He could be crazy, and it could be all in his mind. Or it could be an illusion created by the devil to trick him into killing his uncle. Hamlet actually considers this possibility and as a result decides to test the Ghost's information.
He decides to "put an antic disposition on" and to swear his friends to secrecy.
We are informed of elder Hamlet's death by seeing his ghost appear.
Hamlet's mother died by drinking a goblet of wine that was supposed to go to Hamlet. The King had poisoned the wine in an attempt to kill Hamlet and seeing his queen about to take a sip, he tries to persuade her otherwise. She drinks anyway.
In Act I, after seeing the ghost, Hamlet goes a little loopy. It's not all that surprising.
What you think you believe you're seeing, is actually an illusion. That's my opinion of that text anyway.
Polonius is interested in seeing whether spying on Hamlet's conversation with Gertrude will justify his theory that Hamlet is mad for love. (see the end of Act 3 Scene 1)
The phrase, 'Seeing is Believing' is an expression that simply says you don't believe it until you see it. The phrase 'Believing is Seeing' means that believing is like seeing. If you don't believe in Santa, or 'Seeing is Believing, you won't believe it until you see him. If you do believe in him, 'Believing is Seeing', then it is like seeing him because you do believe.
MacBeth ends up seeing the ghost of his friend Banquo during his dinner party he throws in (and double check this) Act 4 i believe. Also, before MacBeth kills Duncan in Act 2 he sees a floating dagger as a hallucination. The ghost though, is Banquo.
No, you've got it backwards. It is Horatio who says, "These are but wild and whirling words, my lord." to Hamlet. Hamlet is a little discombobulated after seeing his father's ghost.
Ophelia tells Hamlet that she has been sewing in her room and has not been seeing him. This lie is part of her attempt to navigate the complex dynamics of their relationship and the pressures from her father, Polonius, and brother, Laertes, who advise her to distance herself from Hamlet. Her deception reveals the conflict between her loyalty to her family and her feelings for Hamlet.
In "Hamlet", Polonious devises a plan to test his theory that Hamlet is madly in love with Ophelia, and since she is ignoring him, he is depressed. He plans to arrange for Hamlet and Ophelia to meet. He will hide close by and ease-drop to determine if he is correct in his assumption.
Horatio didn't believe in ghosts. After seeing the ghost for the first time, he said the following:Horatio: Before my God, I might not this believeWithout the sensible and true avouchOf mine own eyes.Hamlet : Act 1 Scene 1