The American Heritage Dictionary, published in 1973, defines a ghost as, "the spirit or shade of a dead person, supposed to haunt living persons or former habitats." Unfortunately, this simple definition does not explain where a ghost comes from or why it haunts. When used in the context of Shakespeare's Hamlet, this definition seems to suggest that the ghost who visits Hamlet truly is his dead father seeking revenge. To the modern reader, this straightforward interpretation adequately characterizes the ghost and his purpose; however, to the ....