Explain the character of Macbeth and how/why he changes.

Macbeth's most important character trait is his ambition. Ambition, in and of itself, stands as value neutral. It can either lead to positive results by motivating a person to work harder to attain higher achievements or can lead to negative outcomes by motivating one to put personal gain ahead of ethical or moral considerations. As the play opens, we realize Macbeth is ambitious because of his excitement about the witches' prophecy that he will be...

Macbeth's most important character trait is his ambition. Ambition, in and of itself, stands as value neutral. It can either lead to positive results by motivating a person to work harder to attain higher achievements or can lead to negative outcomes by motivating one to put personal gain ahead of ethical or moral considerations. As the play opens, we realize Macbeth is ambitious because of his excitement about the witches' prophecy that he will be king. He is also pleased to be named Thane of Cawdor by King Duncan. In fact, one of his reasons for not wanting to kill Duncan is to bask in the glow of that achievement. Despite his high level of ambition, Macbeth draws back from murdering the king, feeling on second thought that it would be a great wrong to do so, especially since Duncan is his guest. This shows that Macbeth still takes moral considerations into account. He has to be goaded into the act of murder by his wife.

However, once Macbeth crosses the line and kills the king, an act considered to be of even greater evil than it would be now, for Macbeth murdered God's anointed ruler and a just and "meek" (merciful) one at that, he loses his moral compass. It's as if once he murders, he no longer knows how to practice restraint. He becomes ever more blood-soaked as he eliminates rivals, and he transforms into a tyrant whose countrymen begin fleeing. His land is threatened with anarchy and chaos, causing the English king to raise an army to intervene. Evil leads to more evil.

On one level, Macbeth could be read as a treatise on good kingship. In Shakespeare's telling, the good king is chiefly pure, virtuous and self-controlled enough to put others' interests ahead of his own--attributes that Duncan had and the English king possesses in great measure. Macbeth, however, by putting his own ambitions ahead of the good of the realm, has sacrificed any hope of becoming a viable monarch.