What has Banquo been thinking/dreaming about? [2.1.4-21] How does his attitude to the witches compare to Macbeth's?
This scene finds Banquo in the dark, in conversation with his son, Fleance. Dark is an important symbol in Macbeth, representative of the unknown and of a time of day in which evil deeds may be performed secretly. There are not even any stars; Heaven's "candles are all out."
Banquo tells Fleance that he does not wish to sleep, even though "a heavy summons lies like lead upon me." He begs for Heaven to "restrain in me the cursed thoughts that nature gives way to in repose." Here, Banquo means that he is afraid to sleep because, when he does, he has "cursed thoughts." Later in the scene, Banquo says, "I dreamt last night of the three weird sisters," to which Macbeth replies, "I think not of them." However, we know that this is untrue: Banquo's behavior at the beginning of the scene stands in contrast to what follows after his exeunt, when Macbeth's famous "dagger" speech precedes his exit to murder Duncan, working directly from what the witches have told him:
Hear it not, Duncan; for it is a knell
That summons thee to heaven or to hell.
Banquo is attempting to avoid thoughts of the witches and what they have promised. In the previous act, he cautions Macbeth against believing everything that he has been told by these dark powers, even though some of what was in their prophecy may have come true—that is, that Macbeth has become Thane of Cawdor:
The instruments of darkness tell us truths,
Win us with honest trifles, to betray's
In deepest consequence.
Banquo is very distrustful of the witches and is, as this scene shows, correct in feeling that to dwell upon what they have said may have disastrous results.
In this scene we are told that Banquo has had his sleep troubled with dreams of the witches or the "weird sisters". It is clear that these dreams have not helped him to have a good night's sleep - he says:
A heavey summons lies like lead on me,
And yet I would not sleep. Merciful powers,
Restrain in me the cursed thoughts that nature
Gives way to in repose!
The key difference in the response to how Banquo and how Macbeth relate to the witches and the prophecies lies in the fact that, although both have ambitious thoughts, Banquo chooses not to act on that ambition. Macbeth therefore is the opposite - he chooses to give in to those ambitious thoughts which lead him inevitably to murder and treachery. We can see therefore that in some ways in this play Banquo acts as a comparison to Macbeth - and a rebuke to Macbeth and the path he has chosen to take. It is therefore fitting that it is Banquo's ghost that haunts Macbeth, and of course, one of the key ways in which he haunts Macbeth is by referring to the different ways they both responded to the predictions of the witches.