Humanity’s interpretation of the appearance of what we call “ghosts” has largely remained constant throughout history.
In general terms, when the apparent apparition of a person who is, for lack of a better term, “temporally misplaced” occurs (i.e. the apparition appears to be a deceased individual), we presume that what we’ve seen is a spirit, likely stemming from some energetic presence that emanates from the disembodied soul of of a once-living person. Thus, our study of such temporal apparitions has remained what we call “supernatural,” and attempts at communicating with ghosts most often fall under the categorization of conversation with “the spirit world” or “the other side.”
It actually seems more of a possibility than ghosts being 'spirits'.
But all the time in the back of these things there was the hill-quiet and the stony pastures, and sometimes they made me ashamed of what I was - human and full of a thousand wormy thoughts and selfishness, but more often they were like hands to heal. from 'Now In November' by Josephine Johnson
This is interesting. I did cheat a bit and found myself skimming the page as I was getting a little lost in this one .
The theory put forward would explain why ghost buses and ships are sometimes seen though, and that's something I've thought about when reading 'ghost stories'. Also the times when people see a ghost of someone who is still alive etc. And why some are dressed in their natty Sunday best, whilst others are dagging around in nightgowns and bare feet. Good stuff to mull over, thanks S.W.