I Ching is a traditional Chinese divination method. It involves tossing three identical coins and using the patterns they form, to receive answers to personal questions from the 'I Ching', or the Book of Changes. It is a manual of divination based upon a belief in the synchronicity of the universe. It works on the basic belief that all events occurring at a particular time are interrelated by both vertical and horizontal causality. In ancient times, oracles were in use, everywhere. The oldest among them confined themselves to the answers "yes" and "no". This type of oracular pronouncement is likewise the basis of the Book of Changes.