The I Ching (or Yi Jing) is a three thousand years old Chinese divinatory system. Its 64 hexagrams (figures consisting of six whole or broken lines) are thought to represent all the basic combinations of yin and yang in the universe and therefore to encompass “all under heaven”. Divination is performed by casting forty-nine yarrow stalks or tossing three coins to select a hexagram, and then reading the texts associated with that hexagram. Beside its oracular use, the I Ching has been in China for over two thousand years a book of wisdom and a fundamental map of reality in which all other systems of knowledge, from medicine to martial arts, were grounded.
Rudolf Ritsema and Shantena Augusto Sabbadini
The Original I Ching Oracle: The Pure and Complete Texts with Concordance
Watkins Publishing, London, 2005