Andrew Newberg, M.D. is an associate professor of radiology and psychiatry and an adjunct assistant professor of religious studies at the University of Pennsylvania, and director of the Center for Spirituality and the Mind. He is co-author of Why God Won't Go Away, Born to Believe, and The Mystical Mind.
Ken Wilber is one of the most influential and widely read American philosophers of our time. His writing has been translated into more than 20 languages. Ken Wilber is the author of many books, including The Spectrum of Consciousness; The Eye of Spirit; Grace and Grit; Sex, Ecology, Spirituality; A Brief History of Everything; Boomeritis; and The Marriage of Sense and Soul. Ken Wilber lives in Denver, Colorado.