Saturday, May 30, 2009

Karl Popper on Falsifiability

It is often said that for a theory to be scientific it must be falsifiable.

This thinking comes from the work of philosopher Karl Popper.

Popper noticed that there were some theories that seemed to be able to explain everything within their scope. No matter what conceivable situation you imagined, the theory could explain it. True believers would consider this universal application as confirmation of the theory. Popper did not agree. He recognized that the theory might be true, but it can only be confirmed if it can pass a test where failure of the test would disprove the theory. This means a theory can only be confirmed if it can be falsified. If a theory can't be falsified, it might be true but it can't be confirmed.

Science involves testing hypotheses through empirical means, either through experiment or observation. For a theory to be scientific it must be confirmable by empirical means. According to Popper, for a theory to be confirmed it must pass a test in which failure would falsify the theory. Therefore, a scientific theory must be falsifiable, otherwise it cannot be confirmed by empirical means.

This view distinguishes theories that are simply consistent with the evidence from theories that are supported by evidence. It is about whether a theory can be confirmed and how to confirm it. It is not about whether a theory is true or false - an unfalsifiable theory might be true. Unfalsifiability simply means a theory is not supported by empirical evidence even if there is a vast amount of evidence consistent with the theory.

Popper described how he developed this philosophy in the article:

Science, Pseudo-Science, and Falsifiability by Karl Popper, 1962

In the article Popper, explained how vacuous theories are always confirmed:

I may illustrate this by two very different examples of human behaviour: that of a man who pushes a child into the water with the intention of drowning him; and that of a man who sacrifices his life in an attempt to save the child. Each of these two cases can be explained with equal ease in Freudian and Adlerian terms. According to Freud the first man suffered from repression (say, of some component of his Oedipus complex), while the second man had achieved sublimation. According to Adler the first man suffered from feelings of inferiority (producing perhaps the need to prove to himself that he dared to commit some crime), and so did the second man (whose need was to prove to himself that he dared to rescue the child). I could not think of any human behaviour which could not be interpreted in terms of either theory. It was precisely this fact -- that they always fitted, that they were always confirmed -- which in the eyes of their admirers constituted the strongest argument in favour of these theories. It began to dawn on me that this apparent strength was in fact their weakness.

He contrasted this with Einstein's theory of relativity which could be tested. If the theory didn't pass the test, it would be proven false.

With Einstein's theory the situation was strikingly different. Take one typical instance -- Einstein's prediction, just then confirmed by the findings of Eddington's expedition. Einstein's gravitational theory had led to the result that light must be attracted by heavy bodies (such as the sun), precisely as material bodies were attracted. As a consequence it could be calculated that light from a distant fixed star whose apparent position was close to the sun would reach the earth from such a direction that the star would seem to be slightly shifted away from the sun; or, in other words, that stars close to the sun would look as if they had moved a little away from the sun, and from one another. This is a thing which cannot normally be observed since such stars are rendered invisible in daytime by the sun's overwhelming brightness; but during an eclipse it is possible to take pictures of them. If the same constellation is photographed at night one can measure the distances on the two photographs, and check the predicted effect.

Popper explained that a theory is only confirmed by a passing test that if failed would falsify the theory.

Every genuine test of a theory is an attempt to falsify it, or to refute it. Testability is falsifiability; but there are degrees of testability; some theories are more testable, more exposed to refutation than others; they take, as it were, greater risks.

Confirming evidence should not count except when it is the result of a genuine test of the theory; and this means that it can be presented as a serious but unsuccessful attempt to falsify the theory.

He compared the psycho-analytic theories to relativity.

The two psycho-analytic theories were in a different class. They were simply non-testable, irrefutable. There was no conceivable human behaviour which could contradict them. This does not mean that Freud and Adler were not seeing certain things correctly; I personally do not doubt that much of what they say is of considerable importance, and may well play its part one day in a psychological science which is testable. But it does mean that those "clinical observations" which analysts naïvely believe confirm their theory cannot do this any more than the daily confirmations which astrologers find in their practice.

