Understand in about 6 minutes
An ancient Chinese manual of divination built from sixty-four six-line figures, read by Confucian tradition as a map of how strong and yielding forces move through every situation and turn ceaselessly into one another.
Mind Map
Core Message
The whole book rests on two marks: a whole line and a divided line, the strong and the weak, later named yang and yin. Stacked three at a time they form eight trigrams, and doubled into six they form the sixty-four hexagrams. Each figure is a small picture of a situation, and its meaning is read off the kind and position of its lines.
The book's own title points to change. The Great Appendix defines change as production and reproduction without end, and treats the alternation of the inactive and active operations as the very course of things. No situation is fixed; a strong line gives way to a weak one, and circumstances pass into their opposites.
Under each hexagram King Wan gives a short judgment on the whole figure, the duke of Kau adds a reading of each separate line, and a later treatise draws a moral image from it. The diviner does not just learn an outcome; he is told whether to advance or withdraw, and how the superior man should act in that position.
Legge stresses that the appendixes turn the figures into ethics. Heaven in its motion suggests strength, so the superior man nerves himself to ceaseless activity; the earth's receptivity suggests breadth of virtue. Reading the cosmos becomes a way of correcting one's own conduct and timing.
Summary
The I Ching, or Book of Changes, is one of the oldest books in the Chinese canon. At its base lie sixty-four figures, each made of six horizontal lines that are either whole or divided. James Legge, whose 1882 translation this page follows, separates the work into two layers that grew centuries apart: the Text, a brief judgment on each figure with notes on its individual lines, and the Appendixes, a set of later commentaries that the Confucian tradition received as part of the classic.
The lines are the alphabet of the system. A whole line stands for the bright, strong, active force and a divided line for the dark, weak, yielding force, the pair the appendixes name yang and yin. Tradition holds that the legendary Fu-hsi first devised the eight trigrams of three lines each, that King Wan multiplied them into the sixty-four hexagrams while imprisoned, and that his son the duke of Kau wrote the explanations of the separate lines. What a line means depends on whether it is strong or weak, where it sits, and how it answers the line that corresponds to it.
Each hexagram is meant to capture a typical situation. The first, Khien, is six whole lines and represents what is great and originating, pictured through a dragon that hides, appears, rises, and at last overreaches. The second, Khwan, is six divided lines and represents the receptive earth. From the opening pair onward, the readings move between fortune and misfortune, repentance and regret, advance and retreat, always tying the abstract figure to a concrete question a person might bring to the oracle.
The deeper philosophy lives in the appendixes, above all the Great Appendix. There the figures are matched to the workings of nature: heaven is high and earth is low, movement and rest mark the strong and the weak, and the strong and weak lines displace each other to produce all the changes. Change itself is defined as production and reproduction without end, and the alternating play of the inactive and active operations is called the course of things. The good see this course and call it good; the wise call it wisdom; ordinary people live by it daily without knowing it.
Legge presents the book soberly. He treats it first as a manual of divination, preserved when other ancient texts were burned because it was useful for telling fortunes, and only later overlaid with the moral and cosmological readings of the Confucian school. He resists the idea that the figures hide a secret science, yet he takes seriously how the tradition used them: as a mirror held up to nature in which the superior man learns the right timing for action and restraint, and reads in the ceaseless turning of strong and weak the pattern of his own conduct.
Key Concepts
Every figure is built from two marks, a whole line and a divided line, standing for the strong and the weak, the bright and the dark, later called yang and yin. Their kind, place, and pairing decide a reading.
These two lines are the basic vocabulary of the entire book. Grasping them is what lets a reader see a hexagram as a structured situation rather than an arbitrary symbol.
Eight trigrams of three lines, drawn from natural images such as heaven, earth, thunder, and water, are doubled into sixty-four six-line hexagrams, each named for a typical condition or affair.
The hexagrams give the book its scope. They aim to classify the kinds of situation a person can be in, so that a chosen figure can speak to a real question.
The appendixes define change as production and reproduction without end and treat the alternation of active and inactive forces as the course of things, so that strong gives way to weak and conditions turn into their opposites.
This is the idea the title names. It frames every reading: because nothing holds still, the question is always one of timing and direction, not of a fixed verdict.
Mental Models
A line's worth comes not from being strong or weak in itself but from whether it sits in a fitting place and answers its correlate. A strong line in the right place commands well; the same line out of place brings danger.
It trains a reader to ask not only what they are but where they stand, weighing strengths and weaknesses against the situation and the time rather than in isolation.
Because change is production and reproduction without end, no condition is permanent. A topmost line that overreaches brings repentance, and fullness tends toward decline, so the wise act before a state runs to its extreme.
It encourages acting with the grain of change: pressing on when the moment rises and drawing back before success hardens into excess.
The image treatises draw a moral from each figure's natural picture. Heaven in motion suggests tireless strength, the earth suggests broad receptivity, and the superior man patterns his conduct on what the figure shows.
It offers a way to convert observation into action, reading steadiness, restraint, or vigour out of the situation before you and applying it to your own behaviour.
Selected Quotes
Production and reproduction is what is called (the process of) change.
The successive movement of the inactive and active operations constitutes what is called the course (of things).
Heaven, in its motion, (gives the idea of) strength. The superior man, in accordance with this, nerves himself to ceaseless activity.
Source
Source text: Internet Archive scan of The Yi King, translated by James Legge (The Sacred Books of the East, Vol. XVI, 1882).
HTML text: https://archive.org/download/in.gov.ignca.20915/20915_djvu.txt
The James Legge translation was published in 1882 and is in the public domain. This page draws on a public-domain scan held by the Internet Archive.
This English translation, titled 'The Yi King', was made by James Legge and published in 1882 as Volume XVI of The Sacred Books of the East. The underlying Chinese text is far older, with its core attributed to King Wan and the duke of Kau and its appendixes to the Confucian school.