Hamlet fits in a literary tradition called the revenge play, in which a man must take revenge against those who have in some way wronged him. Yet Hamlet turns the revenge play on its head in an ingenious way: Hamlet, the man seeking revenge, can't actually bring himself to take revenge. For reason after reason, some clear to the audience, some not, he delays. Hamlet's delay has been a subject of debate from the day the play was first performed, and he is often held up as an example of the classic "indecisive" person, who thinks to much and acts too little. But Hamlet is more complicated and interesting than such simplistic analysis would indicate. Because while it's true that Hamlet fails to act while many other people do act, it's not as if the actions of the other characters in the play work out. Claudius's plots backfire, Gertrude marries her husband's murderer and dies for it, Laertes is manipulated and killed by his own treachery, and on, and on, and on. In the end, Hamlet does not provide a conclusion about the merits of action versus inaction. Instead, the play makes the deeply cynical suggestion that there is only one result of both action and inaction—death.
In Act 1, scene 2 of Hamlet, Gertrude asks why Hamlet is still in mourning two months after his father died: "Why seems it so particular with thee?" Hamlet responds: "Seems, madam? Nay, it is, I know not 'seems.'" (1.2.75-76). The difference between "seems" (appearance) and "is" (reality) is crucial in Hamlet. Every character is constantly trying to figure out what the other characters think, as opposed to what those characters are pretending to think. The characters try to figure each other out by using deception of their own, such as spying and plotting.
But Hamlet takes it a step further. He not only investigates other people, he also peers into his own soul and asks philosophical and religious questions about life and death. Hamlet's obsession with what's real has three main effects: 1) he becomes so caught up in the search for reality that he ceases to be able to act; 2) in order to prove what's real and what isn't Hamlet himself must hide his "reality" behind an "appearance" of madness; 3) the more closely Hamlet looks, the less real and coherent everything seems to be. Many analyses of Hamlet focus only on the first effect, Hamlet's indecisiveness. But the second two effects are just as important. The second shows that the relationship between appearance and reality is indistinct. The third suggests that the world is founded on fundamental inconsistencies that most people overlook, and that it is this failure to recognize inconsistencies that allows them to act. Hamlet's fatal flaw isn't that he's wrong to see uncertainty in everything, but that he's right.
There are two important issues regarding women in Hamlet: how Hamlet sees women and women's social position. Hamlet's view of women is decidedly dark. In fact, the few times that Hamlet's pretend madness seems to veer into actual madness occur when he gets furious at women. Gertrude's marriage to Claudius has convinced Hamlet that women are untrustworthy, that their beauty is a cover for deceit and sexual desire. For Hamlet, women are living embodiments of appearance's corrupt effort to eclipse reality.
As for women's social position, its defining characteristic is powerlessness. Gertrude's quick marriage to Claudius, though immoral, is also her only way to maintain her status. Ophelia has even fewer options. While Hamlet waits to seek revenge for his father's death, Ophelia, as a woman, can't act—all she can do is wait for Laertes to return and take his revenge. Ophelia's predicament is symbolic of women's position in general in Hamlet: they are completely dependent on men.
Every society is defined by its codes of conduct—its rules about how to act and behave. There are many scenes in Hamlet when one person tells another how to act: Claudius lectures Hamlet on the proper show of grief; Polonius advises Laertes on practical rules for getting by at university in France; Hamlet constantly lectures himself on what he should be doing. In Hamlet, the codes of conduct are largely defined by religion and an aristocratic code that demands honor and revenge if honor has been soiled.
But as Hamlet actually begins to pursue revenge against Claudius, he discovers that the codes of conduct themselves don't fit together. Religion actually opposes revenge, which would mean that taking revenge could endanger Hamlet's own soul. In other words, Hamlet discovers that the codes of conduct on which society is founded are contradictory. In such a world, Hamlet suggests, the reasons for revenge become muddy, and the idea of justice confused.
In medieval times people believed that the health of a nation was connected to the legitimacy of its king. In Hamlet, Denmark is often described as poisoned, diseased, or corrupt under Claudius's leadership. As visible in the nervous soldiers on the ramparts in the first scene and the commoners outside the castle who Claudius fears might rise up in rebellion, even those who don't know that Claudius murdered Old Hamlet sense the corruption of Denmark and are disturbed. It is as if the poison Claudius poured into Old Hamlet's ear has spread through Denmark itself.
Hamlet also speaks in terms of rot and corruption, describing the world as an "unweeded garden" and constantly referring to decomposing bodies. But Hamlet does not limit himself to Denmark; he talks about all of life in these disgusting images. In fact, Hamlet only seems comfortable with things that are dead: he reveres his father, claims to love Ophelia once she's dead, and handles Yorick's skull with tender care. No, what disgusts him is life: his mother's sexuality, women wearing makeup to hide their age, worms feeding on a corpse, people lying to get their way. By the end of the play, Hamlet argues that death is the one true reality, and he seems to view all of life as "appearance" doing everything it can—from seeking power, to lying, to committing murder, to engaging in passionate and illegitimate sex—to hide from that reality.