According to Eugene Taylor, a historian and philosopher of psychology, the spiritual renaissance of our time can be seen as a Third Great Awakening in American religious life. It is characterized by an interest in esoteric and mystical traditions, an emphasis upon the alteration of consciousness, and a wild eclecticism. He also sees this movement as a shadow culture of Judeo-Christian Protestantism containing a folk psychology — "a mythic and visionary language of immediate experience — a spontaneously generated language of interior life, the function of which is self-realization."

With great erudition and confidence, Dr. Taylor, who is an internationally renown expert on William James, maps the roots of today's explosion of spirituality in the ideas, utopian schemes, and practices of three centuries of American shadow culture. Among the colorful characters assessed are Conrad Beissel, leader of the Ephrata Mystics; Margaret Fuller and the new psychology of the feminine; Emanuel Swedenborg's idea of correspondences; and James Freeman Clark's ideal of spiritual self-realization.

Taylor examines the following nineteenth century developments: the rise of utopian communities; the practice of homeopathy, phrenology and mesmerism as alternative therapeutic systems; the investigation of the occult; and the Americanization of Asian ideas as well as the theories of Jung and Freud. The book also contains an overview of Esalen and the counterculture movement of the 1960s. Dr. Taylor concludes with a few prescient prophecies on where the American visionary psychology will go next.