The main forces cause the downfall of Macbeth: supernatural and external. The three witches and the dark powers behind them represent the supernatural forces. Lady Macbeth is an external force that pushes Macbeth towards the bloody deeds. Macbeth eventually realizes that the witches have deceived and tricked him to cause his downfall. Macbeth's tragic flaw is his internal self that furthers his proximity to his end, by clouding his vision. Macbeth truly regrets his actions when he realizes the gravity of the situation. The Scottish King is essentially forced to commit the crime that leads to his downfall because of evil forces and his own tragic flaw.

The setting at the very beginning of the play is "A desert place. Thunder and lightning. Enter three witches." Shakespeare uses dark and light imagery to indicate that evil and supernatural forces are involved. The witches fool...