His ambition
Explanation:
Many scholars see Macbeth as a villain instead of a hero because of his vile actions. But, a tragic hero can be either a protagonist or an antagonist. The key is that the audience can empathize with the character. Look again at the example of Michael Corleone. Many of us do not approve of mob violence and crime, but we can empathize with Michael when he loses his family members. The same can be said for Macbeth. We can empathize with Macbeth because he has been persuaded to commit certain crimes by his wife. Have you ever been persuaded by a person who you care for to do something that you feel is not right? That was Macbeth's situation.
So what else makes Macbeth a tragic hero? Macbeth is named the Thane of Candor and Glamis by King Duncan. Duncan refers to him as 'Noble Macbeth,' so the audience is aware of Macbeth's noble stature in the first act of the play.
When Macbeth visits the witches, they tell him that he is to be king of Scotland. At first, he rejects the idea, which contributes to his greatness: 'This supernatural soliciting cannot be ill, cannot be good.' He is fearful of the witches' prophecies because two of them have come true so far. He was not aware of the death of the Thane of Candor and that the king had named Macbeth as his successor. When he finds out that this is true, he is frightened and wonders how he will be named king.
Macbeth's loyalty to his king also indicates his greatness. When Lady Macbeth suggests that he assassinate the king, he replies: 'First, as I am his kinsman and his subject, strong both against the deed; then, as his host, who should against his murderer shut the door, not bear the knife myself.' Macbeth has indicated that he is content with his new title of Thane of Candor, but his curiosity as to how he will be made king is still eating away at him.
Ultimately, Macbeth's fatal flaw is pride that leads to wild ambition.
