Plato and the Greeks called it "daimon," the Romans "genius," the Christians "guardian angel"; today we use terms such as "heart," "spirit," and "soul." For James Hillman it is the central and guiding force of his utterly unique and compelling "acorn theory," which proposes that each life is formed by a particular image, an image that is the essence of that life and calls it to a destiny, just as the mighty oak's destiny is written in the tiny acorn. It is a theory that offers a liberating vision of childhood troubles and an exciting approach to themes such as fate and fatalism, character and desire, family influence and freedom, and, most of all, calling - that invisible mystery at the center of every life that speaks to the fundamental question "What is it, in my heart, that I must do, be, and have? And why?"