Lady Macbeth believes wholeheartedly that the King must die, from as soon as she is aware of the witches’ prophecy. After reading Macbeth’s letter to her, Lady Macbeth is certain that her husband “shalt be what [he] art promised”. However she also believes that her husband is “too full of the milk of human kindness to catch the nearest way”. Lady Macbeth feels that Macbeth is overly nice, and that this will stop him being able to seize the crown. She feels that the only way for the pair of them to become monarchs is to “play false”, to do the wrong thing. Throughout her speech that succeeds the letter reading, Lady Macbeth references the need to do something evil in order to achieve the crown. Later in the same scene, when she and Macbeth are reunited, they discuss the fact that King Duncan will be coming to their castle that evening. Making it perfectly clear that she believes Duncan must be killed, Macbeth’s wife tells him that Duncan “never shall sun that morrow see”; King Duncan won’t live to see another day.
Lady Macbeth deliberately stops any chance Macbeth had of not killing Duncan through manipulation. Shortly prior to killing King Duncan, Macbeth is having serious doubts about committing the act. The title character almost conclusively decides that he will not kill the king, stating to his wife “we will proceed no further in this business”. However before he can walk away without committing the murder, his wife enters the room where he was having his moral dilemma. Lady Macbeth uses various manipulative approaches towards her husband to convince him to commit regicide. First off, Lady Macbeth accuses her husband of being a “coward” and tells him that “From this time, Such I account thy love”. Macbeth manages to deflect this personal attack. After this, Lady Macbeth states that if she had made such a promise as Macbeth has made to her, she would sooner “[dash] the brains out” of her own child as “it was smiling in [her] face” than break such strong a promise. Macbeth then worries that the plan will fail, but Lady Macbeth strongly convinces him that if he is courageous enough, they can’t fail. By manipulating her husband with such intent, Lady Macbeth further proved herself to be responsible for King Duncan’s death