"You either die a hero or you live long enough to see yourself become the villain." Harvey Dent spoke these words in the 2008 adaptation of Batman: The Dark Knight. Dent is referring to such men who suffer from a shift of good to evil due to the power thrusted upon them. He is essentially saying that a person of authority will either die honorable or survive only to see themselves become morally diluted by ambition. Such a quote can easily be applied to Shakespeare's Macbeth as every central character met with power is eventually exacerbated by it. .
In Act 3 scene 1, Banquo reflects to himself, "Thou hast it now-King, Cawdor, Glamis, all/ As the Weird Sisters promised, and I fear/ Thou played'st most foully for't. Yet it was said/ It should not stand in thy posterity,/ But that myself should be the root and father/ Of many kings. If there come truth from them-/As upon thee, Macbeth, their speeches shine-/ Why, by the verities on thee made good,/ May they not be my oracles as well/ And set me up in hope?" This monologue represents an internal shift within the character of Banquo as he describes the witches' prophecy. It also alludes to the transformation Macbeth and Lady Macbeth undergo as well when ambition and the desire for power is brought into play. Earlier in the play the Weird sisters old Macbeth that he would become not only Thane of Cawdor, but the King of Scotland as well. Moreover, they also told Banquo that Kings would emerge from his family line. "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" (3.1). Unlike Macbeth, Banquo refuses to naively trust the menacing witches. He also thinks twice before blindly acting at their will, something Macbeth fails to do again and again. However, as the promise of power remains in the back of Banquo's mind he asks himself, "May they not be my oracles as well/ And set me up in hope?" It is almost as if Banquo is grasping at straws looking for some truth behind the Weird sisters' words.