Some books were not written. They were arrived at: by many hands, over many centuries, in the slow accumulation of a way of seeing.

The book you are about to consult is the oldest of these. It is older than the Iliad, older than the Hebrew Bible, and older by a long measure than the schools of philosophy that eventually named it.

Its earliest layers were laid down in northern China, more than three thousand years ago, by figures whose names did not survive. They never held the book as their own; they served it as scribes. Watching the patterns of weather and field, of harvest and counsel, of marriage and war, they came to see that nothing in that turning was random, and that change itself had a grammar.

What they were assembling they called the Yi Jing: the Book of Changes.

What they had made was less a system of prediction than a map of how change moves.