Is it a contradiction of Catholic philosophy to believe in ghosts, such as poltergeists and things that go bump in the attic, so to speak? And if so, is there Catholic theory behind such phenomena?
I'm going to copy/paste most of the answer here and make a few comments, but for the most part, it stands on it's own. The reason I'm including the whole text is I'm afraid the present-day CAF folks might find out this post still exists with one of their apologists recommending an author who is so famously charismatic ("new age") and delete the whole thing.
I completely agree with this, which might surprise a few people. But before you think my evil twin is posting, read on...
First, the Church forbids us to conjure up the dead (Catechism 2116-2117). Peter Kreeft in his book Everything You Ever Wanted To Know About Heaven (pgs 34-35) says the reason for “this stricture is probably protection against the danger of deception by evil spirits. We are out of our depth, our knowledge, and our control once we open the doors to the supernatural. The only openings that are safe for us are the ones God has approved: revelation, prayer, His own miracles, sacraments, and primarily Christ Himself…The danger is not physical but spiritual, and spiritual danger always centers on deception.”
“Nevertheless, without our action or invitation, the dead often do appear to the living. There is enormous evidence of “ghosts” in all cultures. What are we to make of them?” He goes on to say “We can distinguish three kinds of ghosts, I believe. First, the most familiar kind: the sad ones, the wispy ones. They seem to be working out some unfinished earthly business, or suffering some purgatorial purification until released from their earthly business. These ghosts would seem to be the ones who just barely made it to Purgatory, who feel little or no joy yet and who need to learn many painful lessons about their past lives on earth.Now here is the biggest Catholic site not the Vatican not only affirming through this Kreeft quote (check his work out if you are unfamiliar) that the average Catholic person can have communication from those who have passed, but also attempting to define the state of being of those on the other side.
Second, there are malicious and deceptive spirits—and since they are deceptive, they hardly ever appear malicious. These are probably the ones who respond to conjurings at seances. They probably come from Hell. Even the chance of that happening should be sufficient to terrify away all temptations to necromancy."I completely agree with this, also. John Edward, when he started out, called what he did a "seance." He stopped doing that, thankfully, because a seance, the way I use the word, does mean attempting by some human "power" to "conjure" the dead. Ouija boards spring to mind or rituals designed for this purpose.
DON'T DO THAT. Ever. As John himself said, "You wouldn't just invite a random stranger into your house, would you?" Some might say, "But if it works...." It doesn't. Srsly and factually, even if something happens, you are not the one doing it. No one has any power like this. The Lie the Liar affirms to you is that you do. On to more positive things...
"Third, there are bright, happy spirits of dead friends and family, especially spouses, who appear unbidden, at God's will, not ours, with messages of hope and love. They seem to come from Heaven. Unlike the purgatorial ghosts who come back primarily for their own sakes, these bright spirits come back for the sake of us the living, to tell us all is well. They are aped by evil spirits who say the same, who speak 'peace, peace, when there is no peace'. But the deception works only one way: the fake can deceive by appearing genuine, but the genuine never deceives by appearing fake. Heavenly spirits always convince us that they are genuinely good.Here we disagree somewhat. While the characterization of how they appear is okay, "at God's will not ours," the personality and their location is not what I would say. Purgatory is not a place. Not a single steady state that begins and ends for us, like a room we enter and leave. It's a continuum. More like riding an escalator. From barely escaping the gates of Hell to entering the perfection of Heaven, we will be at whatever level "matches" our soul when we pass and evolve more and more toward God as our souls are healed and perfected. And all of them aren't that bright and happy-seeming when they come through. While they bring light and knowledge, they are quite individual, probably as identifying characteristics.
People who have gotten messages through mediums are often surprised that it's the atheist in the family they've heard from or some really mean guy. But as I've said before, true contact with those who have passed brings enormous spiritual benefit. Perhaps the "wispy" spirits are just closer to hell. I'm no expert in all of this, but I do know there is a "heaven" of which we have yet to speak, and while the very upper reaches of Purgatory are wonderful beyond our imaginings, they are not this Heaven. But Paul said there were three, so perhaps he mistook higher reaches of Purgatory for Heaven. Or, there is just something beyond Heaven. That's coming up in some other post.
Everything You Ever Wanted to Know about Heaven By Peter Kreeft
Ghosts and Poltergeists By Herbert Thurston, SJ
Seven Kinds of Ghosts Seven Kinds of Ghosts (article)By Bro. John-Paul Ignatius
Most high, glorious God, enlighten the darkness of my heart and give me Lord, a correct faith, a certain hope, a perfect charity, sense and knowledge, so that I may carry out Your holy and true command AMEN (Saint Francis' prayer at the Crucifix of San Damiano)