I think That Banquos part in the play is to contrast Macbeths character and decisions. Banquos loyal, honourable and heroic character matches that of Macbeths at the beginning of the play but as Macbeth changes into the evil, over ambitious “Butcher” later on in the play, Banquo remains an honourable and loyal soldier. This highlights the change in Macbeths character stage by stage because Banquo can be used as a comparison and can be looked back upon to compare Macbeths original character to his present one showing how much he has changed.
Banquo has a lack of ambition through out the play, He appears to be content with his status and willingly accepts his level in the “natural order” . When Macbeth and Banquo meet the witches, Banquo seems suspicious of the witches. Unlike Macbeth he has no hidden ambitions. Banquo has no intension of perusing the prediction that his sons will be kings and is happy to discard the witches comments. He says “oftentimes to win us to our harm the instruments of darkness tell us truths, win us with honest trifles, to betray’s in deepest consequence” This shows Banquos understanding of the witches, he will happily discard what the witches have said because he knows that the truths they tell can be a means of trickery. Banquo does think that the prophecies might come true but doesn’t feel he needs to encourage them and is happy to leave it to fate. This is an opposite reaction to Macbeths. Macbeth immediately has thoughts of treason and doesn’t even begin to imagine that maybe the prophecies can come true by fate.
Banquo also has integrity and a conscience. Unlike Macbeth he can distinguish between right and wrong/good and evil. He can see that the witches are evil and understands the danger involved with believing what they say. He warns Macbeth of this when he notices that he is “rapt” by them. When it is announced that Macbeth will become thane of Cawdor Banquo says :What, can the devil speak true?” This shows that Banquo sees the witches premonitions as the words of the devil. The thoughts of murder and treason don’t enter Banquos train of thought as they do Macbeths, Banquo is troubled by the witches “ I dreamt last night of the three weird sisters” He appears to be worried about the prophecies and his conscience makes him feel almost guilty for thinking of them again, but shows integrity when he tells Macbeth about his troubled sleep. He also shows this after hearing of Duncan’s death, He is genuinely shocked and upset by the news “too cruel, anywhere. Dear duff, I prithee, contradict thyself, and say it is not so”. From this point he does believe the witches but still vows not to peruse or encourage them “may they not be my oracles as well, And set me up in hope?” This shows that Banquo has a conscience and wouldn’t begin to consider encouraging something that is obviously evil unlike Macbeth, who’s ambition takes over blocking his wider view. This contrast of character is used to emphasize Macbeths evilness.
