"Character is fate." How far does Macbeth bring out his own destiny?

From the beginning of the play, when the audience is introduced to the character of Macbeth, they are also introduced to his weakness: his susceptibility to witchcraft. As the "noble" and "valiant" Macbeth transforms from a good Cawdor to an evil king.
Shakespeare does not make it clear whether Macbeth freely chooses his path on his own or is controlled by the witches. It is evident from the opening scenes of the play that he is particularly affected by the supernatural, when Banquo asks Macbeth why:
"You start and seem to fear…"
Macbeth's reaction to the supernatural should b…