Idea: The phrase employs a paradox, as it foreshadows the deception of Macbeth, in that the prophecies of witches might lead him to greatness, but they would destroy him instead. The witches are symbolic of foul, but give fair advice. Macbeth outwardly appears to be a hero, but inwardly he is a coward and twists the witches' words. Shakespeare establishes the disruption of the natural order and the corruption of nature through the use of paradoxical language and parellism.