The main theme of Macbeth—the destruction wrought when ambition goes unchecked by moral constraints—finds its most powerful expression in the play’s two main characters. Macbeth is a courageous Scottish general who is not naturally inclined to commit evil deeds, yet he deeply desires power and advancement. He kills Duncan against his better judgment and afterward stews in guilt and paranoia. Toward the end of the play, he descends into a kind of frantic, boastful madness.
