Good ol' King Saul, on top of his many transgressions, once convinced a necromancer to summon the dead prophet Samuel for a consultation beyond the grave.
It's interesting to me that the biblical record actually says that Samuel showed up from the beyond (and chewed out King Saul - but that's another story). Yet, in Sunday School-level teaching, they told us that any communication with the dead is actually communication with demons in disguise.
But that's another story. I'm not interested in communicating with the dead. I'm interested in the phenomenon of people who present as dogmatic truth, what is at best an educated guess.
The first step to acquiring knowledge (the precursor to understanding and wisdom, hopefully), is to admit ignorance. Because saying, "I don't know", when I don't know, is a proclamation of truth.