I don't even know what doublespeak and duality is.
Hey, this is a pretty big essay question. Hopefully I can give you something to go on. "Doublespeak" is also known as equivocation. It is sort of a double meaning on the surface almost a riddle. In the end the statements are really a paradox. Consider Macbeth's first line, "So foul and fair a day I have not seen". From there the double speek never stops coming. Much of it is given to Macbeth to convey a false sense of security, "till Birnam Wood be come to Dunsinane", "none of woman born shall harm Macbeth....." Macbeth believes what he wants to believe. The witches seem to know that he is weak minded, that reason easily falls victim to desire. Macbeth takes this duality of meaning and forces it to work in his life. This, of course, is his undoing.
