The I Ching (Wade-Giles) or "Yì Jīng" (pinyin), also known as the Classic of Changes, Book of Changes or Zhouyi, is one of the oldest of the Chinese classic texts. The book contains a divination system comparable to Western geomancy or the West African Ifá system; in Western cultures and modern East Asia, it is still widely used for this purpose.
Traditionally, the I Ching and its hexagrams were thought to pre-date recorded history, and based on traditional Chinese accounts, its origins trace back to the 3rd to the 2nd millennium BC. Modern scholarship suggests that the earliest layers of the text may date from the end of the 2nd millennium BC, but place doubts on the mythological aspects in the traditional accounts. Some consider the I Ching the oldest extant book of divination, dating from 1,000 BC and before. The oldest manuscript that has been found, albeit incomplete, dates back to the Warring States Period (475–221 BC).
During the Warring States Period, the text was re-interpreted as a system of cosmology and philosophy that subsequently became intrinsic to Chinese culture. It centered on the ideas of the dynamic balance of opposites, the evolution of events as a process, and acceptance of the inevitability of change.
The standard text originated from the ancient text (古文經) transmitted by Fei Zhi (费直, c. 50 BC-10 AD) of the Han Dynasty. During the Han Dynasty this version competed with the bowdlerised new text (今文經) version transmitted by Tian He at the beginning of the Western Han. However, by the time of the Tang Dynasty the ancient text version, which survived Qin’s book-burning by being preserved amongst the peasantry, became the accepted norm among Chinese scholars.
Read more about I Ching: Structure