Conclusion

"Macbeth is a complex study of evil and its corrupting influence on humanity. Some critics argue that Shakespeare adapted historical accounts of Macbeth to illustrate his larger view of evil's operation in the world. The particular evil that the protagonist commits has wide-spread consequences, causing a series of further evils. As a result, the tragedy is not fully resolved through the fallen hero's death but through the forces of good that ultimately correct all the evil Macbeth has unleashed. The witches, through their ambiguous prophecies, represent a supernatural power that introduces evil into Macbeth. Their equivocations—the intentional stating of half-truths—conceal the sinister nature of their predictions, and Macbeth does not consider the possibility that they are trying to deceive him. In fact, the Weird Sisters' attempts at misinformation succeed not only because they favorably interpret the hero's future but also because their revelations seem to come true almost immediately. Although inherently malevolent, the witches' prophecies do not necessarily signify the actual existence of evil but suggest instead the potential for evil in the world. The Weird Sisters themselves do not have the power to enact a diabolic course of events such as that which ensues in Macbeth; rather, their power lies in tempting humans like Macbeth to sin. When Macbeth succumbs to the temptation to commit murder, he himself is the active catalyst that unleashes evil upon the world. The evil, which initially manifests itself in Duncan's murder, not only disintegrates Macbeth's personal world but also expands until it corrupts all levels of creation, contaminating the family, the state, and the physical universe." - enotes.com

"Macbeth is a tragic hero because he has the potential for greatness, but it is undercut by his greed and lust for power. The prophecies of the Witches provide the spark by which Macbeth’s soul is set on fire. Once he is presented with the chance to further his own ambition, he lets nothing and no one get in his way. Loyalty becomes treachery and friends become enemies. Even Lady Macbeth’s death is naught but a nuisance. Macbeth tells Seyton that she should have waited until tomorrow to die because then he could have spent time mourning for her.

In the end, the play has come full circle. At the beginning, Macbeth defends the King against those who would overthrow the crown. In the end Macbeth, who has taken the crown by blood and deceit, is overthrown and rightful rule is restored." - enotes