Doppelgangers, Macbeth and Lady Macbeth reverse their roles in Shakespeare's play. For, while Macbeth exhibits courage and fearlessness on the battle field as he "carved out his passage" (1.2.19) until he brutally "unseamed his enemy" Macdonwald, Macbeth is hesitant about acting upon the predictions of the three witches who foretell his future as king. It is Lady Macbeth who, having called upon the evil spirits to unsex her, urges Macbeth to murder Duncan and hasten the future.
Before Macbeth does commit regicide, he has visions of a bloody dagger before him, and afterwards, he hears voices crying, "Macbeth hath murdered sleep." Hearing this, Lady Macbeth, who claims that she could have killed Duncan had he not resembled so her father, chides Macbeth for his weakness,
My hands are of your color, but I shame
To wear a heart so white....
A little water clears us of this deed:
How easy it is then! your constancy
Hath left you unattended....(2.2.)
Having told Macbeth that his firmness of purpose has left him, ironically, Lady Macbeth, later loses her aplomb as she imagines blood upon the stairs to her chambers. In her guilt, she perceives blood even on her hands, as well, and water will not clean them as she has told Macbeth:
What, will these hands ne'er be clean? No more o'that, my lord, no more o'that! You mar all with this starting (5.1)
And, thus, the guilt is transferred to Lady Macbeth while Macbeth continues upon his murderous path. Now a weakened creature, Lady Macbeth is no tragic figure, only a piteous one while Macbeth, in his "vaulting ambition," does not discern the true meanings of the witches' predictions. And, so, it is not so much these predictions, but the attempts to accelerate destiny that create the monsters of guilt and desperation.