The I Ching is one of the oldest books known, dating back at least 3000 years. The I Ching is an oracle and method of divination based on a binary system reflecting the universal energies. According to Daoism (Taoism) everything originates from the Dao, or the one. It is then split into two energies (yin and yang, masculine and feminine). Everything is created from the interplay between these energies.
The I Ching produces one of 64 different yin and yang combinations when consulted. By consulting the I Ching one can gain insight into the matter at hand, whether it is an important personal decision, or the state of affairs.