How does Lady Macbeth persuade Macbeth to kill King Duncan?

Lady Macbeth persuades Macbeth to kill King Duncan by preying on his sense of manhood and courage. When Macbeth reveals that he has had a change of heart and is no longer willing to kill King Duncan, Lady Macbeth becomes enraged. She openly questions whether he is a man who is willing to act on his desires, asking, “Art thou afeard / To be in the same in thine own act and valor / As thou art in desire?” (1.7.39–41), and further calls his manhood into question by stating, “When you durst do it, then you were a man” (1.7.49). Lady Macbeth’s tactics work: Even though Macbeth is disgusted by his wife’s ruthlessness, he resolves to kill Duncan.