How does "Macbeth" explore the balance of power between the conscience and the human capacity for evil?
"Macbeth" is a play about what happens when ambition is allowed to overpower reason and morality. Macbeth is ambitious, but in the beginning his ambition and desire for power is tempered by his morals. He doesn't want to commit murder in order to fulfill the weird sisters' prophecy. It doesn't take a lot of convincing from his wife, however, to get him to change his mind and decide to kill Duncan. Why does Macbeth fall to Lady Macbeth's will so easily? She appeals to his manhood; his basic sense of power. Later, when Macbeth returns to the witches, they use his desire to maintain his power (his hold on Scotland's throne) to lead him to feel invulnerable to attack. He's so filled with his lust for power and paranoia about being able to hang on to that power that he easily decides to kill Macduff's family when the first apparition tells him to beware Macduff. Then, that same lust for power makes him blind to the witches' trickery. That blindness leads to Macbeth's death. So, it comes down to the balance of power between the human conscience and the capacity for evil being tipped toward the capacity for evil. Macbeth's ability to be evil overpowered his conscience.