Duncan and Macbeth's downfall in Shakespeare's play Macbeth results from their reluctance to question the motives and actions of others. It was that absolute trust, believing that no one would try to rise up against them, that foreshadows the murders of both characters. Duncan, the first to fall prey to over-confidence, trusted the Thane of Cawdor completely until he discovered that the Thane was a traitor who was betraying him. In Macbeth's case, he believed the prophecies of the three witches without realizing that they have ulterior motives ....