Hamlet's pretended madness is due to several things that occur all at once to the tragic character. First, when he returns to Denmark because of the death of his father, he is confronted with the hasty marriage of his mother to his uncle. Consequently, he is shocked by both grief and disgust. These life changing events push Hamlet into both a cycle of grief over his father's death and a deep sense of anger at his mother for her disrespect of her husband, Hamlet's father, dead for just one month before she marries her husband's brother. The level of his anger rises as he internally contemplates how this makes him feel.
If you are assessing Hamlet's "madness," it is likely that he has every reason to feel like the world itself has gone mad. The reality or truth that he knew is gone, altered, changed permanently and he cannot accept it while everyone else seems fine with it.
The fact that the Ghost of his father beings haunting him, pleading with him to avenge his death, informing him that he was in fact murdered by a man Hamlet detests, his uncle, only adds to Hamlet's sense of urgency; his reaction to this heightens his anger, his emotions. He appears consumed with a smoldering hatred; he can't get past it. To others, he appears insane, but the reader knows what is bothering him.
Shakespeare gives Hamlet a chance to internally process everything that happens to him; he is not hasty in his actions to either take revenge against his uncle or announce that he knows that the King was murdered by his uncle. Instead, Hamlet chooses to be discreet, trying to trick the new King into reacting to a play that will prove or disprove the Ghost's assertion that he was murdered.
Considering what Hamlet is dealing with, his circumstances suggest that he is in a state of emotional upheaval, not actually insane or mad, but feeling like he is going crazy because he is troubled by so many life changing events all at once.
Hamlet is an old story, and all older versions have Hamlet pretending to be mad to protect himself from Claudius by appearing harmless. Shakespeare’s play begins the same way.
- After seeing the ghost, Hamlet warns his friend, Horatio, not to worry if Hamlet starts to behave oddly. In the closet scene, Hamlet tells his mother not to let Claudius know that he is only pretending to be mad.
- Hamlet fools around with Rosencrantz and Guildenstern after realizing that Claudius had sent them to spy on him. He talks wildly with Polonius, making a fool of the old man, who is also spying for Claudius. Then after accidentally killing Polonius, Hamlet jokes about it to Claudius and acts the lunatic.
What Shakespeare does differently is leave us unsure whether this feigned madness does not hide a deeper disturbance, either insanity or immaturity.
- After wasting several opportunities to kill Claudius, Hamlet recklessly stabs through the screen in his mother’s bedroom and accidentally kills Polonius.
- After discovering that Rosencrantz and Guildenstern are carrying a sealed letter from Claudius to the King of England asking him to kill Hamlet, Hamlet changes it to an order to kill his old friends, who were only carrying out Claudius’ orders.
Before the aborted voyage to England, it is unclear whether Hamlet’s crazy behavior is all feigned or whether some is real. After the voyage, Hamlet is both sane and mature. He is a different man and there appears nothing at all of the old insanity--feigned or real--in his final acts. Although, some critics analyze the proclamation of a divinity who guides our ends (V.ii), spoken in the midst to ordered assassination and more murder to come, as an indication that Hamlet may have finally been driven mad.