Macbeth falls further into evil when he does more than what he and his wife had planned: he kills the two guards guarding Duncan’s bedroom. He tries to defend his killing of them in Act 2 Scene 3: “Macbeth: There the murderers, / Steeped in the colours of their trade; their daggers / Unmannerly breeched with gore. Who could refrain, / That had a heart to love and in that heart / Courage to make’s one love?” This shows Macbeth’s plunge into evil as he murdered the two guards without any of his wife’s influence; he murdered them out of his own will.
Macbeth sinks even further into evil after he becomes king. First of all, he attempts to kills Banquo, his friend, and his son Fleance just because he doesn’t want Banquo’s descendants to become kings after him. This, like the murder of the two guards, was done without the influence or knowledge of Lady Macbeth. Macbeth even hires two murderers in Act 3 Scene 1 (one more in Act 3 Scene 3) to do his dirty work for him: “Macbeth: This I made good to you in our last conference; passed in probation with you how you were borne in hand” This shows Macbeth telling the Murderers that in their last meeting that Banquo was their enemy and he deceived them.
Macbeth sinks further into evil when he tells his wife that “blood will have blood” and that he has “Stepped in so far that should I wade no more, / Returning were as tedious as go o’er” after he sees Banquo’s ghost. This shows that Macbeth has killed so many people that he cannot turn back but can only go on, so therefore he will kill anyone who poses as a threat to him.
Macbeth next sinks into evil when he meets the Witches for the second time in Act 4 Scene 1. The second apparition falsely assures Macbeth that he cannot be harmed by anyone: “Be bloody, bold, and laugh to scorn / The power of man, for none of woman born / Shall harm Macbeth.” The third apparition tells Macbeth that he cannot be defeated until Burnham Wood comes to Dunsinane: “Macbeth shall never vanquished be until / Great Burnham Wood to high Dunsinane hill / Shall come against him.” Both of these apparitions make Macbeth think that he can do whatever he want and get away with it, as he falsely believes that he cannot be killed or defeated.
Macbeth next sinks even deeper into evil when he decides to murder all of Macduff’s family. He does this when he hears the Witches first apparition: “Macbeth, Macbeth, Macbeth: beware Macduff / Beware the Thane of Fife. Dismiss me. Enough” and in response to hearing that Macduff has fled to England to raise an army against him. He then says in his soliloquy that “The very firstlings of my heart shall be / The firstlings of my hand.” This shows that Macbeth has now sunk into evil enough that when he thinks of someone to murder he will immediately arrange for them to be murdered.
Finally, Macbeth’s attitude to Lady Macbeth later in the play adds to Macbeth’s increasing villainous and evil nature. Macbeth asks the Doctor in Act 5 Scene 3: “How does your patient, doctor?” This shows that Macbeth has dominated over his wife, unlike in the first two scenes, and calls her “patient” rather than “wife”. Also, when Macbeth hears about his wife’s death, he blandly says “She should have died hereafter.” This shows that Macbeth doesn’t care as much about his wife than in earlier on in the play and just says that she should have died at another time.
In general, Macbeth has started off as a successful warrior and loyal subject to Duncan then has murdered his way to the Scottish throne and then murders anyone he suspects to be a threat. His attitude towards Lady Macbeth changes: from being persuaded by Lady Macbeth to commit murder to murdering without his wife’s influence and neglecting her as a partner especially when she mentally breaks down. This shows Macbeth’s plunge into evil and every murder he commits he falls deeper and deeper into it.