Of the several themes present in Shakespeare's Hamlet, perhaps the most vigorously emphasized and controversially examined is that of madness. Repeatedly, the question arises as to whether or not Hamlet is insane or if he is only feigning madness.
Hamlet himself answers this question in Act One; to Horatio and the other guards in scene five, he warns:
As I perchance hereafter shall think meet
To put an antic disposition on... (191-192)
Hamlet explains that he will act in a crazy way; he also requests that no one look at him with silent understanding or a wink—everyone else must believe he is insane.
Again the question of insanity is raised as Hamlet begins his "performance" that will trick Claudius and others to discount Hamlet as a threat, and reveal the King's guilt. Acting in a strange manner, Hamlet's sanity is in question, and Polonius promises the King:
I have found
The very cause of Hamlet's lunacy. (II.ii.51-52)
When Polonius speaks to Hamlet, the Prince purposely mistakes the King's adviser as a common seller of fish. Polonius asks if Hamlet knows him, and Hamlet responds:
Excellent well. You are a fishmonger. (187)
Hamlet is also rude to Ophelia. Once sweethearts, Hamlet is cruel to the young woman he feels has betrayed him because she is trying to help the King and Queen figure out what is causing Hamlet's lunacy. In Act Three, scene one, Hamlet tells Ophelia that he never loved her. He tells her to never marry, and rants to the point that she exclaims to Heaven:
O, what a noble mind is here o'erthrown! (159)
In scene two, Hamlet assaults Ophelia's gentle sensibilities by being crude and vulgar, making sexual innuendos at the play he has arranged the Players to perform:
Lady, shall I lie in your lap?... (106)
Do you think I meant country matters? (110)
Hamlet asks Ophelia if she thought he was referring to sexual ("country") matters; more than to trick her, it seems Hamlet is trying to punish the young woman. However, the result is the same: Hamlet, indeed, seems insane.
After Hamlet mistakenly murders Polonius, and reveals the truth of Old Hamlet's death, Gertrude pretends that her son is insane in order to continue Claudius' belief that Hamlet is mad:
Mad as the sea and wind...In his lawless fit,
Behind the arras hearing something stir,
Whips out his rapier, cries 'A rat, a rat!'
And in this brainish apprehension kills
The unseen good old man. (IV.i.7-12)
An important form of madness is Ophelia's own insanity—having lost Hamlet, and then her father, at Hamlet's hands:
She speaks much of her father; says she hears
There's tricks i' the world, and hems, and beats her
Spurns enviously at straws; speaks things in doubt,
That carry but half sense. Her speech is nothing... (IV.v.5-8)
Soon after, Ophelia drowns—for centuries it has been argued as to whether she committed suicide or was driven to her death by madness. As she delivers weeds and sticks like herbs and flowers, it seems to prove her break with reality.
Hamlet, in his quest for justice, also demonstrates his deep sadness (melancholy) over his father's murder, as seen in two famous soliloquies he delivers. Both question the option of suicide. One is the "o, that this too, too sullied flesh" speech in Act One (I.ii.132-162). The other is the brilliant "To be or not to be" speech (III.i.55-87). Sadness is also present his discussion with Rosencrantz as he laments "what a piece of work is man" (II.ii.302-312).