Scully and Mulder in “How the Ghosts Stole Christmas”

Scully

These are tricks that the mind plays. They are ingrained cliches from a thousand different horror films. When we hear a sound, we get a chill. We-we see a shadow and we allow ourselves to imagine something that an otherwise rational person would discount out of hand. The whole... the whole idea of a benevolent entity fits perfectly with what I'm saying. That a spirit would materialize or return for no other purpose than to show itself is silly and ridiculous. I mean, what it really shows is how silly and ridiculous we have become in believing such things. I mean, that... that we can ignore all natural laws about the corporeal body... that-that we witness these spirits clad in-in their own shabby outfits with the same old haircuts and hairstyles never aging, never... never in search of more comfortable surroundings-- it actually ends up saying more about the living than it does about the dead.

Mulder

Mm-hmm.

Scully

I mean, Mulder, it doesn't take an advanced degree in psychology to understand the... the unconscious yearnings that these imaginings satisfy. You know, the-the longing for immortality the hope that there is something beyond this mortal coil... that-that we might never be long without our loved ones. I mean, these are powerful, powerful desires. I mean, they're the very essence of what make us human. The very essence of Christmas, actually.

Mulder

Tell me you're not afraid.

Scully

All right. I'm afraid... but it's an irrational fear.