Although Macbeth does take actions that lead to his downfall, I believe that he is not totally responsible for what happens. Although he takes the action that leads to his downfall, he perhaps would not have done this if the witches had not told him that he would be king in Act 1 Scene 3. I believe that it is the witches are more responsible for Macbeth's downfall than he is. In Act 1, Scene 3, the witches tell Macbeth that he is thane of Glamis, thane of Cawdor and that he "shalt be king hereafter". Immediately after hearing the witches prophesise that he will be king, Macbeth thinks that he must kill the current king to become king himself. I believ