An estimated fifty million people in the world suffer from dementia. Diseases such as Alzheimer's erase parts of one's memory but are also often said to erase the self. People don't simply die from such diseases; they are imagined, in the clichés of our era, as vanishing in plain sight, fading away, or enduring a long goodbye. In On Vanishing, Lynn Casteel Harper, a Baptist minister and nursing home chaplain, investigates the myths and metaphors...