Proof of Heaven is the name of the new book by Dr. Eben Alexander III, and that's what it convincingly delivers. Before his own near death experience during a 7-day coma, Dr. Alexander, a neurosurgeon who taught at Harvard Medical School, was a confirmed skeptic and dismissed reports of mystical experiences connected with NDEs as imagination or chemical imbalance. He regarded the brain as the seat of consciousness, but neither he nor his medical colleagues could explain the vivid memories he recalled from within his coma when he was essentially brain dead.