Concerning Shakespeare's Hamlet, the Ghost's purpose in the play is to avenge his own death. The Ghost is the ghost of Hamlet's father, who was killed by Claudius. The ghost tells Hamlet about the murder so Hamlet can avenge him.
If you mean rhetorically, ghosts were standard characters in Elizabethan revenge tragedies, and Shakespeare uses his to establish plot and conflict in the play. The ghost is the catalyst for both. The ghost is also used in act three to rebuke Hamlet for his delay.
Since the Ghost is seen by multiple people in Act One, no one doubts its existence there. Its existence is not so clear cut in act three, however, since Gertrude is not able to see the ghost. You might be able to make an argument that Hamlet is seeing things in act three, but you can't really make the argument in act one.
I do not see how you could really argue that the ghost was not there. After all, it is not only Hamlet who can see the ghost. In fact, he is not even the first one to see it. So it can't be just part of Hamlet's imagination.
To me, the role of the ghost is to spur Hamlet into his dilemma. Without the ghost, it is hard to know how Hamlet would find out about what Claudius had done. The ghost gives him this information (and tells him not to tell) that really sets up the central tension of the play.
In the beginning it would better be quoted from eNotes that, "the Ghost is important because his demand for revenge sets the plot into motion". It is the ghost who rises the major conflict in the play Hamlet.
Through the ghost's character, who is the spirit of Hamlet's dead father, Hamlet along with the audience becomes able to know that Claudius is the villain. It is because of the spirit thatHamlet feels a sense of responsibility to take revenge of his father’s murder by Claudius. The ghost makes Hamlet feel inertly confused, and leads his mind to a struggle between morality and duty.
Shakespeare's Hamlet does not represent the ghost of the dead king as a mere illusion or reflection of Hamlet's inner conscience. It appears to be a real spirit and a significant role-player in the play. It is the ghost who informs him in act 1, scene 5 about what has happened actually and what he should do now. This ghost is not like that of Banquo in Macbeth who is just a hallucination viewed by Macbeth. The most important proof is that, the ghost is also seen by Marcellus, Barnardo and Horatio for three times in scene 1 of the first act.
The ghost in Hamlet is considered as a major character. The Ghost is important because his demand for revenge. This mean that without the ghost pushing Hamlet to take revenge, Hamlet wouldn't do anything hurtful.
Throughout the tragedy, the Ghost is viewed as an illusion and a spirit which returned from the grave because of the undone mission. It is a spirit from sent with heavenly permission.
Hamlet was upset by the death of his father, as well as his mother’s hasty and marriage. He later found out that his uncle actually killed his father, and that his father’s ghost wants him to take revenge of his death. Hamlet decided to get his revenge on Claudius, and then inexplicably puts it off for the rest of the play.
The most important scenes in the play is the scene in which Hamlet met the ghost of his father, who told him of his gristly murder. The ghost is only returning to ensure his son knows the truth about his death leaving him free to rest in peace.
Finally , I believe that the ghost in Hamlet was trying to get revenge on his brother through his son. By his line wishing Hamlet not to taint his mind, it appears he really cares for his son, and from this show of emotions it proves he is not the devil but the father in a spiritual picture . Shakespeare acted the ghost on stage in the performances of Hamlet at the Globe. Adding the ghost in a tragic play made the play original and unique to the audience .