Foakes, R. A. "Images of death: ambition in Macbeth."
Focus on Macbeth. Ed. John Russell Brown. London: Routledge, 1982. 7-29.

Thesis: For Foakes, to say that Macbeth is ambitious is too simplistic: "Macbeth is a play that escapes from ordinary moral boundaries and judgments; it is less about a criminal who must be morally condemned than about a great warrior who breaks through the fear-barrier only to find on the other side not the release and fulfillment he looks for, but a desert of spiritual desolation" (26-7).

Foakes points out that Macbeth uses the word "ambition" only once, and that is when he is seriously thinking about giving up the project of killing Duncan. Although Macbeth says hardly anything about his ambition, he spends a great deal of time making up his mind to kill -- first King Duncan, then Banquo, then Macduff's wife and children. Foakes, exploring the significance of Macbeth's hallucination of the dagger, comments: "A warrior, accustomed to killing on the battlefield, Macbeth, to be fully a 'man' in this limited sense, is driven to face the challenge of killings of a different kind, and his inner drive, embodied in the air-drawn daggers that marshals him towards Duncan, overcomes for him his revulsion at the deed" (26).

Foakes' exploration of this kind of ambition in Macbeth is extremely persuasive. On the other hand, it's not so easy to accept Foakes' assertion that Macbeth retains our sympathy (and even admiration) to the bloody end.

Bottom Line: Worthwhile.