What does Banquo say about the motives of the "instruments of darkness" in Shakespeare's Macbeth?
The "instruments of darkness" Banquo refers to are the witches who cross paths with Macbeth and Banquo after the men have played a major role in putting down the rebellion against Duncan, their king. The witches promise Macbeth that he will be Thane of Cawdor and ultimately king, and that Banquo's descendents will be kings. This prophecy plants the seed of ambition in Macbeth, who begins to experience inner turmoil as the idea of killing his king, and thus hastening the prophecy, takes shape.
Banquo, in contrast to Macbeth, is less inclined to believe the witches and to trust their intentions. He voices his concern that the witches offer future glory, "tell us truths," only "to win us with honest trifles." Unlike Macbeth, he fears that these evil beings' predictions may indeed come true, but only as a way of snaring those whom they intend eventually "to betray's / In deepest consequence." Banquo sets himself apart from Macbeth here because he has the insight to see a trap in these prophecies.
In a play where "fair is foul" and appearance cannot be taken for reality, Banquo seems instinctively to know that the witches are using the truth in order to lure Macbeth away from his conscience. Their words will result in a deed so inconsistent with who Macbeth is at the beginning of the play that, after murdering Duncan, he will admit that he no longer knows himself.
"...'tis strange; and 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" (Act I, Scene iii, lines 122-126)
The "instruments of darkness" are the witches, and he is saying that sometimes they plant the idea of simple things that are or will be true for the purpose of bringing about our downfall. In Macbeth's case, the witches have called him Thane of Cawdor and King, prophesying to him that he will attain both titles. They are not telling him these seemingly innocuous facts. Instead, their motive is to instigate the sequence of events which will lead to his downfall. Once Macbeth has gotten the idea in his mind, his ambitions (and those of his wife) are kindled, and his basest nature shows itself as he begins to ruthlessly scheme to make sure the witches' predictions do indeed come true.
Banquo says, "Oft'times to win us harm the instruments of darkness tells us truths...to win us with honest trifles.. to betray in deepest consequence.."
This comment given by Banquo is very ironical in the drama."The instruments of darkness",represented by the witches,gives three predictions to Macbeth.One greets him with his present title,The thane of Glamis.The second greets him with the title,which though he does not know it,has already been given to him.Therefore,this one truth given to him by the witches in order to lure him to temptation suceeds in trapping Macbeth in their net.Because of this one truth given to him,Macbeth begins to believe in the witches,and they,true to Banquo's warning,betray Macbeth and lead him to his doom.
Banquo says that "Oft'times to win us harm the instruments of darkness tells us truths...to win us with honest trifles.. to betray in deepest consequence.."