It is helpful to think of this scene as a job interview. Malcolm begins by suggesting that Macduff may be prepared to betray him as "a sacrifice" to his previous leader, Macbeth. Macduff passes this stage of the interview by boldly announcing, "I am not treacherous." Still, Malcolm persists: Men may look as bright as angels on the outside but still harbor secret feelings within. Why, he asks, did Macduff desert his wife and children? At this point, Macduff nearly fails the test: He cannot believe that Malcolm is so short-sighted not to realize that his interests lie in defending not only his family but the whole nation of Scotland.
As in Ross' speech in Act IV, Scene 2, the context of this entire scene has been set in terms of the country as a whole: Macduff explains to Malcolm that "Each new morn . . . new sorrows / Strike heaven on the face, that it resounds / As if it felt with Scotland"(4-7). Later, Macduff cries out "O Scotland, Scotland . . . O nation miserable!" Macbeth's motivation in murdering Duncan may have been personal, but its effects have become very much public.
Malcolm's next move is a daring piece of reverse psychology: He claims that as a future king, he himself will be even more malicious and barbarous than Macbeth. To understand this scene, the audience must be aware from the start that Malcolm is lying when he suggests that he possesses no virtues, no nobility, no honor, and no qualities of kingship.
Macduff's response to this suggestion is at first cautious. His speech beginning with the words "Boundless intemperance in nature is a tyranny . . . " has a diplomatic tone. Macduff argues, probably against his better judgment,