In Holinshed’s Chronicles, from which Shakespeare took his history, Macbeth not only has a claim to the throne, he also has a legitimate grievance against Duncan. Moreover, in Holinshed, Banquo is fully Macbeth’s accomplice, and the murder of Duncan has a good deal of political justification. All this would be very touchy for Shakespeare precisely because Banquo is King James’s ancestor, and if Duncan is a saint, then Banquo is a real problem, the ancestor one wants to forget. In fact, Banquo’s connection with the Scottish royal line materializes only two centuries after the events of the play, when one of his descendants, a steward in the royal household, married into the royal family–hence King James’s family name, Stewart or Stuart. Shakespeare’s way of handling Banquo fudges a lot of issues. Should he not, as a loyal thane, be pressing the claim of Malcolm, the designated heir, after the murder? Should he remain loyal to Macbeth as long as he does?

This is precisely the sort of question that shows how close the play is to Hamlet: in both plays, the issue of legitimacy remains crucially ambiguous. Nobody in Macbeth presses the claim of Malcolm until Malcolm reappears with an army to support him, any more than anyone in Hamlet presses the claim of Hamlet. In both plays, there is deep uncertainty about the relation between power and legitimacy–about whether legitimacy constitutes anything more than the rhetoric of power backed by the size of its army. Duncan tries to legitimize his son’s succession by creating Malcolm Prince of Cumberland on the analogy of the Prince of Wales, thus declaring him heir to the throne. But this is not the way the succession works in Scotland: Cumberland is an English county, which was briefly ceded to the Scottish crown, and Malcolm’s new title is the thin edge of the English invasion. Analogously, Malcolm confirms his victory at the end of the play by transforming his Scottish thanes into English earls, “the first that ever Scotland / In such an honor named” (V.8.63–64)–heredity requires a great deal of ceremonial apparatus to make it appear a natural mode of succession. James I himself became king of England not because he was the legitimate heir (he was one of a number of people with a distant claim to the throne), but because he was designated the successor by Queen Elizabeth; or at least several attendants at her death claimed that he was, and the people in control supported him. This is much closer to the situation in Hamlet and Macbeth than it is to any system of hereditary succession. And Macbeth is, even in the play, a fully legitimate king, as legitimate as Duncan: like Hamlet’s Denmark, this is not a hereditary monarchy. Macbeth is elected king by the thanes, and duly anointed. The fact that he turns out to be a bad king does not make him any less the king, any more than the rebellion that opens the play casts doubt on Duncan’s right to the throne.

The play is less about legitimacy and usurpation than about the divided self, and like Hamlet, it focuses to an unprecedented extent on the mind of the hero. Suppose we try to imagine a Hamlet written from Claudius’s point of view, in the way that Macbeth is written from Macbeth’s. The murder Claudius commits is the perfect crime; but the hero-villain quickly finds that his actions have unimagined implications, and that the political world is not all he has to contend with. As it stands, Hamlet is a very political play, and does not really need the ghost at all. Hamlet has his suspicions already; Claudius tries to buy him off by promising him the succession, but this is not good enough. It turns out that the problem is not really conscience or revenge, it is Hamlet’s own ambitions. He wanted to succeed his father on the throne; Claudius, Hamlet says, “Popped in between th’ election and my hopes.” The ghost is merely a deus ex machina. But in a Hamlet that did not center on Hamlet, Claudius’s guilty conscience, which is not much in evidence in the play, would have a great deal more work to do. So would the ghost–who should, after all, logically be haunting Claudius, not Hamlet. This play would be not about politics but about how the dead do not disappear; they return to embody our crimes, so that we have to keep repeating them–just as in Macbeth. In this version of Hamlet, Hamlet is hardly necessary, any more than in Macbeth, Malcolm and Macduff are necessary. The drama of Macbeth is really a matter between Macbeth and his ambition, Macbeth and the witches and his wife and his hallucinations and his own tortured soul, the drama of prophecies and riddles, and how he understands them, and what he decides to do about them, and how they, in themselves, constitute retribution.

What, then, about the riddles, those verbal incarnations of the imperfect speakers the witches? Macbeth is told that he will never be conquered till Birnam Wood comes to Dunsinane; and that no man of woman born will harm him. Are these paradoxical impossibilities realized? Not at all, really: the Birnam Wood prophecy does not come true, it just appears to Macbeth that it does–the wood is not moving, it merely looks as if it is. Or alternatively, we could say that “Birnam Wood” is a quibble: Macbeth assumes it means the forest, but it could mean merely wood from the forest, the branches the soldiers are using for camouflage–the prophecy comes true merely as a stage device. As for no man of woman born, maybe the problem is that Macbeth is not a close enough reader: he takes the operative word to be “woman”–“No man of woman born shall harm Macbeth”–but the key word turns out to be “born”–“No man of woman born shall harm Macbeth.” If this is right, we must go on to consider the implications of the assumption that a cesarean section does not constitute birth. This is really, historically, quite significant: a vaginal birth would have been handled by women–the midwife, maids, attendants–with no men present.