Key to the construction of hexagrams, The I Ching, or Classic of Changes, is an ancient divination text and the oldest of the Chinese classics. The I Ching uses a type of divination called cleromancy, which produces apparently random numbers. Four numbers, 6 to 9, are turned into a hexagram, which can then be looked up in the I Ching book, arranged in an order known as the King Wen sequence. The interpretation of the readings found in the I Ching is a matter of centuries of debate, and many commentators have used the book symbolically, often to provide guidance for moral decision making as informed by Taoism and Confucianism. The hexagrams themselves have often acquired cosmological significance and paralleled with many other traditional names for the processes of change such as yin and yang and Wu Xing.