This book is a thematic and comparative study of the mystical traditions of Hinduism, Buddhism, Taoism, Kabbalah, Christian mysticism, and Sufism. The guiding assumptions of this study are: just as there are stages of human development, so there are corresponding stages of religion; transpersonal stages of religion correspond to transpersonal stages of human development; just as no account of human nature can be completed without considering the transperson, so no account of religion can be complete without delineating its transpersonal stages. The personal and transpersonal may be called, respectively, conventional and experiential religion. Each addresses different stages of human development.