He concludes:

Thus the problem which I tried to solve by proposing the criterion of falsifiability was neither a problem of meaningfulness or significance, nor a problem of truth or acceptability. It was the problem of drawing a line (as well as this can be done) between the statements, or systems of statements, of the empirical sciences, and all other statements -- whether they are of a religious or of a metaphysical character, or simply pseudo-scientific. Years later -- it must have been in 1928 or 1929 -- I called this first problem of mine the "problem of demarcation." The criterion of falsifiability is a solution to this problem of demarcation, for it says that statements or systems of statements, in order to be ranked as scientific, must be capable of conflicting with possible, or conceivable, observations.
Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Studying Personal Experiences

The psychical researchers of the late 19th century wanted to extend the methods of science so that personal experiences could be studied quantitatively and objectively.

Their first attempt was to use a survey to help make sense of anecdotal information about crisis apparitions. The survey was called "the census of hallucinations". They tried to do a representative survey of the British population asking a simple question:

"Since January 1, 1874, have you when in good health, free from anxiety, and completely awake had a vivid impression of seeing or being touched by a human being, or of hearing a voice or sound which suggested a human presence, when no one was there ? Yes or no ?"

If a subject answered yes, they requested further information. If the event seemed to include veridical information, they sought corroborating testimony from other witnesses such as family members to whom the subject described the hallucination at the time it occurred.

This is described in: "Phantasms of the Living" by Edmund Gurney, Volume 2 Chapter XIII "The Theory of Chance Coincidence"

Next, using sources of information on the frequency of deaths such as "Supplement to the 45th Annual Report of the Registrar-General", they calculated the expected probability of having a hallucination near the time of death of a relative or acquaintance. From this they were able to demonstrate that the frequency of crisis apparitions (seeing an apparition of someone near the time of their death) was much too high to be explained by chance coincidence.

The census of hallucinations is also described in The Proceedings of the Society for Psychical Research. Many articles on the census can be read in the Proceedings on line at books.google.com. These articles can be easily found using the Web Guide to the PSPR on my web site:

Unfortunately, the ambition of extending the scientific method to the study of personal experiences withered when a new generation of researchers turned toward easily replicable laboratory experiments when that methodology had come into vogue in the 20th century.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Friday, May 29, 2009

Mrs. Piper's Control Spirit, Phinuit

Lenora Piper was one of the most investigated mediums of all time. In a previous post ( Mrs. Piper: Evidence for Survival After Death ) I described how it was proved she was psychic, precautions investigators took to rule out fraud, and why it was believed that she obtained information from spirits rather than through telepathy.

Was Phinuit a Spirit?

One uncertainty about Mrs. Piper's mediumship that I have felt was unfair was the suggestion that one of her control spirits, Phinuit, was not really a spirit but an alternate personality of the medium. It seemed to me that other spirits, who gave a lot of evidential material, acknowledged he was a spirit. That seemed to be strong evidence in favor of him being a genuine spirit.

I was reading the 1898 report by Richard Hodgson in the Proceedings of the Society for Psychical research and I saw that Hodgson made the same point:

A Further Record of Observations Of Certain Phenomena of Trance by Richard Hodgson L.L.D. Proceedings of the Society for Psychical Research Vol. XIII. 1898, p 284 - 582

On page 369 Hodgson wrote:

Now, to give Phinuit his due, notwithstanding all his shortcomings and delinquencies, I was inclined to think, even before the publication of my previous report, that Phinuit believed himself to be a "spirit." (Proceedings, Vol. VIII., p. 57.) But there was so much that was inferior about him that one could not attribute any force, on the ground of either his intelligence or his sincerity, to his persistent affirmations that he was a "spirit" and giving communications from "spirits." But we must, I think, allow some weight to such statements when they are made persistently by a continually increasing number of coherent personalities manifesting directly through Mrs. Piper's trance, and characterised by a high moral tone, a pervading sincerity, and a deep earnestness of purpose, who individually insist that they are the persons we knew in bodies incarnate; when they all make their statements from the point of view that would naturally belong to such persons under the conditions in which they claim to be; and when they stoutly resist any suggestions to the contrary. Those who adopt the hypothesis of telepathy from the living must clearly recognise the fulness and completeness of many of the personalities which they suppose to be fictitiously formed in connection with Mrs. Piper's trance, and the inversion, as it were, of the conceptions of living persons; so that there is produced this marvellous simulation of the "deceased," accompanied not only by their specific memories, but by the presentation of each character in its unity, showing a clear self-consciousness, a working intelligence of its own, and a morality in no case less than that of the persons concerned when living, but showing rather a more definite upward movement, a stronger determination towards the "things that are higher." And yet with all this apparently complete independence and power of reasoning and lofty ethical aspirations, they must be regarded as either lying or mistaken about the fact of their existence itself, and must be assumed to be, one and all, merely fragments of Mrs. Piper.
Hodgson is saying that the spirits who communicated through Mrs. Piper and proved their identity said that Phinuit was a spirit. Since they were the spirits of reliable people and therefore unlikely to lie, it is reasonable to conclude that Phinuit really was a spirit.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Thursday, May 28, 2009

