Date: Tue, 11 Nov 1997 16:51:05 -0800 (PST) From: Bob Steiner To: Rick Moen Subject: Re: Proving a Negative Hi Rick: Many thanks for offering to make Giraffe available at the BAS website. Forgive me: I know not about Clipboards. I hope the following will suffice. Thank you. All best wishes. Bob I Am Not a Giraffe, And I Can Prove It by Bob Steiner E-mail: bsteiner@crl.com (c) 1996 by Bob Steiner Originally published in _BASIS_, Newsletter of Bay Area Skeptics, April 1996. Editorial Note: A single underline (_) is a toggle to start/stop italics. It keeps coming back like a bad penny. I have seen it over and over in skeptical writing, and have heard if from skeptical speakers. A skeptic will present a persuasive, logical case why one should not believe in the paranormal: lack of credible evidence, the appearance can be duplicated by normal means, and the like. Then a parapsychologist will say--correctly, "The fact that a magician can duplicate the appearance of this claimed paranormal event does not prove that the psychic did not do it psychically." The skeptic will step into the trap by replying, "That is true," then hasten to add, "but you cannot prove a negative." I have not seen it yet, but the day will come when some astute parapsychologist will _prove_ to the audience that one can indeed prove a negative. Thence, having captured the _merited_ respect of the audience on that one point, the parapsychologist will extrapolate and will successfully convince the audience that the skeptic has no credibility and should not be believed on anything else said. All of this because the skeptic made a strong, all-inclusive, universal assertion--and it was wrong! I have on my desk _The Encyclopedia of the Paranormal_, edited by Gordon Stein, published by Prometheus Books, Amherst, New York, and just released moments ago. My initial scanning (I just received it today) indicates that it is an excellent work. In one otherwise well-written essay, the author concludes with: It would seem that with all the evidence of trickery we should come to the conclusion that PK-MB [psychokinetic metal bending] is nothing more than a myth, skilled magicians using their five normal senses to create the illusion of reality. The problem is that it is impossible to prove a negative. In a letter to the editor in the July/August 1995 _Mensa Bulletin_ [Fort Worth, TX. America Mensa, Ltd.], a writer attempts to nail down his point by invoking this all-inclusive, erroneous generalization. The particular topic at issue in the letter is less important than the flaw in philosophical reasoning by an otherwise logical writer: Not only is the [person who does not believe] under no obligation to do anything, it's impossible for him to prove that [the topic at issue] has no existence. This is due to that ironclad logical rule that says "One cannot prove a negative." In writing and discussion, it is sometimes appropriate to explain the difficulty (or even the impossibility) of proving _some_ negatives. It is an unjustifiable stretch to jump to the universal declaration that "it is impossible to prove a negative." I can prove that the world is not flat, that there cannot be an undiscovered continent on Earth larger than North America, that there is no elephant in my living room, that I am not a woman, that I am not a giraffe, and that two parts of hydrogen plus one part of oxygen do not produce sulfuric acid.