Kahn, Coppélia. "The Milking Babe and the Bloody Man in Coriolanus and Macbeth."
Man's Estate: Masculine Identity in Shakespeare. Berkeley: U of California P, 1981. 151-192.

Thesis: In the "Introduction" to her book Kahn states her general approach: "In this book, my intention is to use psychoanalytic theory to understand Shakespeare's conception of identity." She continues, "I am not trying to psychoanalyze individual characters, but to discover dilemmas of masculine selfhood revealed in the design of the works as a whole" (2).

As for Macbeth, Kahn says that his fundamental problem is that "though he excels as a virile warrior, Macbeth has not fully separated himself from the feminine source of his identity" (172). The background for this statement is the psychoanalytic theory which states that it is particularly difficult for a male child to develop his own masculine identity because in order to do so he must come to terms with the identification that every infant -- male or female -- makes with his mother. In Macbeth, according to Kahn, this developmental process is incomplete, so that he exhibits an exaggerated, violent "manliness" while at the same time remaining extremely susceptible to feminine influence. Kahn explains how this susceptibility is represented in the play:

The sources of his sexual confusion are the witches, who direct their mischief toward him, and Lady Macbeth, who seeks vicarious fulfillment through him. These female beings ally themselves with destruction, not creation (Lady Macduff, appearing in only one scene as an anxious and defenseless mother, is a foil to them). Macbeth's susceptibility to them, and his inability to maintain and defend his conceptions of manliness, emanate from his unconscious dependency on them as mentors.   (173)

Evaluation: All of this may sound more difficult than it actually is. Most of Kahn's comments on Macbeth can be understood by those of us who don't have a deep understanding of psychoanalytic theory. For example, she has an eloquent description of Macbeth's state of mind in the last part of the play:

After the murder of Macduff's family, [Macbeth] fluctuates between two states, both designed to quell his real feelings. On the one hand, he is desperately brave and confident, laughing all to scorn; on the other he is dead to feeling--weary with tedium vitae, empty of joy or sorrow. He who wanted to do "all that may become a man" has accomplished nothing.   (192)

Bottom Line: Generally insightful, despite the psychoanalytic baggage.