The movie Exorcist was loosely based on a novel Thomas B. Allen,
describing a famous exorcism performed in St. Louis in 1949. There
were numerous witnesses to the horrifying events which occurred in the
multiple procedures involved.
   The question inevitably arises: Are demonic possessions real or
only symptoms of psychic disorder? The expected reply from the
scientific community is complete rejection of the concept of demons.
One analysis of the St. Louis case stated that the phenomena of
shaking beds, heavy furniture sliding unassisted across the floor,
objects flying about the room, strange noises, voices and odors,
writing appearing on the skin of the victim, and much else, are
effects that ?any determined teenage prankster could easily produce.?
Really? That author must know dozens of highly creative teenagers. He
claims the victim could produce writing on his skin by scratching with
his fingernails, and dismisses all mysterious events as hearsay or
from unreliable witnesses.
  Well, what could be easier than demolishing an argument by calling
it a pack of lies? So, my question is: Is there any objective,
irrefutable support for the reality of demonic possession?

I hope nobody wastes your time by citing the Bible.

nelson-ga: Agreed. I am asking for objective, irrefutable evidence.

I sincerely doubt that such evidence exists. Most scientists of my
acquaintance do not believe in so-called paranormal phenomena
(telekinesis, clairvoyance, and such); there is an absence of
well-documented proof. Anyone who can present irrefutable scientific
proof of psychic or spiritual occurrences can claim James Randi's
million dollar prize. So far, Randi's money is safe.

While I believe that spiritual entities exist, I do not try to justify
my beliefs by scientific means. Proving the immaterial by using
material means is like trying to nail Jell-O to the wall.

Pink: I agree in general terms with your comment. But demonic
possession seems to me an unique paranormal phenomenon. As someone
commented, are the scores of witnesses in the 1949 case all liars?
What is lacking in that case for some reason is photographic evidence,
which weakens the position of those involved. One of the priests
involved in the case recently died, maintaining what he saw was true.
   Having been a laboratory researcher for thirty years, I have seen
so much bullshit from so-called scientists that I am thoroughly
skeptical of all claims, scientific and otherwise. I am agnostic, but
believe the scientific community simply blows away any contrary
opinions as untenable and unworthy of further discussion. To me, this
is arrogance. I am rather certain there are some phenomena that are
unexplainable by science, but the scientists evade the issue by saying
they are non-existent rather than saying: Perhaps we don't know
EVERYTHING.

But if someone had "irrefutable proof" that demon possession is real,
why would it be kept secret? Why not collect the million from Randi,
make a documentary or two for TV, publicize the hell out of it (so to
speak)? Doesn't the very fact that you are asking researchers to seek
such evidence imply that it's difficult to find? If it existed, why
would it be difficult to find?

Dunno if what I'm saying makes any sense. I may be starting to ramble.
And I can't even use the "devil made me do it" excuse.

To reiterate: I believe that spiritual entities exist. What I do not
believe is that they can be scientifically proven to exist. Heck,
nobody has even proven that there is such a thing as a soul.

Pink: You are right of course. If irrefutable proof existed of demonic
possession, it would be publicized. Perhaps I worded my question
inaccurately.
(I know universally acceptable proof does not YET exist. That would
undermine our huge superstructure of Science. My $10 is safe.) If
demonic possession is real, each incidence would be unique. Science
requires a control and reproducile data. How do you repeat an unique
event? How do you run a control?
If an eminent scientist observed an exorcism and was convinced of the
reality of a demon, he would be drummed out of the society of
scientists.
  I guess that what bothers me are the many unexplainable phenomena
reported are all dismissed out of hand. Even if 99.5% are fraud, what
about the rest?
Is EVERYBODY who makes these claims a liar?

Well, the fact that at least exocisms seem to work would indicate that
it's not about a psychic disorder.

Kriswrite

I think the closest you will come to proof is this book which
chronicles 5 cases of average Americans

Hostage to the Devil: The Possession and Exorcism of Five Contemporary Americans
http://www.amazon.com/exec/obidos/ASIN/006065337X//104-0733334-4822328
Read the reviews.  Some of the comments make my skin crawl.  I bet
it's a fascinating read. Be sure to check out the "Other Book" read
and purchased sections.

~~Cynthia

cynthia-ga: Many thanks for the lead. I shall pursue. Exorcism is
fascinating because it seems to reveal the existence of pure evil and
challenges scientific and medical orthodoxy.
monroe22

kriswrite: An astute comment...thanks,
monroe22

Isn't exorcism only a practice of the Roman Catholic church?
Are there records of persons of an other or no belief becoming possessed?
Doesn't a possessed person have to have a prior strong acceptance that
there really could be an evil spirit that could possess him, imbedded
(like wicked journalists among the troops, sorry) imbedded in his
religious concepts?
If/when exorcism works, then - contrary to what kriswrite comments - 
I think "possession" could very well a psychic disorder that is
"cured" by the religious practice/ritual of exorcism, which also fits
in with the person's religious concepts.  If one believes in evil
forces, one believes just as strongly in good forces and their power
to overcome the evil.

