What is the relationship between Macbeth and cosmic justice?
Macbeth is an example of the fulfillment of cosmic justice. The end of the play, when Macbeth is rightfully killed by Macduff for all his atrocious deeds, suggests that justice has been satisfied.
Macbeth, of course, believes that he has been tricked and that others are to blame for his downfall. In one of his famous soliloquies, Macbeth adopts a bleak view on life and states that life is meaningless:
It is a tale
Told by an idiot, full of sound and fury,
What Macbeth does not realize is that he is solely responsible for making his life meaningless and revolting. Once he resorted to unlawful means in order to achieve his ambition of becoming the king of Scotland, he initiated his own downfall.
The message that this play seems to convey is that one's actions matter. Actions define who we are and are our responsibility only. If Macbeth were not punished for his crimes at the end of the play, the play would seem to suggest that resorting to evil could be one effective way to achieve the things we desire, which is unacceptable. Those who do evil will be punished for it sooner or later.