Lady Macbeth as the Fourth Witch in Shakespeare’s Macbeth

 

Introduction
Although Shakespeare’s Macbeth explicitly presents three witches—the Weird Sisters—the idea of a symbolic “fourth witch” has long intrigued critics and readers. This concept does not refer to an additional supernatural character but to a human figure who absorbs, interprets, and operationalizes the witches’ influence. Lady Macbeth most convincingly fulfills this role. Through her language, invocation of dark forces, manipulation of prophecy, moral inversion, and psychological dominance, Lady Macbeth functions as the human extension of witchcraft within the play. She transforms supernatural suggestion into deliberate action, making her the most effective agent of evil in Macbeth’s early acts.
1. Invocation of Spirits and Ritualistic Language
Lady Macbeth’s first soliloquy (Act I, Scene v) marks a decisive turning point in the play and establishes her witch-like identity. Upon reading Macbeth’s letter, she immediately calls upon “spirits / That tend on mortal thoughts” to strip her of feminine qualities and fill her with cruelty. This invocation closely resembles a ritual summoning, aligning her speech with the incantatory language of the Weird Sisters.
Her plea to be “unsexed” places her in a liminal state, neither fully female nor male—much like the witches, whose beards confuse gender categories. In early modern England, witches were often depicted as transgressors of natural order, particularly gender and maternity. Lady Macbeth’s rejection of motherhood—“take my milk for gall”—directly echoes cultural associations between witchcraft and the corruption of maternal nurture. This linguistic and symbolic alignment strongly supports her identification as a fourth witch.
2. Interpreter and Executor of Prophecy
The Weird Sisters predict Macbeth’s rise but provide no instructions. Their power lies in suggestion, not execution. Lady Macbeth fills this crucial gap. She becomes the interpreter of prophecy, translating ambiguous supernatural predictions into a concrete plan of action.
While Macbeth hesitates, reflecting on moral, political, and spiritual consequences, Lady Macbeth reframes murder as destiny. She insists that fate must be assisted, thereby collapsing the distinction between prophecy and action. In doing so, she performs the witches’ work more decisively than the witches themselves. Without Lady Macbeth, the witches’ predictions might have remained unrealized possibilities.
Her role here mirrors the witches’ logic of inevitability. By persuading Macbeth that kingship is already ordained, she absolves him—at least rhetorically—of moral responsibility. This manipulation is a central reason she is considered the fourth witch: she converts supernatural temptation into human crime.
3. Moral Inversion and Witchlike Ethics
Lady Macbeth consistently employs moral inversion, a defining feature of witchcraft in Macbeth. Like the witches’ mantra “fair is foul, and foul is fair,” Lady Macbeth urges deception and duplicity. She advises Macbeth to “look like the innocent flower, / But be the serpent under’t,” promoting a worldview in which appearance and reality are deliberately misaligned.
She regards Duncan’s virtues not as moral safeguards but as weaknesses to be exploited. Compassion, hospitality, and loyalty—cornerstones of social order—are dismissed as obstacles to power. This inversion of ethical values mirrors the witches’ subversion of natural and moral law and reinforces Lady Macbeth’s symbolic association with them.
4. Psychological Control and Witchlike Manipulation
Another reason Lady Macbeth is called the fourth witch is her psychological dominance over Macbeth. Rather than using spells or potions, she employs verbal coercion, emotional manipulation, and strategic shaming. By questioning Macbeth’s masculinity and courage, she destabilizes his identity, pushing him toward action.
This form of manipulation resembles witchcraft as it was culturally imagined in Shakespeare’s time—not merely as magic, but as persuasive, corrupting influence. Lady Macbeth casts no literal spell, yet her words exert a transformative power over Macbeth’s will, making her influence as effective as any supernatural enchantment.
5. Contrast with the Weird Sisters: The Limits of Human Witchcraft
Despite these parallels, Lady Macbeth’s eventual breakdown distinguishes her from the actual witches. The Weird Sisters remain untouched by guilt, while Lady Macbeth is consumed by it. Her sleepwalking scene reveals the return of repressed conscience, as she compulsively reenacts the crime she once dismissed.
This collapse highlights a crucial thematic distinction: Lady Macbeth may act as a fourth witch, but she remains human. Her psychological disintegration underscores Shakespeare’s suggestion that human agents who assume supernatural authority cannot escape moral consequence. In this sense, her tragedy reinforces the play’s ethical framework.
6. Feminist and Cultural Implications
From a feminist perspective, Lady Macbeth’s association with witchcraft reflects early modern anxieties about female agency. Women who sought power beyond domestic roles were frequently demonized as unnatural or diabolical. Shakespeare draws on this cultural fear while also exposing its cruelty. Lady Macbeth’s resort to witch-like power arises from structural exclusion rather than inherent evil.
Thus, calling Lady Macbeth the fourth witch does not merely label her as villainous; it reveals how patriarchal society pathologizes female ambition by aligning it with the supernatural.
Conclusion
Lady Macbeth is called the fourth witch because she embodies, internalizes, and executes the witches’ influence within the human realm. Through ritualistic language, manipulation of prophecy, moral inversion, and psychological domination, she becomes the practical agent of evil that the Weird Sisters merely suggest. Yet her ultimate collapse reveals the limits of human transgression and reasserts the moral cost of ambition without restraint.
Shakespeare ultimately suggests that the most dangerous witchcraft is not supernatural magic, but the human capacity to rationalize evil and silence conscience.