When audiences first encounter Lady Macbeth, she seems a very forceful and dominant personality, and we can assume that she is the villain, or antagonist, of the play. Unlike Macbeth, who deliberates over whether or not to kill Duncan and who wrestles with loyalty to his king, Lady Macbeth is single-minded in her lust for power. She has no loyalty to any cause beyond her own ambition, and is willing to manipulate her husband to achieve what she wants. Her desire for Macbeth to be king doesn’t stem from a belief he’d be a good ruler; she wants him to be king because she wants to be queen. As a woman, queen is the most powerful role she can hope for in the court. Unlike Macbeth, who hopes there’s a way he can become king without taking action himself, Lady Macbeth immediately accepts that murder is necessary to achieve her goals, and prays for the resolve necessary to commit the act: “Come, you spirits that tend on mortal thoughts, unsex me here/ and fill me from the crown to the toe top-full/of direst cruelty.”
However, if we look more closely at the difference between who Lady Macbeth is and who she wants to be, we begin seeing a different side of Lady Macbeth, suggesting that she is not as villainous as we might have thought. While her boast to Macbeth that, if she had promised to kill her own child, she would have “dashed its brains out” without hesitation is certainly blood-chilling, she is only saying what she would do, not telling us about something she has actually done. In the lines before this shocking claim, she admits, “I have given suck, and know/How tender ’tis to love the babe that milks me.” In reality, she is capable of tenderness and warmth. Her wish to be “unsexed” and request that the spirits to “take my milk for gall,” so that she can act without remorse, indicate that, rather than lacking compassion, she fears she has too much. In fact, it may be Lady Macbeth, not her husband, who may be “too full o’ th’ milk of human kindness.”
Another contrast between what Lady Macbeth says she would do and what she actually does comes on the night of Duncan’s murder. While waiting for Macbeth to kill Duncan, she admits “Had he not resembled/ my father as he slept, I had done’t.” Again, she is portraying herself as ruthless and violent, but her action (or lack of action) tells a different story. Maybe she would have killed Duncan if he didn’t look like her father; maybe not – all we know is, given the opportunity to kill the king, she couldn’t go through with it. Her previous wish that her blood would “stop up th’ access and passage to remorse” has not come true. When Macbeth announces Duncan’s death, she faints. One reading is that her faint is faked to distract from Macbeth’s shaky story. But if the faint is real, it suggests she just now realizes the truth of what they’ve done, and is overwhelmed by her husband’s ability to kill not only Duncan but also the attendants, and lie so easily about it.
After Duncan’s murder, Lady Macbeth’s role is of comforter and protector of Macbeth, rather than instigator of murder, and her character becomes more sympathetic. Immediately after the murder, Macbeth says, “to know my deed, ‘twere best not know myself,” and the rest of the play sees him becoming further estranged from himself and his essential humanity. Lady Macbeth, in contrast, stops pretending to be someone she’s not, and begins admitting who she actually is. She recognizes the error of their actions, saying, “’Tis safer to be that which we destroy/Than by destruction dwell in doubtful joy.” They’ve killed Duncan, but the murder only made them miserable, and in some ways they’d be better off dead. However, she continues to put on a brave face for her husband, encouraging him to put the past behind him (“what’s done is done”) and stop worrying. When Macbeth sees Banquo’s ghost at the banquet, Lady Macbeth again covers for him. But, sensing her regret, he hides his plans to kill Lady Macduff and her children. Not only has Macbeth become a stranger to himself, he is also a stranger to his wife, who now has no ally and is isolated in her guilt.
The last time we see Lady Macbeth she is raving about blood on her hands, signaling that she is a victim of her husband and her own overwrought emotional state. Over the course of the play we’ve seen her evolve from a crafty manipulator to a guilt-ridden casualty of her husband’s ambition who has lost all agency over her own life. “The Thane of Fife had a wife. Where is she now?” she asks, in what sounds like babble but is actually a poignant acknowledgment of her own irrelevance. Her husband is off murdering more innocent people in his quest to hold onto his ill-gotten crown, while Lady Macbeth, who hoped to share in his glory, has been abandoned. Her obsession with cleaning the phantom blood off her hands signals that she has been just as tainted as Macbeth by his murders, even though she did not commit them herself, nor has she benefitted from them. While Lady Macbeth is far from blameless for her role in inciting her husband to action, she ends the play a far more sympathetic character than she began.