Lady Macbeth's speech makes clear the distinctions in the natures of men and women in Shakespeare's play. Women are portrayed as weak and gentle nurturers (such as Lady Macduff), whereas men are strong and quite capable of violence and cruelty. Knowing that Duncan will be murdered under her roof, Lady Macbeth prays to the invisible "murd'ring ministers" to eliminate from her nature all womanly attributes, such as compassion and pity. She asks that they "take my milk for gall," exchanging goodness and kindness for bitterness. She prays that they will ". . . fill me, from the crown to the toe, top-full / of direst cruelty!" Lady Macbeth seeks to lose all of her feminine "weaknesses" so that she can perform the horrible act that must be done to secure Macbeth the crown. Lady Macbeth intends to murder Duncan herself. Later, she discovers that she can't because as Duncan sleeps, he looks much like her father. This was either an excuse, or she wasn't as "unsexed" as she hoped to be.