Like all tragic heroes before him, Macbeth's greatest lie is to himself. He becomes blinded to his own ambition. His overbearing pride (or hubris) is so great that he fails to see as he stumbles toward his destiny. Perhaps only when Lady Macbeth commits her off-stage suicide does he begin to acknowledge the truth. "She should have died hereafter," he comments, and then adds "Tomorrow and tomorrow and tomorrow / Creeps in this petty pace from day to day / To the last syllable of recorded time . . . ."
These lines apply to us, not just as readers and playgoers, but as humans. We may not have committed murder, we may not have ambitions for power, but we all know how it feels to watch time passing. At this point in the play, we see a man emotionally raw, stripped momentarily of all his power, admitting — with self-awareness and, perhaps, with bitter self-irony — his share in the common human experience. This moment is only one of the few moments in the play when Macbeth does so. Immediately afterwards, he strides into battle with all his former arrogance, to his tragic end. Without these lines, we could not, perhaps, feel the tragedy in the same way.
We may not be Macbeth, but as playgoers and readers, we encounter what he does: We, too, experience visions of the supernatural. We, too, ask "Is it a dagger?" "Is it a ghost?" "Are they real?" The answer to all these questions is equivocal; they are real, in a way, and in another way, they are false, only tricks "paltering with us in a double sense." Even Macbeth is and is not real. He's an actor playing an actor, deeply aware of his twofold existence.
