Neither person is really present.

The first appearance in popular language is a "wraith"; the second is a "ghost" in ordinary speech.

Both are hallucinations.
So far Mr.Galton would go, but mark what follows! Everybody allows the existence of dreams, but comparatively few believe in dream stories of _veracious_ dreams.

So every scientific man believes in hallucinations, {68} but few believe in _veracious_ hallucinations.

A veracious hallucination is, for our purpose, one which communicates (as veracious dreams do) information not otherwise known, or, at least, not known to the knower to be known.