Doctor von Niemann
Ah, this is it. Traité sur les apparitions des esprits et sur les vampires, by Augustin Dom Calmet, in 1746. "Let us suppose that these corpses do not actually stir from their tombs, but only the ghosts or spirits appear to the living. Wherefore do these phantoms present themselves and what is it that energizes them? Is it actually the soul of the dead man which has not yet departed to its final destination?"
