Review Question 1: The Witches

I would say that the witches want to meet with Macbeth so that they can get him to feeling power hungry.  They do this by telling him some major events that will take place in his life.  Once the first event takes place Macbeth feels like he must make the other events happen immediately, leading to his death.  So I would say that the witches bring on his death, but then again maybe not because it sure seems like Macbeth and his wife are quite evil.  He might have done the same exact thing even if he didn't meet the witches.