1. Representation of Truth and Revelation: The ghost serves as a vehicle to reveal the truth about the circumstances surrounding Hamlet's father's death. The play opens with the ghost appearing to Horatio and the guards on the castle's ramparts, thereby setting in motion the chain of events that drive the plot forward.
2. Symbol of Revenge: The ghost's primary mission is to demand revenge from Hamlet for the murder committed by Claudius, Hamlet's uncle. The ghost urges Hamlet to "Revenge his foul and most unnatural murder."
3. Embodiment of Guilt and Conscience: The ghost's appearance, especially to Hamlet, also symbolizes the guilt and moral weight that hangs over Claudius and Gertrude for their crimes. The ghost serves as a haunting reminder of the consequences of their actions.
4. Symbol of Corruption: The ghost's presence represents the corruption and moral decay that have befallen the Danish court. The appearance of a supernatural entity signifies a rupture in the natural order and the disruption of societal norms.
5. Mortality and the Supernatural: The ghost's specter highlights the supernatural elements within the play, blurring the lines between the living and the dead. The ghost's existence raises questions about the nature of reality and afterlife.
6. Hamlet's Internal Struggle: The ghost can also be interpreted as a manifestation of Hamlet's internal conflicts, representing his struggle with indecision, grief, and the heavy burden of revenge.
The ghost in Hamlet serves as a multi-faceted symbol that drives the plot, embodies different themes, and adds layers of complexity to the play. Shakespeare masterfully uses the ghost to create a sense of intrigue, suspense, and philosophical depth.