that they had on Macbeth, they could have just played him for his obvious ignorance, and they might have even had no idea that any of the events would happen. Macbeth and Banquo, upon learning of the previous thane's fate from the messenger, both marveled at the witch's apparent ability of prophesy, even though Macbeth had already been named the Thane of Cawdor. This influences the two men into believing that their other prophesies will come to pass, and in turn, spurs the rampant Macbeth into action, which causes him to fulfill his own predictions through his own free will, though influenced by the witches' suggestions of a possible kingship. Banquo himself even considered that the witches could be lying to tempt people into indulging in evil deeds when he clearly states,
             Might yet enkindle you unto the crown,
             ...