The fact that exorcisms seem to work does not prove that demon
possession rather than mental disorder was the cause. I would expect
that an exorcism would have a powerful placebo effect.

Incidentally, Catholics are not the only ones performing exorcisms.
Some Pentecostal sects are very keen on this, too. I've heard of
Buddhist ceremonies for driving demons out, but I am not well-versed
in Buddhism, so I'll leave comment on that to others.

Thanks for the additional info.  Yeah, I was thinking of Buddhists
too.  Certainly  in the Buddhist temple art in Tibet one could get the
impression that there are terrible things that can happen to people
that aren't working on their Karma.
And the masked dances are rituals of driving away demons.
And the Pentecostals also have strict religious concepts that would
allow for evil spirits.

Exorcism is also practiced in Judaism and Orthodox Christian rites.

Pink: Must respectfully disagree with you that successful exorcism can
be attributed to placebo effect or suggestion. Those cases that call
for exorcism would be classified by modern medicine as pathologically
or criminally insane, and INCURABLE by psychiatry or other medical
procedures. Those types are sedated and restrained. Now, if suggestion
could cure them, why aren't there brilliant psychiatrists or others
who could cure these desperate cases by suggestion? Furthermore, the
extreme cases cannot be communicated with in order to make the
suggestive cure...they are too violent and physical. The exorcist does
not communicate with the patient, but with the demon.

Hi Monroe22,
It seems like you are better informed on this subject than we are, and
Pink's first comments are the ones that are really directed at your
question (last lines).
I agree with her, applying my lesser powers of logic and taking the
(unread) reports with a grain of salt.  Do you want to believe that
there could be demonic possession?
Thanks for your last comments.  I wonder when the last Jewish and
Orthodox exorcisms were performed?
Yes, persons who are exorcised (successful or not) definitely fall in
the medical categories you mention and could be incurable in the hands
of even brilliant psychiatrists.  They can't always "cure" people with
lesser problems, as demonstrated by patients' chasing around from one
to another, people who mange to live halfway normal lives.  Is there
any record of psychiatrists handling or inspecting cases of demonic
possession?
I wonder if there are any deeply religious psychiatrists.  Seems like
a profession  - like that of philosopher -  that would have a very
sceptical attitude towards acceptance of a higher being, especially
one that could influence persons, even judge over them on a final day
of reckoning.
If we can assume for a moment that my first comment's rhetorical
questions apply, then a pyschiatrist (also assuming my previous
sentence) would have no language in common with the one possessed. 
Admittedly, that is two assumptions.
But an exorcist  (RC, Pentacostal, ...) would speak a language the
"patient" understood.  Okay, he communicates with the demon, but
through the ears of the patient, just as the "demon" communicates
through the mouth of the patient, even if sounds like another voice
it's the patient's vocal cords.
Exorcists are versed in their field (interesting question, where do
they get their experience?  Studying Vatican records?), and presumably
even more secure in their religious belief than their patient, and
talk to him  - and his demon - in strong words (docu film on an
exorcism in Germany), in words that the patient understands.  (This is
getting long, and also raises the question, if it could be accertained
that someone had been possessed who had never heard of the such?) The
exorcist threatens the demon,indirectly suggesting release for the
patient  - "salvation".  Call it maybe psycho-shock therapy. Sometimes
it works.

Last thought:  I wonder what parallels could be found when comparing
the histories of exorcised persons prior to their being possessed? 
Maybe incidents of serious transgressions, actual or mentally?   One
of the seven deadly sins in thought or deed?   (Probably not
gluttony.)  And for RC patients, I wonder what their record of going
to confession was?  Many have said that as long as people went
diligently to confession, they didn't need a psychiatrist.

myoarin-ga: Yours is a long and thoughtful comment. First, I have no
more expertise on the subject than those who have commented. Second, I
have no information on frequency of Jewish and Orthodox exorcisms,
only that both religions have rituals, as do the Roman Catholics.
Third, I am not certain one way or the other that demonic possession
is a literal reality, but I do lean toward believing it is possible.
Why? Because of the mysterious and inexplicable
phenomena associated with exorcisms. I despise, from the depths of my
being, those who label all who disagree with their views, as fools and
liars. We are expected to swallow whole the concept of the
infinitesmal singularity which contained all the matter of the
universe and exploded in the Big Bang. Where this extraordinary
particle came from and what forces packed it all in there are
unexplained. Now, I don't doubt that there are lovely mathematical
concepts that support that incredible concept, but sorry, scribbles on
a piece of paper are not reality. Anyway, I digress. You raise many
questions which I cannot answer. Don't know about the prior history of
those exorcised. Not every exorcised person was Roman Catholic. The
exorcist is not speaking "through" the senses of the patient, but
directly to the demon, if it exists. Perhaps we can all agree it is a
fascinating subject.

