A major literary device used in Shakespeare's Macbeth is paradox. A paradox is a situation that at first appears false but after some thought shows a significant truth. In the first scene of Act 1, the witches end their meeting by saying, "Fair is foul and foul is fair." At first, the statement seems false; however, as the events in the play unfold, it becomes clear that the statement is true: those who appear good and honorable are really ill at heart. King Duncan gives Macbeth much praise for fighting valiantly for Scotland--he calls him his "worthiest cousin" when he returns from battle. However, after Macbeth hears the witches' prediction, he cannot abandon his "blackest desires" and plots with his wife to murder Duncan and take the throne. So, Macbeth who appears to be good and honorable is really ill at heart as suggested by the paradox offered by the witches.