Final answer:
Macbeth's tragic flaw is his ambition and susceptibility to external influences, and he is somewhat aware of this flaw as he reflects on his actions throughout the play.
Step-by-step explanation:
Macbeth's tragic flaw is his ambition, coupled with the susceptibility to external influences, particularly from his wife, Lady Macbeth, and the witches.
Conceivably, he is aware of his flaw, especially when reflecting on his actions, as he notes how his ambition made his will 'the servant to defect'.
Macbeth's ambition and his subsequent actions reflect the classic elements of a tragic hero, where his flaw leads to his downfall.