Despite her guilt driving her to madness, Lady Macbeth is the original motivator of Macbeth’s actions. She tells him to “Look like th’ innocent flower, But be the serpent under’t” (-64). She wants him to hide his true ambitions and act like the noble person most believe him to be. She herself does her best to convince all that she is just as innocent as her husband pretends to be. After Duncan’s murder, the other noblemen in Macbeth’s home are questioning as to who the perpetrator really is, and Macbeth begins to nervously and guiltily ramble. In order to draw attention away from him, Lady Macbeth pretends to faint. She causes the men to think of her as a weak woman, changing their perception of her and creating a distraction.
Macbeth commits subsequent murders with less agitation than that of Duncan; but this is no inconsistency in his character; on the contrary, it confirms the principles upon which it is formed; for, besides his being hardened to the deeds of death, he is impelled by other motives than those which instigated him to assassinate his sovereign. In the one he sought to gratify his ambition; the rest are for his security; and he gets rid of fear by guilt, which, to a mind so constituted, may be the less uneasy sensation of the two. The anxiety which prompts him to the destruction of Banquo arises entirely from apprehension. For though one principle reason of his jealousy was the prophecy of the witches in favour of Banquo's issue, yet here starts forth another quite consistent with a temper not quite free from timidity. He is afraid of him personally; that fear is founded on the superior courage of the other, and he feels himself under an awe before him; a situation which a dauntless spirit can never get into. So great are these terrors that he betrays them to the murderers. As the murder is for his own security, the same apprehension which checked him in his designs upon Duncan, impel him to this upon Banquo.