"Authority poisons everybody who takes authority on himself" (Vladimir Ilyich Lenin), this quote applies to the play, Macbeth. In the play, Macbeth kills the respected King Duncan so that he can be king. However, during his rule, Macbeth demonstrates that he is incapable of mastering the power and responsibilities of being a king. His drive for power and maintaining his power is the source of his downfall. Macbeth is not meant to have authority beyond Thane of Cawdor. When Macbeth is king, he does not use his authority judiciously. Macbeth's eventual demise is by virtue of his obsession for power and retaining his power.