Composed in 2 B.C., as "The I Ching revised and enlarged", The Elemental Changes is a divination manual providing a clear method for distinguishing alternative courses of action. Structured in 81 tetragrams (as opposed to the 64 hexagrams of the I Ching), the book offers much to the modern reader. Today in the West, The Elemental Changes is an essential tool for understanding the Tao as is operates in the Cosmos, in the minds of sages, and in sacred texts. It is also one of the great philosophical poems in world literature, assessing the rival claims on human attention of fame, physical immortality, wealth, and power while it situates human endeavor within the larger framework of cosmic energies. The complete text of The Elemental Changes and its ten autocommentaries are here translated into accessible and, whenever possible, literal English. Following the Chinese tradition, supplementary comments are appended to each tetragram in order to indicate the main lines of interpretation suggested by earlier commentators.