Shakespeare gave Macbeth exactly one murder to commit and then spent five acts showing what that murder did to the man who committed it. Macbeth kills Duncan in Act Two. He spends Acts Three through Five killing everyone who might know, might suspect, or might eventually threaten him, and each additional murder makes him less safe rather than more. The play is not about ambition rewarded. It is about ambition eating itself, a man who climbed to the top of the world and discovered that the view from there is nothing but enemies in every direction.

Harold Bloom, in Shakespeare: The Invention of the Human, argued that Macbeth possesses the most powerful imagination of any Shakespeare character, and that imagination is precisely what destroys him. Macbeth sees the dagger before he kills Duncan. He hears voices after the murder that tell him he shall sleep no more. He sees Banquo's ghost at the feast. His mind produces the evidence of his guilt faster than his hands can eliminate the witnesses, and no amount of violence can quiet a conscience that speaks in hallucinations.

The Partnership That Devoured Itself

Lady Macbeth is frequently read as the instigator, the woman who pushed her husband to murder. This is partly true but mostly insufficient. She provides the plan and the nerve. He provides the sword and the imagination. Together they form a complete murderer, and apart they disintegrate. Lady Macbeth sleepwalks, washing invisible blood from her hands. Macbeth becomes increasingly isolated, making decisions without consulting her, until their partnership has dissolved into two separate people drowning in the same crime.

Dr. Stephen Greenblatt of Harvard, in his work on Shakespeare and tyranny, has argued that Macbeth dramatizes the isolation that power produces. The more Macbeth controls, the less he can trust. The less he trusts, the more he controls. It is a feedback loop with no stable equilibrium, and Shakespeare understood this dynamic four centuries before political science gave it a name.

Tomorrow and Tomorrow and Tomorrow

Macbeth's final soliloquy is the bleakest passage Shakespeare ever wrote. Life is a tale told by an idiot, full of sound and fury, signifying nothing. This is not a villain's manifesto. It is the honest assessment of a man who got everything he wanted and discovered that wanting was the only part that had any energy in it. The crown is meaningless. The power is meaningless. The murders were meaningless. And Macbeth knows all of this and goes out to fight anyway, because fighting is the last thing left.