Lady Macbeth is perhaps the most remarkable character in Macbeth. She is profoundly ambitious, and once she learns of the weird sisters' prediction that Macbeth will become king, she sets out to encourage him along the way, since she doubts if he will have the wherewithal to fulfill his destiny himself. To this end, she persuades her husband to murder Duncan, and indeed determines the time and place where it will happen. Her chilling speech in Act I, Scene 5, is an expression of pure evil.
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!
Scholars have long focused on this passsage to argue that Lady Macbeth was intended to be an archetype of feminine treachery. Yet she is tormented by her husband's actions once he has actually carried them out (as revealed in the famous "out, damned spot!" speech,) and she eventually commits suicide. Recently critics have pointed out that Macbeth alone is responsible for his actions, especially in the patriarchal setting of Macbeth, and have emphasized her unquestionable love and devotion to her husband. While this bond is ultimately shattered by their evil acts, it also contributes to a more complex view of one of Shakespeare's greatest villains.