A question Shakespeare explores through Macbeth is one of predestination; Macbeth's life seems to be controlled by fate, but how much of Macbeth's story was foretold, and how much was of his own making?
Even when no one suspects him of foul play, Macbeth is troubled and cannot enjoy the life he sacrificed his immortal soul (what Christians believed lived on after death and went to Heaven or Hell) for