The term hamartia was introduced in Aristotle's Poetics. According to Aristotle, the term refers to mistakes, sins, to err, and wrongdoings. Aristotle used this term to define a wrong committed against another person.
Over time, like many words, the meaning of hamartia has changed. Many critics have stated that Aristotle used the term wrongly in his text and that the true meaning of the word was more geared toward the err one commits when he/she does not know any better.
Aristotle's use of the word tended to lean towards the tragic flaw of a person based upon their own limits or weaknesses. While similar to that of alternative views, Aristotle's meaning encompasses that the flaw does not concede to the fact that the one in error is not wholly innocent and one cannot find him less morally at fault.
Hamartiais an error in judgement that arises because of the hero's tragic flaw. This error in judgement results in the tragic event, leading to the hero's downfall.
One example of hamartiais Brutus' convincing himself to help assasinate Caesar (in Shakespeare's Julius Caesar). This error in judgement (hamartia)is caused by his tragic flaw, being easily decieved, and this error in judgement leads to Brutus' eventual downfall and death.