Are there demons and can a person be possessed of such?. The Bible
says Yes!. The account in Acts 16; 16-18, about a servant girl
possessed of a 'demon of divination' who was used by her owners for
financial gain because she was very successful in the art of
prediction. This indicates that demons can know the outcome of
business deals before they are completed. Verse 17 is interesting, in
that the demon in the girl, when the girl caught sight of the apostle
Paul, cried out "These men are slaves of the Most High God, who are
publishing to you the way of salvation". It was obviously not known to
the girl herself who Paul was, but it was very well known to the
demon. Paul, using his God given power, said to the demon " I order
you in the name of Jesus Christ to come out of her". And it came out
'that very hour'. Verses 19 and 20 state how upset and angry were the
businessmen/owners of the girl, because they lost their demon assisted
financial advantage. A second example is found at Matthew 8; 28 - 32.
Two men were possessed of a number of demons, and when the men saw
Jesus, they cried out [ actually the demons did] " What have we to do
with you, Son of God?, Did you come here to torment us before the
appointed time? The men themselves certainly did not know Jesus. And
the demons knew their time was limited [Rev.20;3, 21;8]. In verse 31,
the demons entreated Jesus, saying "If you expel us, send us forth
into the herd of swine". Jesus said "Go" and they did. Then the entire
herd rushed over a cliff and were dashed to pieces. This would have
killed the swine [pigs] not the demons, but it would have removed
their influence. Sincerely praying using Jesus' name can protect from
demonic influence. But the prayer must be to Jesus' Father, Jehovah*
God.
[Jehovah*=God's personal name= Exodus 6;3, 9;16]. 
for nelson and monroe. Disbelief and disrespect of what the Bible says
does not prove it is wrong. The above examples, which can be checked,
prove that the act of exorcism was carried out, to expel demons. It is
possible even in this modern age, for possession to happen, but only
if the person allows it, by delving into subjects, such as spiritism,
taro, etc. The Bible warns severely against such things. The Bible is
the major and primary source of all information on spiritual matters.
Demon themselves were once angels in heaven who chose to follow Satan
the Devil, who himself was once an angel, but wrongfully desired the
worship due only to God [ not Jesus]. Until Armageddon, Satan is 'the
Ruler of the World' and the world is under his influence. That is why
Satan was able to offer to Jesus 'all the Kingdoms of the world' if
only Jesus would do 'one' act of worship to him[Satan]. Jesus refused
and said to Satan, "Go away, Satan, For it is written, It is Jehovah
your God you must worship, and it is to him ALONE , you must render
sacred service". Read sensibly, these scriptures show who is Satan,
who is Jesus and who is God. Three separate entities. The demons are a
full third of all the angels in heaven who chose to follow Satan [
Rev. 12;4].

pugwasjw-ga:  Not looking for Biblical quotations...I know about them.
Looking for objectivity, not faith. I respect your beliefs; please
reciprocate.
monroe22

Pugwash,
In disregarding Nelson's opening comment, you have introduced a fair
point, I think.  The Bible is the source reference for demonic
possession - in Bible faiths - including the Jewish Tora.  Someone who
accepts the Word of the Bible literally will, I feel, be more
susceptible to demonic possession.  I get the impression that you do 
- and I don't -  so I am not going to or wanting to change you mind,
but will suggest that demonic possession could then be the expression
of a psychic disorder in someone would knew the Bible passages you
cite, whereas someone who did not know them would show other symptoms,
or maybe not develop a psychic disorder because he or she did not
suffer equivalent internal turmoils due to the absence of strict
moral/religious concepts.

Kind of unfair, I admit:  'cause he ain't got any morals, he ain't got
any problems, but should really be the one suffering from demons.

"Is there any objective, irrefutable support for the reality of
demonic possession?"  Monroe22's question.

As an Orthodox Christian, I am familiar with exorcism in the Church. I
will try to provide clarification and guidance for researching the
beliefs of the Orthodox Church.

The demonic possession of individuals and even of objects, has been
accepted by the Orthodox Church today in the Sacrament of Baptism, in
exorcising satanic powers in the case of curses, and in exorcising the
devil in the case of a possessed person. Sometimes, the exorcism
prayers for Baptism are prayed over a catechumen when he/she begins to
study Orthodoxy, such as a future convert. My priest and I said these
prayers to expel demonic powers when I became a Catechumen. He told
that Satan would focus on me to prevent me from becoming a member of
the Church. He had seen the work of the devil in a number of those
stufyingOrthodoxy.

In the early Church, the prayers, fasting and and rites were performed
through the special ministry of an exorcist. Now priests fulifill this
role.

Through our prayers and fasting, all  Christians are exorcists as we
reject evil and supress Satan's influence.

Christ is the ultimate exocist through his Resurrection, Descent into
Hell, and victory over Satan and Evil.
Satan was created by God as an angel. Satan was not created evil, but
uses his free-will to choose evil. Satan tries to influence humans to 
go against God, choosing evil.

You can read more about exorcism in the Orthodox Church on the Greek
Orthodox Archdiocese of America webpage
http://www.goarch.org/en/ourfaith/articles/article7079.asp