Fear

Siegfried and the Green Lanterns are fearless but how do they survive? Fear is a survival mechanism. Courage is not fearlessness but the ability to do what we are afraid to do.

Conan, at least in Poul Anderson's Conan The Rebel (New York, 1981), fears supernatural threats but overcomes this fear:

"Yes, Conan thought, if he must fight through graveyard horrors to regain Belit, he would." (p. 102)

In a sword and sorcery novel, "...graveyard horrors..." are real, not just imagined. Earlier in the novel, it was suggested that a civilised, literate person has less reason to fear the supernatural but surely not in a world where greater knowledge does not disprove but confirms the existence of gods, ghosts and demons - unless, of course, the mere growth of secular knowledge does weaken the influence of the supernatural entities, as is suggested in a few other works of fiction, including some by Anderson?