The word “ghost” comes from geist, the German word for spirit. A poltergeist, or noisy ghost, is a spirit that makes its presence known with acts of mischief—throwing toasters or dining room chairs around. Martin Luther was one of the earliest to use the term “Polter-Geister.” The Modern Catholic Dictionary (Eternal Life) defines “ghost” as “a disembodied spirit.” - See more at:
For Jansen, that moment triggered a long reckoning of the experience he considered supernatural with the teachings of his church. He says that he sees no conflict between what the church teaches and a belief in ghosts. “Belief in all that is visible and invisible is a tenet of our faith, and in the end, spirits are part of our holy tradition,” says Jansen.
Peter Kreeft, a philosophy professor at Boston College, has written, “The dead often do appear to the living. There is enormous evidence of ‘ghosts’ in all cultures.”
Kreeft says that there is “no contradiction” between ghosts and Catholic theology. “Ghosts appear on earth, but do not live on earth any longer,” he says. “They are either in heaven, hell, or purgatory.”
Kreeft recalls the appearance of the dead Samuel to the witch of Endor in 1 Samuel, one of the most famous ghost stories in the Bible. When Samuel appeared, says Kreeft, “he was not on earth, though that’s where he appeared.” Similarly, “the angel of the Lord” that appears frequently in the Old Testament, which some theologians think was the preincarnate Christ, “is not actually on earth, but simply appeared to those that were,” he says.
“Ghosts confirm, rather than refute or disturb, Catholic theology of the afterlife,” says Kreeft. “Especially the very existence of a life after death, which is the main point skeptics dispute.”
Ghost skeptics, of course, are legion, and always have been. The church, too, has marshaled paranormal skeptics to battle against the encroachment of what it has called spiritualism or spiritism. Jesuit Father Philipp Schmidt wrote in the early 1960s that the “cult of spirits” was, for many people “a kind of substitute religion.”
Schmidt writes that attempts to speak to dead relatives were “not in keeping with the wisdom of God.” Human beings can’t control the supernatural—only God can. Spiritualism, he said, is hostile to all the world’s religions, and the miracles attributed to Christ and the saints “stand on a level high above all spiritistic interpretation.”
“Wherever magic begins,” Schmidt writes, “where mirrors and windowpanes break in pieces … where one can ring up on the telephone Napoleon, Cleopatra, Herod, or Paracelsus as though they were acquaintances from the rowing or the tennis club … then spiritualistic nonsense begins.”