Spiritualism and Science

Dean Radin's blog has a new post: My faith was broken ...

It's about criticism published elsewhere on the internet of the NPR story I blogged about a few days ago. The criticism argued that parapsychology is an attempt to use science to support religion.

I thought that was amusing.

To a Spiritualist, the idea that parapsychology is a means of supporting religion is comical.

While parapsychologists are struggling with small effect sizes and decline effects in their labs, and at the same time debating the merits of the the super-psi hypothesis to explain the evidence for the afterlife, spirit communication and spiritual healing are facts of every day life for Spiritualists.

The ancient Egyptians built the pyramids without scientists, the Romans built roads across Europe without scientists, the Chinese developed gunpowder, and movable type without scientists. Ships sailed across the seas long before Bernoulli discovered the principle which explained their motion. In certain fields of endeavor, science is not necessary. As any shaman knows, psi is one of them. In fact, our understanding of psi would be further advanced without Science because mainstream science has only hindered research on psi.

For 150 years, while Science has been ignoring psi, Spiritualists have been demonstrating psi, educating people about psi, and training people in the use of psi. During that entire period, Science has been trying to deny the existence of psi. When it comes to psi, there is more intellectual honesty in Spiritualism than mainstream science.

Parapsychology and psychical research are interesting and I hope eventually they will increase our knowledge about psi. But, even though you can find support for Spiritualism in psychology, parapsychology, and quantum physics, right now, Spiritualists are years ahead of the scientists when it comes to using psi. Parapsychologists will find more support for their science in a Spiritualist church than a Spiritualist will find support in parapsychology labs for many years to come.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Wednesday, May 27, 2009

Transition After Death

Michael Tymn has a new blog post: What is the "Second Death"?

In this article, Michael Tymn describes a transition stage spirits go through. It starts immediately after death and lasts up to a few days. During this stage the spirits are often confused, but they become mentally clear after the transition is completed. The completion of this transition is sometimes called "the second death".

Based on what I have learned of the subject, I definately agree that this transition stage occurs. But, I wouldn't use the same term for it. "Second death" sounds traumatic. What actually happens is not at all traumatic. It is more like an awakening than a death.

Richard Hodgson, who studied the trance medium Mrs. Piper, reported that spirits would communicate through her in a confused manner for the first few days after death. This seems to indcate that there is a short transition phase for new spirits. I discussed this in a previous post: Mrs. Piper: Evidence for Survival After Death. This transition stage was one reason Hodgson thought Mrs. Piper's mediumship was really due to spirits rather than telepathic perception of thoughts from the sitters. The quality of communication varied with this characteristic of the spirit (the length of time since death) rather than some characteristic of the sitters. Sitters might have many spirits communicating with them through Mrs. Piper, but only the recently dead would be confused.

I also know an objective clairvoyant medium (she see's spirits in the room with her) who finds it easier to communicate with new spirits before they complete the transition even though the new spirits are often confused. She reports that initially spirits are in what sounds to me like an "earth bound" condition, but when they adapt to their new reality, they move on to what might be called a "higher state". After this transition, they appear to her less like the physical beings we are when incarnated and they commuincate more with images than words. This seems consistent with something Michael Tymn reports as also being a part of the second death. During that process, one layer of a series etherial bodies is shed.

It's a very intersting blog post and well worth reading.

