In a play obsessed with "the seeds of time" and the "line of kings," the most powerful agents of fate are conspicuously outside the cycle of biological reproduction. The Three Witches, or [Weird Sisters](https://en.wikipedia.org/wiki/Three_Witches), represent a specific form of sterility that is not merely a biological defect, but a profound metaphysical choice. They embody a perversion of the feminine that suggests that to possess their level of supernatural agency, one must exist entirely outside the generative order of nature.
## The Physical Evidence of "Unsexing"
We know the witches are sterile—or at least effectively "unsexed"—primarily through the observations of Banquo. Upon first encountering them in Act 1, Scene 3, Banquo struggles to categorize them within the human or gendered spectrum. Their physical appearance suggests a withered, liminal state that denies the possibility of motherhood or sexual vitality.
> "You should be women, / And yet your beards forbid me to interpret / That you are so." (Banquo, *Macbeth*, 1.3.45-47)
This "androgyny of evil" is a recurring motif in early modern demonology. By possessing beards, the witches disrupt the binary necessary for reproduction. In the Elizabethan worldview, the "natural" role of the female was the production of heirs; by existing as "secret, black, and midnight hags," they have traded their procreative potential for a destructive, prophetic power.
## Extractive vs. Creative Power
The sterility of the witches is further confirmed by their relationship to infants and birth. In Act 4, Scene 1, their cauldron is filled not with life-giving ingredients, but with the remnants of failed or destroyed generation. They utilize a "finger of birth-strangled babe / Ditch-deliver'd by a drab." This choice of ingredient highlights their status as predators upon the reproductive process.
Scholars like [Janet Adelman](https://en.wikipedia.org/wiki/Janet_Adelman) in her seminal work *Suffocating Mothers* argue that the witches represent a displacement of the maternal. In this framework, their sterility is essential to their role as "anti-mothers" who provide Macbeth with "prophetic food" that ultimately leads to his starvation and death. Unlike Banquo, who is "lesser than Macbeth, and greater" because he will "get kings," the witches and Macbeth are dead ends.
## Thematic Implications of Barrenness
The witches' sterility sets the stage for the play’s broader exploration of the "barren sceptre."
- **The Anti-Generative:** The witches do not create; they only unravel. Their magic is fundamentally reductive.
- **The Contrast with Lady Macbeth:** While the witches are inherently sterile, Lady Macbeth must actively pray to be "unsexed" and have her "milk for gall" exchanged. The witches represent the final, realized state of that which Lady Macbeth only attempts to achieve.
- **The Failure of Lineage:** Because the witches have no past and no future (no parents, no children), they are the perfect catalysts for a man who seeks to freeze time and rule a kingdom of ghosts.
If the witches are indeed sterile, we must ask: is their power derived *from* their barrenness? In the world of *Macbeth*, it appears that to transcend the mortal "tomorrow, and tomorrow, and tomorrow," one must first sever the link to the next generation.