In plays asides are statements delivered by an actor to the audience in such a way that it appears that the other actors are unaware of what is being said. Thus, an aside is an important device for plays as they are employed by playwrights to reveal the private thoughts, reactions, and motivations of the character who is speaking. In addition, asides are used to indicate private conversations between characters that others cannot hear.
In Act III, Macbeth decides that Banquo poses a threat to his retaining the crown as the witches have predicted; consequently, he decides to hire murderers who already have a grudge against Banquo to kill him. When they report that Banquo has been slain, but his son Fleance has escaped, Macbeth recalls the words of the witches that Banquo's sons would be kings and his fears are revived.
- In his first aside of this act, he reveals his growing paranoia, which comes directly after the murderers' report:
Then comes my fit again...
But now I am cabined, cribbed, confined, bound in
To saucy doubts and fears.—But Banquo’s safe? (3.4.22-26)
Shortly after these private words of Macbeth, the ghost of Banquo appears. This appearance is typical of many of Shakespeare's plays, as ghosts often return to the villains when they are troubled.
After he joins his guests at the banquet table, Macbeth sees Banquo's ghost in his seat and, becomes terrified by it. Worried about what the guests will surmise, Lady Macbeth attempts to diffuse the situation by telling the guests that Macbeth is merely suffering from a recurrence of a childhood condition which amounts to nothing. She urges them to ignore Macbeth, but whispers to Macbeth to shake him from his fears that draw attention from the noblemen:
If much you note him,You shall offend him and extend his passion.Feed and regard him not. (aside to MACBETH) Are you a man? (3.4.59-61)
O proper stuff!This is the very painting of your fear.This is the air-drawn dagger which you saidLed you to Duncan....(3.4.63-66)
So, in another aside Lady Macbeth speaks,
Fie, for shame! [= "Nonsense!" Lady Macbeth tries to embarrass him to act bravely.] (3.4.86,88)
But, when Macbeth continues to insist that Banquo is before him, Lady Macbeth then scolds him aloud for having disturbed the "mirth" of the gathering. After a concerned Ross asks him what he has seen, Lady Macbeth becomes worried about what the noblemen will think, so she asks the guests to leave because her whispered asides to Macbeth have been ineffective in bringing him out of his optical illusions.