I Ching

The I Ching (Yijing, or *Book of Changes*) is one of the oldest Chinese classics, originally used as a divination manual during the Western Zhou period (1000–750 BC). By the Warring States and early imperial eras (500–200 BC), it had evolved into a cosmological work, accompanied by philosophical commentaries called the Ten Wings. In the 2nd century BC, it became one of the Chinese Five Classics, and for centuries afterward it served as the foundation for divination practices across the Far East, attracting extensive scholarly analysis. From the 18th to the 20th centuries, it also shaped Western interpretations of East Asian philosophy.

The divination method, known as I Ching divination, involves manipulating bundles of yarrow stalks to produce six numbers between 6 and 9. Each set of numbers corresponds to one of 64 hexagrams, which are arranged in the King Wen sequence and can be looked up in the text. The meanings of these readings have been debated for centuries, with many commentators using the book symbolically to guide moral decisions, drawing on Confucian, Taoist, and Buddhist ideas. The hexagrams themselves have also taken on cosmological significance, often linked to concepts like yin and yang and the Five Phases (Wuxing).

The core of the I Ching is a Western Zhou divination text called the *Changes of Zhou* (Zhou yi). Modern scholars date its assembly in roughly its current form to between the 10th and 4th centuries BC. Based on comparisons with bronze inscriptions, sinologist Edward Shaughnessy places its compilation in the late 9th century BC, during the early reign of King Xuan of Zhou (r. c. 827–782 BC). A copy found in the Shanghai Museum corpus of bamboo slips shows that by 300 BC, the *Zhou yi* was used across all levels of Chinese society, though minor variations persisted into the Warring States period (c. 475–221 BC). Other divination systems, such as the *Lianshan* and *Guicang*, may have existed at the same time, as noted in the *Rites of Zhou*.

The name *Zhou yi* literally means the "changes" of the Zhou dynasty. These changes have been interpreted as transformations of hexagrams, their lines, or the numbers from divination. Feng Youlan suggested the word for "changes" originally meant "easy," implying a simpler form of divination than oracle bones, but evidence for this is scant. An ancient folk etymology sees the character as containing the sun and moon, representing the daily cycle. Modern sinologists believe the character derives either from an image of the sun emerging from clouds or from the act of changing the contents of a vessel.

Traditionally, the *Zhou yi* was attributed to King Wen of Zhou, the Duke of Zhou, and the legendary ruler Fuxi, with another tradition linking it to Tang of Shang. The canonical *Great Commentary* states that Fuxi created the eight trigrams by observing the world's patterns, but the *Zhou yi* itself does not mention this legend or its own origins. The *Rites of Zhou* also claims the hexagrams came from an initial set of eight trigrams. During the Han dynasty, opinions varied on the historical relationship between trigrams and hexagrams, but by the 2nd century AD, a consensus—attributed to scholar Ma Rong—held that the text was a joint work of Fuxi, King Wen, the Duke of Zhou, and Confucius. This traditional attribution is no longer widely accepted.

The basic unit of the *Zhou yi* is the hexagram, composed of six stacked horizontal lines, each either broken or unbroken. The received text contains all 64 hexagrams, each with a name, a short hexagram statement, and six line statements. These statements were used to interpret divination results, but why two methods of reading exist—and which takes precedence—remains unknown. The book opens with the phrase *yuán hēng lì zhēn*, repeated often in hexagram statements and considered important for interpretation as early as the 6th century BC. Edward Shaughnessy translates this as affirming an "initial receipt" of an offering, "beneficial" for further "divining." The word *zhēn* was used for the verb "to divine" in Shang dynasty oracle bones and also meant being upright or correct; Eastern Han scholar Zheng Xuan defined it as "to enquire into the correctness" of a proposed action. Hexagram names usually appear in their line statements, but in five cases (hexagrams 2, 9, 26, 61, and 63), an unrelated character of unclear purpose is used.