Find significant quotations from Act IV of Macbeth and explain the theme. Thanks!

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amarang9 eNotes educator| Certified Educator

In Act Four, Scene 1, after the witches have given their prophecies and disappeared, Macbeth asks Lennox if he had seen the witches. Lennox replies that he has not. Macbeth says, "Infected be the air whereon they ride, / And damned all those that trust them." (IV.i.154-55). He says this to let Lennox know he would not associate with such creatures. He says anyone that trusts them will be damned; this is fitting because their proclamations have encouraged Macbeth to engage in murder and tyranny. Despite what he says to Lennox, he has trusted what they've said. 

While Macbeth listens to poor advice, Lady Macduff refuses to listen to good advice. Both Macbeth and Lady Macduff are too stubborn at this point in the play. Lady Macduff is furious that her husband left her. When a messenger comes to warn her of approaching trouble, she refuses to leave. But she rightly asserts that it is silly for her to leave since she has done nothing wrong: 

                           Why then, alas, 

Do I put up that womanly defence 

To say I have done no harm? (IV.ii.77-79) 

Also, her quote right before these lines echoes the opening warning of the play from the witches who claimed that "Fair is foul, and foul is fair." Lady Macduff, noting the illogical reality of the world in which bad deeds are sometimes praised and good deeds are sometimes punished, sees no point in defending herself: 

                             But I remember now

I am in this earthly world, where to do harm

Is often laudable, to do good sometime

Accounted dangerous folly. (IV.ii.74-77) 

In a world where such things occur, Lady Macduff notes that it is pointless to defend herself, right or wrong though she might be. (Running with this theme in the play, Macbeth's sinful actions initially give him praise and rewards, but in the end, those actions ruin him.) 

Malcolm tests Macduff's loyalty by pretending to be sinful. Macduff continues to voice his support for Malcolm and his suspicions of Macbeth. This is another case where the fair become foul; that is, Malcolm, who is fair, pretends to be foul in order to make sure that Macduff is on his side. When he is assured Macduff is with him, he takes back his foul comments about himself: 

                                       but God above

Deal between thee and me, for even now

I put myself to thy direction and

Unspeak mine own detraction, here abjure

The taints and blames I laid upon myself 

For strangers to my nature. (IV.iii.121-26)