By the time Malcolm and Macduff meet in act 4, scene 3, the political situation in Scotland has deteriorated into near chaos and Macduff is ready to exact vengeance. Macbeth, after hearing the witches’ prophecies, has vowed to kill Macduff so that he will not be killed by him, but then he learns that Macduff has fled to England. He prepares to attack Macduff’s castle in his absence. Upon hearing that her husband has left the country, Lady Macduff is both furious and terrified, because she knows that she and her children are defenseless; the murderers soon arrive, kill her son, and chase her out.
In scene 4, Macduff and Malcolm have returned to Scotland with their armies. They do not yet know that Macduff’s family is dead. Resolute on pressing through their sorrow, they wonder how things got so bad as they strategize their plan of attack. Macduff says that heaven itself must empathize with the sorrow (“dolor”) that everyone in their country is feeling. Shakespeare uses the repetition of “new” to emphasize the daily onslaught of ills:
Each new morn
New widows howl, new orphans cry, new sorrows
Strike heaven on the face, that it resounds
As if it felt with Scotland...
The men discuss the best approach to take. They worry that by acting against Macbeth, they will be making the situation worse. Macduff is urging Malcolm to take command, but he worries that he would be an even worse ruler than Macbeth. He does not trust himself not to succumb to the evils that a lust for power creates in men. Neither of them wants to open himself up to the foul desires that have turned Macbeth from an apparently good person into a tyrant.
Even angels have been tempted and destroyed by reaching above their station, Malcolm notes, alluding to Satan’s fall: “Angels are bright still, though the brightest fell.” It is not always easy to tell who is in the right, as “foul” things may seem lovely or “wear the brows of grace...”
Malcolm agrees that things are not always what they seem and that goodness is not enough to keep the country safe from tyrants. He addresses Scotland directly (the literary device of apostrophe):
Bleed, bleed, poor country!
Great tyranny, lay thou thy basis sure,
For goodness dare not check thee.
Malcolm also worries that in unseating Macbeth, who is now king, he would be no better than him, because he would also be a traitor. Macduff takes a similar view, noting that the situation is getting worse every day and that there is no easy solution. If he were to remove Macbeth, it would engender further evil, or “more vices.”
When I shall tread upon the tyrant's head,
Or wear it on my sword, yet my poor country
Shall have more vices than it had before...
Malcolm extends this line of thought, saying that he has so many vices within him that in comparison, “black Macbeth / Will seem as pure as snow...”
They continue to agree that the illegitimate desire for power is a deeply harmful quality but that they are left with no choice. Malcolm says that the arguments they are now considering for taking down Macbeth are the same ones he had used to get Malcolm to join against Duncan. Macduff finally wears him down, and he agrees to move ahead.
What I am truly,
Is thine and my poor country's to command...