Tuesday, May 26, 2009

Web Guide to the Proceedings of the Society for Psychical Research

I have added a Web Guide to The Proceedings of the Society for Psychical Research to my web site. It's a web page with the tables of contents of the volumes of the Proceedings that are available to view on line at books.google.com. You can search through the tables of contents and if you find an article that interest you, there is a link to the same volume at books.google.com where you can click on a link to view the article. This link will take you to the Web Guide

Sunday, May 24, 2009

Faith In Psi

Can parapsychology help people understand their own spontaneous psychic perceptions?

When people experience a synchronicity, they often think it is a sign telling them something. A Spiritualist might say it is due to the influence of spirit guides. Gary Schwartz might say it is evidence of a Guiding Organizing and Designing (G.O.D.) force in the universe. I think most parapsychologists would say that it is due to unconscious psi.

If the parapsychologist is right and it is unconscious psi, should it still be interpreted as a sign? Here's an example to illustrate the question: At one time I was unhappy with my job, and during that time, for some unknown reason I decided to go somewhere that was very uncharacteristic of me to go. While I was there, I met someone I knew and that meeting led to a job offer allowing me to leave the job I was unhappy with.

The Spiritualist or Gary Schwartz might say in that situation I should take the new job because there is a benevolent intelligence leading me into the coincidence

Assuming this situation is not just a coincidence due to chance, what does parapsychology say about it? Can a person rely on their unconscious psi to work for their highest good? How far can they trust it? Would it definitely be in their long term interest to change jobs or might it solve a short term problem but in hindsight turn out to be a bad decision after all? Will a foolish person use unconscious psi for their short term benefit without regard to the long term consequences? If someone had self destructive tendencies could their unconscious psi act to their detriment rather than for their benefit?

I suspect many parapsychologists assume psi is good. If a synchronicity occurs, don't they assume they used psi unconsciously for their own benefit? But isn't that just like believing benevolent spirit guides or a G.O.D. force set up the synchronicity? Don't parapsychologists have faith in psi the same way many religious people have faith in a higher power? It seems that parapsychologists have "faith" not in spirits but in psi. It is a sort of awe of the paranormal as opposed to the supernatural.

However, the Spiritualist might attribute negative consequences of a paranormal event to undeveloped spirits leading them astray. Parapsychologists often attribute poltergeist phenomena to unconscious psi, so they must believe that sometimes unconscious psi can be due a result of mental dysfunction and is not necessarily a product of "higher intuition". But I am not aware that parapsychologists have any lore to warn them when to be wary of unconscious psi in the form of synchronicities, gut feelings, or premonitions.

It seems to me that this is one of the areas parapsychology might make a significant contribution. If they can understand how unconscious psi might be used for good or ill, that might help the average person decide what to do when faced with a "sign from God". It would be an important application of the science in the every day life of the individual. It would demonstrate parapsychology's superiority over the Spiritualist or G.O.D. world view.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Saturday, May 23, 2009

Telekinesis Proved In 1871


William Crookes tested the psychic Daniel Dunglas Home in 1871 and proved telekinesis is real. He tested Home in laboratory conditions that prevented fraud. Crookes even jumped up and down on the apparatus to prove it couldn't be moved by Home if he tried to cheat.

Crookes' book, Researches into the Phenomena of Modern Spiritualism, has diagrams of the equipment and wind-up chart recorder graphs showing the spontaneous movements.

It even has a drawing of the cage in which the accordion was seen to be playing itself.

Here is a link direct to the relevant chapter.

Copyright © 2009, 2013 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

NDE Evidence for survival

Do Any Near-Death Experiences Provide Evidence for the Survival of Human Personality after Death? Relevant Features and Illustrative Case Reports
EMILY WILLIAMS COOK, BRUCE GREYSON, AND IAN STEVENSON Journal of Scientific Exploration, Vol. 12, No. 3, pp. 377-406, 1998

The article discusses the characteristics of NDEs that are most likely to provide evidence of survival of consciousness. It concludes that certain features of NDEs when occuring together in the same experience provide strong evidence of survival. These features are:

  • Vivid imagry and sensations at a time of decreased physiological functioning.
  • Out of body experience.
  • Perception of verifiable information that would not be obtainable through the normal senses.

Individually these characteristics might be explainable by other means but together they argue strongly for survival. Several NDE cases are described. The paper spells out the type of evidence that would argue for survival, but they do not conclude that currently available evidence is sufficient to prove survival. This is because of a lack of cases investigated with sufficient rigor.

