Thou hast it now: King, Cawdor, Glamis, all,
As the weird women promised; and, I fear,
Thou play’dst most foully for ‘t. Yet it was said
It should not stand in thy posterity,
But that myself should be the root and father
Of many kings. If there come truth from them –
As upon thee, Macbeth, their speeches shine –
Why, by the verities on thee made good,
May they not be my oracles as well,
And set me up in hope? But hush, no more.

– William Shakespeare

Macbeth, Act 3, Scene 1. In this soliloquy Banquo realizes that all the prophecies of the Witches about Macbeth have come true, he is now King of Scotland. However, Banquo is suspicious that Macbeth got the crown by foul means, in other words he was involved in the murder of the rightful King Duncan. But Banquo finds hope and comfort in the rest of the Witches’ prophecy: that he will be the father of many kings. Like Macbeth, Banquo has his own ambitions, but is not willing to sell his soul to achieve them, as Macbeth has done. Losing all trust in Macbeth, Banquo is now socially and morally isolated from his former best friend.