In the opening scenes of Macbeth, Macbeth and Banquo come across the three witches, or the "weird sisters," who prophesy that Macbeth will become first the Thane of Cawdor and then the King. Macbeth at first doubts the sisters, but then learns that he has become the Thane of Cawdor by chance and wonders if the prophesy of him becoming King will also come true. One argument might ask whether the weird sisters prophesied and therefore caused Macbeth's actions by putting the seeds of bloodshed into his mind, or if Macbeth's choices were free, making him responsible for them. Put simply, are the witches responsible for Macbeth's actions, or is Macbeth?
One central question of the play is whether or not Macbeth's actions are fated or if he brings about his own demise through his ambition. If Macbeth is fated to be the Thane of Cawdor and then the King, did he have a choice in his actions? Could he have had the same fate, only in a positive way, if he had not given in to his ambitions? This argument topic could ask if Macbeth was fated to act the way he did or if he was free to choose otherwise. Did fate make Macbeth act, or did his own ambition?
Macbeth seems unwilling to act to bring forth the prophesy until Lady Macbeth, hearing of the prophesy, urges him to act to bring it to fruition. In Act 1, scene 5 of the play, Lady Macbeth says that she fears that Macbeth is too "full of the milk of human kindness" to do what she believes needs to be done. Lady Macbeth believes that fate needs to be helped by action. As a towering figure, one of great will and convincing rhetoric, Lady Macbeth is a difficult person to argue with. Is Lady Macbeth, who seems to think up most of Macbeth's evil deeds, the one really responsible and "in control" of Macbeth's actions?
The final argument around free will involves Macbeth's status overall: is he the villain of the play or a victim of Lady Macbeth, fate and the witches? If he is a victim, does that mean that he doesn't have free will after all?