Who is the antagonist in "Macbeth"?

Although opinions differ in the analysis of character roles in William Shakespeare's tragedy "Macbeth," one primary view states that Macduff is a heroic antagonist because he is opposed to the tragic protagonist Macbeth. However, a case can be made that Macbeth is both a protagonist and an antagonist.

The view that Macbeth is his own antagonist rests on the analysis that he is his own worst enemy and undoes himself. Macduff is more commonly considered the antagonist because he stands in moral opposition to Macbeth. Macduff is a man of integrity who ultimately confronts and slays Macbeth. His role as a heroic antagonist is supported by frequent mentions of him being holy.