MACBETH:
Speak if you can. What are you?
FIRST WITCH:
All hail, Macbeth! Hail to thee, Thane of Glamis!
SECOND WITCH
All hail, Macbeth! Hail to thee, Thane of Cawdor!
THIRD WITCH
All hail, Macbeth, that shalt be king hereafter!
BANQUO
Good sir, why do you start and seem to fear things that do sound so fair? I’ th’ name of truth, are you fantastical, or that indeed which outwardly you show? My noble partner you greet with present grace and great prediction of noble having and of royal hope, that he seems rapt withal.

MACBETH
Stay, you imperfect speakers. Tell me more. A prosperous gentleman, and to be king stands not within the prospect of belief.
Witches vanish.
BANQUO
The earth hath bubbles, as the water has, and these are of them. Whither are they vanished?
MACBETH
Into the air, and what seemed corporal melted, as breath into the wind. Would they had stayed!
BANQUO
Were such things here as we do speak about? Or have we eaten on the insane root that takes the reason prisoner?
MACBETH
Your children shall be kings.
BANQUO
You shall be king.

It is the part of ourselves we do not normally admit to consciousness, let alone expression in action, that slips past the inner censor into our dreams and fantasies.

OUR REBEL EMOTIONS by Bernard Mobbs (1970)

This devilishly charming fellow is only a human nature characteristic. He is human nature itself; the corporeal personality honoring, respecting, reverencing, adoring and worshipping itself as king and as god in his own world.

THE WORD – A PHILOSOPHY (1958) by Edna Sarah Beardsley (re: devil)