Final answer:
Banquo expresses skepticism about the witches' predictions, suggesting that they might use truths to mislead and entrap Macbeth. He recognizes the potential manipulative nature of these 'instruments of darkness' and remains cautious about the witches' intentions.
Step-by-step explanation:
In William Shakespeare's play Macbeth, Banquo is indeed leery of the witches' predictions. When the witches hail Macbeth with his new titles, including that of Thane of Cawdor, which has not yet been announced, Banquo questions the reliability and intentions of these 'instruments of darkness'. He suspects that they may be using truthful revelations to entice Macbeth into a trap for more malevolent purposes. In the play, Banquo says:
The instruments of darkness tell us truths,
Win us with honest trifles, to betray's
In deepest consequence.
Here, Banquo hints at the notion that the prophecies might be a mix of truths and lies, designed to plant seeds of ambition that could lead to one's downfall. He is wary that these prophecies could be manipulative and ultimately ruinous, unlike Macbeth, who is quickly captivated by the idea of becoming king.