Those of us who believe evil spirits exist tend to think of them as putting thoughts in our heads, but suppose that they also often stir up passions within our hearts? Maybe instead of thinking of them as wandering disembodied intelligences that also have will and desire we should instead think of them as wandering disembodied passions that also have will and intelligence. Maybe along with thinking “I wonder if that thought is from a demon” we should sometimes think “I wonder if that sudden rush of emotion is from a demon”. This view seems to fit the Biblical references to evil spirits about as well as the traditional one. (See 1 Sam 16:14-15,23; 19:9-10 for example.)