Shakespeare's Definition of a Ghost
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 Elizabethan audience the ghost's identity proved more complex. For the Elizabethans, four different types of ghosts existed, each with its own purpose and qualities. Before they could determine the meaning behind the ghost's appearance, the Elizabethans had to classify the ghost in one of the four categories. Similar to the modern definition, the Elizabethans believed in the possibility of the ghost being an actual dead person sent to perform some task or mission.
On the other hand, the ghost could be the devil disguised in the form of a deceased loved one, tempting to procure the soul of one of the living. The nonbelievers among the Elizabethans saw ghosts as omens, telling of troubled time ahead, or simply as the hallucinations of a crazed person or group. Shakespeare recognized the complexity of the Elizabethan ghost's identity and played off of the confusion, making the question of identity a key theme to his play. Throughout Hamlet Shakespeare explores each of the possible identities of the ghost with each one adding a new twist to Hamlet's plight.
When news of the ghost's presence first reaches Hamlet and Horatio, they declare it an omen of forthcoming evil. Hamlet's reaction indicates that he is not surprised, 'My father's spirit - in arms?...