"Change, Yi, or I, is the most mysterious word of all. It is a quality of the world we live in, an inner, creative energy as well as the name of a divination book & technique associated with it. It is also applied to the school that uses this mysterious quality as a spiritual way.The book and processes called I or Yi actually contain many kinds of change. There are images of the orderly changes in nature, like the seasons or the stages of life. There are images of transformation like water turning to ice, a caterpillar turning into a butterfly or a live person turning into a dead person. There are images of cyclic alternation like day turning into night or yin turning into yang. There are images of depletion, of exhaustion, and of rebirth.
Though it includes these things, change itself is something different. Its primary meaning is 'trouble.' It was first used to indicate sudden, disastrous storms, unexpected losses or times of political upheaval when confusion intervenes. Structures break down; something extraordinary happens. The world, in one way or another, reverts to chaos. It is a time of troubles.
Another meaning of change shows the response to trouble: versatility, imaginative mobility, openness and ease. It suggests a fluid personal identity, a fertile imagination and the capacity to move with the breakdown of normal values. It is as mysterious, unpredictable and fertile as the Tao.
Through change you can move as fluidly and unpredictably as the chaotic force it represents. The spirits and symbols of the Book of Changes connect the change of the universe to your own inner change, your creative imagination, if you choose to use them."
-- Stephen Karcher, Ph. D., Ta Chuan, The Great Treatise