It is notable that Campbell is a non-believer, beyond atheist, as he says in the same interview. Campbell is a believer in teachers, writers, authors, poets, songwriters, etc. He does not believe in supernatural.
Campbell: "The umbilical point, the humanity, the thing that makes you human and not supernatural and immortal—that’s what’s lovable." ... "The idea of the supernatural as being something over and above the natural is a killing idea. In the Middle Ages this was the idea that finally turned that world into something like a wasteland, a land where people were living inauthentic lives, never doing a thing they truly wanted to because the supernatural laws required them to live as directed by their clergy. In a wasteland, people are fulfilling purposes that are not properly theirs but have been put upon them as inescapable laws. This is a killer. The twelfth-century troubadour poetry of courtly love was a protest against this supernaturally justified violation of life’s joy in truth. So too the Tristan legend"
As for Marshall McLuhan, in perhaps his most famous work from 1967:
“Joyce is, in the Wake, making his own Altamira cave drawings of the entire history of the human mind, in terms of its basic gestures and postures during all the phases of human culture and technology. As his title indicates, he saw that the wake of human progress can disappear again into the night of sacral or auditory man. The Finn cycle of tribal institutions can return in the electric age, but if again, then let’s make it a wake or awake or both. Joyce could see no advantage in our remaining locked up in each cultural cycle as in a trance or dream. He discovered the means of living simultaneously in all cultural modes while quite conscious.” — the book “The Medium is the Massage: An Inventory of Effects” by media analyst Marshall McLuhan and graphic designer Quentin Fiore, and coordinated by Jerome Agel. It was published in March 1967