Hamlet may already be going mad when the play begins, and his later decision to fake madness is just a cover for real insanity. The first line addressed to Hamlet is: “How is it that the clouds still hang on you?” (I.ii.): Claudius thinks it’s strange and unhealthy that Hamlet is still grieving for his father. In the same scene Hamlet tells us that he is wearing “solemn black” and a “dejected ‘havior” (I.ii.), which audiences in Shakespeare’s time would have recognised as signs of “melancholy,” a condition which Renaissance doctors believed could lead to madness. Although several characters see the Ghost during Act One, only Hamlet hears it speak, which opens the possibility that the Ghost’s speech is a hallucination of Hamlet’s. Later Hamlet wonders the same thing, asking whether the Ghost’s story was a trick played on him by the Devil, “Out of my weakness and my melancholy,/As he is very potent with such spirits” (II.ii.). The possibility that Hamlet is mad when the play begins forces us to question the truth of everything he says, making his character even more mysterious.
Hamlet’s misogynistic behavior toward Gertrude and Ophelia can be seen as evidence that Hamlet really is going mad, because these scenes have little to do with is quest for justice, and yet they seem to provoke his strongest feelings. We see little evidence in the play that either Gertrude or Ophelia is guilty of any wrongdoing, and they both appear to feel genuine affection and concern for Hamlet. Yet he treats them both with paranoia, suspicion, and cruelty, suggesting he has lost the ability to accurately interpret other people’s motivations. Hamlet describes Gertrude’s marriage as “incestuous” (I.ii.), but no one else in the play agrees with his opinion. Even though the Ghost instructs Hamlet not to “contrive against thy mother aught” (I.v), Hamlet’s disgust with his mother’s sex life mounts as the play continues: when he finally confronts Gertrude he paints a picture of her “honeying and making love over the nasty sty” (III.iii). Hamlet demonstrates a similar attitude to Ophelia’s sexuality, telling her “Get thee to a nunnery” rather than become “a breeder of sinners” (III.i). After giving Ophelia a long list of what he sees as women’s faults, Hamlet confesses: “It hath made me mad” (III.i). The fact that Hamlet’s biggest emotional outbursts are directed against the sexual feelings of the women in his life suggests that his mad behavior is not just a ploy to disguise his revenge plans.
Despite the evidence that Hamlet is actually mad, we also see substantial evidence that he is just pretending. The most obvious evidence is that Hamlet himself says he is going to pretend to be mad, suggesting he is at least sane enough to be able to tell the difference between disordered and rational behavior. Hamlet tells Horatio and Marcellus that he plans to “put an antic disposition on” (I.v). His “mad” remarks to Polonius—“you are a fishmonger” (II.ii)—are too silly and sometimes too clever to be genuinely mad: even Polonius notes “How pregnant sometimes his replies are” (II.ii.). Hamlet’s most mad-seeming outburst, against Ophelia, may be explained by the fact that Claudius and Polonius are spying on the conversation: if Hamlet suspects that he’s being spied on, he may be acting more deranged than he really is for the benefit of his listeners. If Hamlet does know that Claudius and Polonius are listening, the fact that he can instantly adjust his behavior points toward the idea that he has a firm grip on reality and his own mind. Similarly, when Hamlet is sent to England, he acts skilfully and ruthlessly to escape, which suggests that even at this late stage in the play he is capable of perfectly sane behavior. For every piece of evidence that Hamlet is mad, we can also point to evidence that he’s sane, which contributes to the mystery of Hamlet’s character.
By making the audience constantly question whether Hamlet is really mad or just pretending, Hamlet asks us whether the line between reality and acting is as clear-cut as it seems. Hamlet tells us that he believes the purpose of acting is “to hold, as ’twere, the mirror up to Nature” (III.ii), that is, to be as close to reality as possible. The First Player cries as he delivers a sad speech, and Hamlet asks whether the Player’s pretended feelings are stronger than his own real feelings, since Hamlet’s feelings are not strong enough to make him cry. Hamlet seems to believe that acting can be as real, or realer, than real-life emotion, which raises the possibility that by pretending to be mad, Hamlet has actually caused his own mental breakdown. Another interpretation could be that Hamlet acts mad as a way to express the strong, troubling emotions he can’t allow himself to feel when he’s sane, just as the actor can cry easily when playing a role. Throughout the play, Hamlet struggles to determine which role he should play—thoughtful, reticent scholar, or revenge-minded, decisive heir to the throne—and by acting both parts, Hamlet explores what his true role should be. Hamlet forces us to question what the truth is: how can we tell between reality and pretense?