trigrams. These commentaries are generally attributed to Confucius, who lived around 500 B.C. More work was done, and the I Ching we use today is not substantially different from the 168 B.C. version. The main difference is that the hexagrams appear in a different order. The order in use today was first proposed around 100 B.C., but was not the standard until the third century A.D.
Throughout what we know of Chinese history, the rulers of China, as well as the general public, used the I Ching as best they could before printing was available. It is woven into the fabric of this ancient culture and its influence has been fundamental to the eastern worldview as a whole. It has only been in the last 150 years or so that western culture was even exposed to basic Taoist concepts -- such as German and English translations of the I Ching and Tao Te Ching. Carl Jung's explanation of the I Ching's psychological validity and value, and the widespread open-mindedness about all things spiritual during the 1960s, made using the I Ching a common experience in the western world.
Nowadays, the most common method for casting the I Ching involves tossing three coins six times to create the six-line pattern, or hexagram. A traditional technique for deriving a hexagram, dating from about 500 B.C., involves a fairly complicated process of selecting and sorting 50 sticks, usually yarrow stalks. The best yarrow stalks for this were the ones that grew on Confucius' grave, but the supply was limited! After the coins or stalks are tossed and sorted out, one looks up the interpretation in the sacred book.
This article was excerpted from Divination: Sacred Tools for Reading the Mind of God by Paul O'Brien