P is for Possibillian
Yes, "possibillian" is really a word. Granted, you won't find it in any dictionary (yet), but there's an entry for it on wikipedia, so it must be a real word, right?
Possibillian was coined by neuroscientist David Eagleman in response to being asked whether he was an atheist or a religious person. He replied "I call myself a Possibilian: I'm open to ideas that we don't have any way of testing right now. "
"Doubt is not a pleasant condition, but certainty is absurd"
Once we get beyond the toolbox of science, no one knows anything for certain. Actually, the only thing we do know for certain is the magnitude of things we don't know. Being a possibillian means you don't have to limit yourself to one belief system - you can be open to multiple possibilities and ideas at the same time. And it's okay to say "I don't know" - what a novel and freeing idea!