Reading about cell biology and the history of cell theory has been an interesting topic.  What interests me is the understanding the ancients had without understanding cells and the cell theory.  Perhaps when they spoke of possession, they were really talking about bacterial or viral infections in the body.  Perhaps that is a form of spirit possession.  Perhaps that was the way the ancients described entity possessions. After all, even the bugs have their own consciousness/spirit, right?  Weaving and finding a bridge between ancient and modern science is beneficial now because that is the language we speak.  Who knows.