What is Macbeth's tragic flaw?

Answer 1

Macbeth's tragic flaw is not his ambition, although this has been a favourite platitude for centuries, and was actually written in as a line for Macbeth before he died by some well-meaning adapter.

"Vaulting ambition, which o'erleaps itself

And falls on the other."

(Macbeth, lines 27-28, Act 1 Scene 7).

These are lines spoken by Macbeth when deciding whether to commit the murder. He clearly holds ambition in contempt. His decision is that ambition is not a sufficient motive to kill Duncan and he tells his wife so. Nevertheless he is persuaded by her to commit the murder anyway. Once he is king (that's at the beginning of Act 3) none of his actions from there to the end of the play can be motivated by ambition, because he has as much as he can expect to get. There is nothing more to be ambitious for. What leads to his downfall is more his inability to say no to his wife, and his paranoia. Lady Macbeth, on the other hand, is moved by ambition, and she specifically comments on her unhappiness in finding that, having achieved her ambition, it has turned to ashes in her mouth. "Nought's had, all's spent, when desire is had without content."

Answer 2

Macbeth's tragic flaw was his vaulting ambition.