Is Banquo less ambitious than Macbeth?
Yes. There is no evidence that Banquo is especially ambitious. There is a signifcant passage in Act 2, Scene 1, lines 25-41, in which Macbeth is cautiously and subtly sounding Banquo out as to whether he might be willing to become involved in Macbeth's plot againist Duncan. Macbeth says, "If you shall cleave to my consent, when 'tis, / It shall make honor for you," and Banquo replies, "So I lose none / In seeking to augment it, but still keep / My bosom franchised and allegiance clear, / I shall be counseled." This reply shows that Banquo is a loyal subject of the king and has no great ambition to advance himself except through promotion earned by his own merits. He seems satisfied with his present position. He is not envious of Macbeth, who in a very short time was promoted to being Thane of Glamis and Thane of Cawdor. There is a definite contrast between Macbeth and Banquo from the beginning. Macbeth feels inferior to Banquo. Macbeth says to himself: "There is none but he / Whose being I do fear; and under him / My genius is rebuked, as it is said / Mark Antony's was by Caesar" (3.1.58-62). The reference to Caesar is not to Julius Caesar but to Octavius Caesar.