From the article:

One of the main reasons that near-death experiences have generated so much interest in recent years among the general public is because they seem to provide evidence that consciousness survives the death of the physical body.

...

We describe three features of NDEs - enhanced mentation, the experience of seeing the physical body from a different position in space, and paranormal perceptions - that we believe might provide convergent evidence supporting the survival hypothesis. We then describe 7 published cases and 7 cases from our own collection that contain all three features. These cases are all -with one possible exception - some what deficient with regard to their recording and investigation, but they exemplify the type of case that should be identified earlier and investigated more thoroughly than these have been, and that may then help us decide the extent to which NDEs can contribute to the evidence for survival of consciousness after death.

...

In sum, the NDE features that seem to us to have the most potential for contributing to the evidence suggesting survival after death fall into three broad categories. First, there are those features suggesting enhanced mentation at a time of diminished physiological functioning, including a rapid, detailed, and often extremely vivid revival of memories (Stevenson & Cook, 1995), complex and vivid imagery and sensations, and lucid cognitive functioning. Second, there is the experience of viewing one's physical body and the immediate environment as if from a spatial location different from that of the physical body. Finally, there are those cases in which the person has gained previously unknown but potentially verifiable information, usually either by viewing distant events or by meeting deceased persons. The first group of features suggests that mental clarity is not entirely dependent on physiological functioning; the second suggests that consciousness can function apart from, if not independently of, the physical body; and the third group suggests that NDEs are not entirely subjective in origin. Separately, none of these features provides compelling evidence for the survival of consciousness after death, since they all might be explained by other normal or paranormal mechanisms. Taken together, however, and particularly when all three types of features occur together in individual cases, the hypothesis of survival begins to seem more worthy of consideration.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Can Positive Thoughts Help Heal Another Person?

Npr.org has an interesting article on the healing power of thought.

Can Positive Thoughts Help Heal Another Person?
by Barbara Bradley Hagerty

In the mid-1990s, when having HIV was akin to a death sentence, Ironson noticed that a number of patients like Kaplan never got sick. Ironson wanted to know why. And she found something surprising.

"If you ask people what's kept you going so long, what keeps you healthy, often people would say spirituality," she says. "It was something that just kept coming up in the interviews, and that's why I decided to look at it."

The article also describes research being done by Dean Radin:

After running 36 couples through this test, the researchers found that when one person focused his thoughts on his partner, the partner's blood flow and perspiration dramatically changed within two seconds. The odds of this happening by chance were 1 in 11,000. Three dozen double blind, randomized studies by such institutions as the University of Washington and the University of Edinburgh have reported similar results.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Michael Prescott: Everything old is new again

Michael Prescott has reposted a great article exposing an example of skeptical deception:

Everything old is new again: Let's get Serios
by Michael Prescott

The article discusses Ted Serios who could psychically impress images on photographic film. Prescott exposes not one but two skeptics who tried to debunk Serios and made no mention of the the fact the Serios worked under controlled conditions that prevented fraud. One of the skeptics even listed the conditions but said they were a "preposterous set of controls" included in a challenge to him to try to produce the phenomena by ordinary means. He made no mention of the fact that the psychic he was trying to debunk worked under those conditions.

Copyright © 2009 by ncu9nc All rights reserved. Texts quoted from other sources are Copyright © by their owners.

Mrs. Piper: Evidence for Survival After Death

Mrs. Piper: Evidence for Survival After Death

Mrs. Piper, a trance medium, was one of the most tested mediums of all time. In the Proceedings of the Society for Psychical Research in 1898, her primary investigator, Richard Hodgson, published the opinion that her mediumship was most likely due to communication from spirits.

Precautions Against Fraud

Richard Hodgson was a skeptic. He had investigated Madam Blavatsky and exposed her as a fraud. Hodgson's investigation of Mrs. Piper proved she was psychic. Her trance was genuine, it was not a normal state of consciousness. She gave sittings under controlled conditions. Sitters were not introduced to her by their correct names and most of the sitters were unknown to her. While she was in trance, she gave correct information about deceased individuals she could not have elicited by means of cold reading. She was watched by detectives and her mail was read to prove she did not investigate sitters before their sittings.

