Macbeth was Sane
Although Macbeth may have suffered from post-traumatic stress disorder, his suffering does not constitute insanity. Macbeth was in a healthy mindset when he embarked on his murderous spree and treacherous rule of Scotland. His actions and reactions prior to and throughout his tenure as King of Scotland were normal considering the circumstances. The following evidence will prove that Macbeth was indeed sane.
The first thing I would like to point out is Macbeth's clear understanding of his motives and their consequences. After he heard the prophecies of the weird sisters, his ambition got the best of him. He immediately considered murdering Duncan and the morality of the murder. Macbeth knew his thoughts were wrong and said to the stars, "hide your fears, let not see my black and deep desires (I.4.50-51)." This acknowledgment of the sinfulness of his desires shows that Macbeth's mind was functioning properly. Macbeth also acknowledges that there would be consequences if he murdered Duncan. He thought to himself, " if the assassination could trammel up the consequence, and catch with his surcease, success (I.7.2-4)," the decision to murder Duncan would be easier. These examples prove that Macbeth was not impulsive with his thoughts. Instead, like anyone else, he realized the gravity of his desires. If Macbeth was insane, he would not have thought twice about the murder and its consequences.
Macbeth also demonstrates guilty feelings when he considers murdering Duncan. These guilty feelings came about when he analyzed the relationship between himself and Duncan. Not only was he Duncan's subject and soldier, he was Duncan's host. He realized that entertaining thoughts of murder while Duncan was a guest at Inverness was completely wrong. Duncan was there, "in double trust (I.7.12)," and to violate that trust would be a corrupt action. It is obvious that Macbeth was thinking clearly because he understood the significance of his thoughts and felt guilt over them. This guilt would not be present in a crazy man because a crazy man kills without remorse.
Another important matter to discuss in determining Macbeth's mental state is Macbeth's hallucinations. In my professional opinion, these hallucinations were not the result of insanity. I feel that they were manifestations of the stress Macbeth was feeling. In no way do they suggest that Macbeth was insane. Rather, they prove that Macbeth was reacting the way any other person would to extremely stressful and gruesome situations.
Macbeth's first hallucination of the bloody dagger leading him to Duncan's room was a way for Macbeth's mind to release some of its anxieties concerning the act of murder. Although Macbeth had killed before, he had never killed for the purpose of improving his position. His previous killings were in battle where he was killing his enemy, not a man...