Evil is caused by many things but in Macbeth it is clear
that the Evil is caused by Lady Macbeth and Macbeth's need for power.
Lady Macbeth uses her persuasion and Macbeth's attraction to her as a
means of getting Macbeth to take the first step down the path of evil. In
the Epic Lady Macbeth constantly states "Are you a Man?", she states
this because she is attempting to cause internal struggle for Macbeth.
This internal struggle as well as his craze for power causes Macbeth to
take his first step down the path of evil. Along with motivation
for becoming evil, every person needs to have some event or action that
signifies them becoming evil. For Macbeth it was his murdering Duncan.
Him killing Duncan as well as the two guards shows that Macbeth is evil
because he killed one of his best friends as well as two other men whom trusted
him.
After this murder Macbeth is wracked with guilt, he states "Will all great Neptune’s ocean wash this blood / Clean from my hand? No". These lines are used to to show that Macbeth's conscious is filled with guilt of murdering King Duncan, yet when he causes the death of Banquo Macbeth doesn't speak of guilt. He instead sees the ghost of Banquo and he cries out and denies affiliation with the murder. This internal struggle after these murders slowly drives Macbeth insane and causes him even more problems in the real world.
