What is the I Ching, and how is it consulted?

What the I Ching is

The I Ching, also called the Book of Changes, is a text of 64 hexagrams, each made of six lines that are either broken or solid, and each hexagram carries an accompanying text.⁷⁸

Dividing a hexagram in half yields trigrams, and the eight trigrams are formed from combinations of three yang and yin lines; the trigrams are associated with sky, earth, thunder, wind, water, fire, mountain and lake.⁹¹⁰

In a hexagram, the lower trigram is called 'the inner' and the upper trigram is called 'the outer'. Lines are numbered one to six from the lowest, and whole lines are called nine while divided lines are called six.⁹

The text of the Zhou Yi is traditionally attributed to King Wen and the Duke of Zhou, and the commentaries known as the Ten Wings are traditionally credited to Confucius, although modern scholarship holds they were composed over a long period by several hands.⁴⁵

How a hexagram is consulted

The yarrow stalk method uses fifty stalks, with one set aside; the remaining 49 are divided to generate the numeric values for each line, and in Wilhelm's summary the stalks are divided and counted through by fours.¹¹¹²

In the three-coin method, heads counts as 3 and tails as 2; each cast of three coins yields a total of 6, 7, 8 or 9 that fixes a line. Three coins tossed together give a solid or broken line, and six tosses produce a hexagram.¹¹¹

In the yarrow stalk procedure, three successive changes totaling 9 make an old yang line, and totaling 6 make an old yin line; the hexagram develops from the bottom upward.¹²¹³

After the coins or stalks are tossed and sorted, the practitioner looks up the interpretation in the book. The hexagram's first and six line texts are read in order, and then the overall interpretation of the hexagram is read.¹⁰¹⁴

In six lines prediction, a Chinese practice described by a Yijing researcher, the clients are told not to voice their question until after the procedure is completed.¹⁵

Development and later readings

Early Zhou rulers consulted divination by scapulimancy, reading cracks in heated bones, or by casting lots using yarrow stalks. Shang diviners heated tortoise shells or ox scapulae, and many oracle bones have hexagrams or hexagram numbers incised on them.¹³¹

Carl Jung introduced the I Ching to many Western readers through his foreword and his interest in synchronicity, and the Wilhelm translation spread the book widely.¹¹⁰