Aristotle is known widely for developing his ideas on tragedy. He recorded these ideas in his Poetics in which he comments on the plot, purpose, and effect that a true tragedy must have. The structure of these tragedies has been an example for many writers including Shakespeare himself. Many of Shakespeare's plays follow Aristotelian ideas of tragedy, for instance Macbeth does a decent job in shadowing Aristotle's model.
Aristotle describes one of the most important elements of a tragedy to be a tragic hero. The tragic hero however must present certain qualities such as nobility and virtue. In the play Macbeth, Macbeth is a perfect example of a tragic hero. Macbeth begins the play coming home from battle, he is said to have fought with great courage and King Duncan himself awards him the title of the thane of Cawdor in reward for his bravery. The qualities make Macbeth a tragic hero as he possesses not only a noble title, but also the assets of a great warrior and hero.
However, Aristotle emphasizes that if the tragic hero was as perfect as he seems than the audience would not be able to identify with him and this would not be considered a tragedy. Macbeth shows us his humanity very early in the play when he learns that Malcolm, Duncan's son, will be the heir to the throne of Scotland. In response, Macbeth acknowledges that he himself should be awarded the crown and will not rest until royalty is his. Macbeth is an ambitious character, which is a quality that many humans can identify with. This ambitiousness is known as Macbeth's tragic flaw.