One of the major issues is how ambition can corrupt the individual. Lady Macbeth is the classic example of this. She desires power; she has more ambition than her husband. It should be noted that he is ambitious, but he hesitates to kill Duncan. He kills Duncan only through the encouragement of his wife.
The other theme in the play is the difference between being a true royal leader and a tyrant. Duncan is constantly referred to as a king in the play. However, Macbeth becomes a tyrant. The true attributes of a king are discussed; these include temperance, justice, and stability. Macbeth lacks these. He is emotionally unstable; he struggles with ambition. Afterwards, he struggles with his guilt. He is also not a just ruler. Macbeth is recognized as a temperamental and violent individual. This is seen in his willingness to engage in murder.
The play Macbeth by William Shakespeare indicates that people are often corrupted by ambition. Macbeth was most certainly corrupted by ambition. His lack of character that allowed this corruption also made him more likely to become a tyrant. Duncan was a leader.