So glorious, so mysterious, the Holy Grail symbolizes an elusive object of desire. Although now usually identified as the chalice of the Last Supper sought by Arthurian heroes, the Grail has been pictured as a dish, a ciborium, and even a white stone. Indeed, for a long time, its name had a rather mundane meaning. The word "grail" is derived through Old French from the Latin gradale (by degrees) and refers to a type of deep platter from which foods were served -- course by course -- at a medieval banquet. "Grail" is first recorded in English in...