What did Aristotle call harm aria according to the play julius Caesar

I'm not sure what you mean by "harm aria".

Hamartia is a person's fatal flaw basically. In this case, Caesar's fatal flaw is his ignorance and greed for power. His own belief that he is high and mighty eventually leads to his death. Sure, he refused the crown 3 times but that was just a show to see if the people really wanted him to be king. When someone (Decius, I believe) brings up the fact that he is to be crowned king right after he promised Calpurnia that he was not going to go, he doesn't hesitated to take the chance. This is what ultimately brings his death because it was all a trap, and he fell right into because of his vanity.