The I Ching is one of the oldest of the Chinese classic texts. The book contains a divination system and 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 BCE. Some consider the I Ching the oldest extant book of divination, dating from 1,000 BCE and before. The standard text reproduced here is based on Fei Zhi's text which survived the book-burning of the Qin.