Thesis: Mack doesn't really have a single thesis. His essay is readable and persuasive, but not tightly organized.

The essay has seven sections:

1. On the play as the story of "an heroic and essentially noble human being who, by visible stages, deteriorates into a butcher" (183).
2. On the play as a "medieval story of the rise and fall of a usurper . . . colored by . . . a number of contemporary interests and events" (184), such as the Gunpowder Plot.
3. On the play's theme of "the consuming nature of pride, the rebellion it incites to, the destruction it brings" (187).
4. On the difference in character between Macbeth and Lady Macbeth.
5. On how "Every element it [Macbeth] contains lives with a double life, one physical, one metaphysical" (191). In this section Mack discusses the imagery of night and blood, and also the nature of Macbeth's ambition.
6. A further discussion of the "double life" of the play, focused on the themes of feasting and of children.
7. On the last scenes of the play, emphasizing that "What comes home most sharply to us as we watch these last scenes performed is the twistings and turnings of a ruined but fascinating human being, a human being capable of profound even if disbalanced insights, probing the boundaries of our common nature ever more deeply in frantically changing accesses of arrogance and despair, defiance and cowardice, lethargy and exhilaration, folly and wisdom" (195).