There was no doubt that Mrs. Piper was psychic. By the time Hodgson published his report, the main question in the minds of psychical researchers was whether she obtained her information through telepathy and unconsciously mimicked the personality of spirits or whether her mediumship was genuine communication from spirits. Hodgson's opinion, based on his extensive records of sittings and many hours attending sittings with the medium, was that her mediumship was genuine communication with spirits.

Evidence for Survival After Death

Hodgson's Five Main Points of Evidence For Survival After Death

Hodgson gave these five main reasons why he favored survival after death over telepathy as an explanation for Mrs. Pipers mediumship:

  1. Skill in communicating varied with the spirit not the sitters. If Mrs. Piper obtained information from the sitters by telepathy, the quality of the information should vary with the sitter not the spirit.

    • Some spirits were never good at communicating.

    • Some spirits were better than others at communicating names.

    • During otherwise successful sitting where some spirits were able to communicate clearly, sometimes certain spirits well known to the sitters were not able to communicate clearly. This often occurred with spirits who had suffered from a long illness or a mental disturbance at the time of death. This confusion in a communicator was sometimes unexpected by the sitters particularly when the person was noted for clear thinking in life.

  2. All spirits had trouble communicating at first but improved with practice.

    • This occurred even when the sitters were experienced and had had other spirits come through.

    • Difficulty in communicating could be overcome with the assistance of other spirits. Telepathy does not explain this.

  3. Spirits seemed to be confused for a few days just after death.

    • This confusion was not due to changing the sitters. It occurred when the sitters remained the same.

  4. Stray thoughts from the spirits (not the medium or sitter) seemed to leak through into the communications if the spirit was having difficulty communicating.

    • These thoughts reflected subjects that would be of particular concern to the spirit such as situations involving living relatives but which were unknown to the sitters.

    • These stray thoughts were thought to explain some of the seeming failures of spirits to correctly answer questions aimed and proving their identity. This is not explained by telepathy.

    • When spirits communicated by writing and controlled the medium themselves, confusion was apparent. When spirits communicated indirectly through speech by the spirit control Phinuit, confusion on the part of the spirit was obscured because Phinuit was acting as an intermediate. This explains some of the failures of spirits to correctly answer questions aimed at proving their identity, and explains some instances when Phinuit was inaccurate. This is also not explained by telepathy.

  5. Characteristics of children communicators

    • The spirits of young children recently deceased had clearer memories of early childhood than spirits who had died many years before. This was not explainable by telepathy because the the sitters often had clear memories of the spirit's early childhood.

    • Spirits of young children recently deceased tended to communicate more clearly than adults recently deceased. This is not explained by telepathy.

    • Spirits of individuals who died in childhood express themselves as though they had grown during the intervening time. This occurred even when they were still thought of as young children by the sitters.

Other Evidence Not Consistent With Telepathy

  1. Spirits unrelated to sitters sometimes came through to give messages to friends not present at the sitting.

  2. Spirits responded to questions intended to prove their identity correctly but not always in ways the sitters expected. For example, a spirit was asked for a nickname of another person and replied with a nickname that had been used but was not the one expected by the sitter.

  3. Sometimes the communicating spirit was unable to give information that was in the conscious mind of the sitter. This is inconsistent with telepathy.

  4. On occasion, a spirit would not know the name of a sitter they were thought to know. This suggests telepathy was not occurring.

  5. Difficulty in communicating names was a common characteristic of Mrs. Piper's mediumship. This is also inconsistent with the hypothesis of telepathy.

  6. If the investigator ran the sitting like a telepathy experiment, less evidential information was given through the medium. If he treated the spirit like an actual person communicating under adverse conditions, the communication was improved. Beneficial treatment included maintaining a soothing manner, and letting the spirit say what he chose rather than subjecting him to a cross examination.
Richard Hodgson's report on Mrs. Piper is available to view or download on-line.

A FURTHER RECORD OF OBSERVATIONS OF CERTAIN PHENOMENA OF TRANCE by Richard Hodgson L.L.D. Proceedings of the Society for Psychical Research Vol. XIII. 1898, p 284 - 582

Article p. 284.

Table of Contents for Volume XIII.

Section: Indications That The Spirit Hypothesis is True, p 370.

Summary of Evidence for the Spirit Hypothesis: bottom of p. 391.