The Origin of the Idea of Ghosts

There was a kind of collection of traditions that when you see a ghost, on the whole, it wasn't good news. But they also believe to day, or many people do, that ghosts are in possession of a knowledge of the future. It was understood sometimes that if a ghost appeared an they didn't say anything, people thought they had a communication they wanted to make. And there are one or two spells to try and encourage the ghost to answer questions. The most amazing ones were you had a whole full blown ritual when you procured the skull of probably the person you wanted to interrogate - like your great aunt.