In his book Witches & Jesuits: Shakespeare’s Macbeth (The New York Public Library: Oxford University Press, 1995), Garry Wills argues that Shakespeare presents two dramatically different aspects to Lady Macbeth’s character in Macbeth, both of them drawing upon Witch-Tropes familiar enough to the Jacobeans so as to create a frisson for his audience that we might miss today.
Once Lady Macbeth and her husband conceive of killing King Duncan (so that Macbeth can become King), they both apply themselves to the idea with gusto (as suggested, for instance, in John Singer Sargent’s 1889 portrait of the famed 19th century actress Ellen Terry in the part, seen to your left). Lady Macbeth exhibits such brio, that she immediately devotes herself to a speech “psyching herself up” for the regicide- a speech that imitates so closely a Witch’s Invocation that Shakespeare’s audience must have felt a thrill of dangerous excitement run down their spines as she spoke. To the Jacobeans of the early 17th century, Magick-Use (onstage or in person) was a Thing of great potency, and something with which a cautious person will demonstrate enormous care. For the Thane’s Lady to devote herself to murder, and the royal murder of a King, by calling upon “Murdering Spirits” of darkness and cruelty- this, to theater-goers of the 1600s, would be a dangerous, treacherous path indeed.
“The raven himself is hoarse, that croaks the fatal entrance of Duncan under my battlements. 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! Make thick my blood; stop up the access and passage to remorse, that no compunctious visitings of Nature shake my fell purpose, nor keep Peace between the effect and it! Come to my woman’s breasts and take my milk for gall, you Murdering Ministers, wherever in your sightless substances you wait on Nature’s mischief! Come, thick Night, and pall Thee in the dunnest smoke of Hell, that my keen knife see not the wound it makes, nor Heaven peep through the Blanket of the Dark, to cry, Hold! Hold!”
[Enter Macbeth, her husband]
“Great Glamis! Worthy Cawdor! Greater than both, by the All-Hail hereafter!” [Act I, scene V, lines 40-56]
The speech, probably inspired by Medea’s Invocation to the Night in Ovid’s Metamorphoses (familiar to the 17th century English both through the Latin and the popular English translation), “mirrors” a Witch’s Speech so much, that the Witchcraft-Believing audience will start subliminally thinking of Lady Macbeth in terms of Witchcraft- if they do not start considering her as a Witch outright. (In the 2006 Australian film of Macbeth, the speech is delivered forthrightly as a Witch’s Invocation to the Full Moon.)
“The raven himself is hoarse”- the Lady’s first line calls to mind the proverbial Witch’s Familiar, still associated with Witches (see Disney’s Snow White and Disney Pixar’s Brave), and surely inherited from Celtic Raven-Goddesses such as the Morrighan. “Come, you Spirits that tend on Mortal thoughts”- this line is actually ambiguous, as it simply means, “You Spirits that know my thoughts”; basically what anyone Invokes, whenever they invoke Desire. Ah, but: “Unsex me here”; “Fill me up with cruelty”; “Stop up the access and passage of remorse.” Here the Lady is asking the Spirits to remove the (stereotypically feminine) soft, gentle aspects of her womanhood, and fill her with cruelty, blocking within her any twinges of misgiving and empathy that might trouble her killer’s conviction. “Come to my woman’s breasts and take my milk for gall”: Lady Macbeth goes on to demonstrate a troubling inclination to refer to her functions of maternity in horrific terms; here she wants “Murdering Ministers” to transform her milk to the bitter fungus gall. Like her husband, she calls forth the Darkness of Night to shroud their crime from detection. And lastly- “Great Glamis! Worthy Cawdor! By the All-Hail hereafter”- she imitates the Witches in their first meeting with Macbeth.
Both Macbeths will immediately begin to talk in Magickal-User terms, once they begin to plot the King’s murder (Macbeth will go so far as to adopt the language of a Master Magus when he joins the Witches in their Circle): they think that their Magickal terminology gives them power and control over their actions.
Ah- but when the Spirits That you are invoking are the “Murdering Ministers of dunnest [blackest] Hell”: how much control do you think you really have?
As the Macbeths discover: it is one thing to plan a murder; another thing to execute it. But to live with one’s conscience afterwards- that’s something else altogether.