This question is illuminated in Apuleius and Plutarch and Maximus of Tyre by a discussion of the daemon of Socrates.
"Roman Society from Nero to Marcus Aurelius"
Samuel Dill
He never intended to publish "Queen Mab" as it stands; but a few years after, when printing "Alastor", he extracted a small portion which he entitled "The daemon of the World".
"The Complete Poetical Works of Percy Bysshe Shelley Volume III"
Percy Bysshe Shelley Edited by Thomas Hutchinson, M. A.
Merlin the magician, born of a spirit or daemon, claimed Arthur before birth and became his teacher afterwards.
"The Fairy-Faith in Celtic Countries"
W. Y. Evans Wentz