Possibility versus Probability (original) (raw)
Possibility versus Probability by Daniel H. Caldwell
In a web version of his book The Unknowing Sage, David C. Lane wrote:
". . .I have yet to unearth an airtight, empirical case for genuine psychic powers. There are always some uninspected loopholes which reveal that natural (versus supernatural) processes were involved. I realize that my skepticism will turn off a number of parapsychology buffs. . . . ."
Lane says that he has not discovered one airtight case for genuine psychic powers; and that in all such cases "uninspected" [unsuspected?] loopholes indicate that natural processes were involved.
Exactly how does Lane define "airtight"? One dictionary defines "airtight" as: "having no noticeable weakness, flaw or loophole." Italics added.
But are those loopholes mentioned by Lane actually noticeable and real or only theoretical possibilities?
Furthermore, if by "airtight" Lane wants to convey the meaning of perfect, flawless, 100% confirmed, then I would say he is living in a "fairytale" world. What is completely flawless? For example, is there a medical test in the world that will give accurate results anytime, anywhere, under any and every condition?
In an unpublished manuscript of mine, I have a chapter titled "POSSIBLE FLAWS: There Must be an 'Error Some Place'." In this manuscript I quote an extract from Deviant Science: The Case of Parapsychology by James McClenon where he is writing about the critic's strategy of "unpacking" any successful parapsychological experiment.
"The goal of the critic using this strategy is to 'unpack' and examine in detail any experiment, and to demonstrate how methodological flaws could have entered into the experimental process, thereby producing an invalid results. . . . The critic ...thinks of some...methodological flaw that could have occurred. . . .His or her 'unpacking' of methodological assumptions tends to render the experiment into an anecdotal form. . . .This unpacking strategy makes the 'perfect' ESP experiment an impossibility. Sooner or later, the critic will ask for information that is no longer available, or for a degree of experimental control and exactitude that is desirable in principle but impossible in practice. . . .[Another] rhetorical ploy is to demand total perfection. It is always possible for critics to think of more rigid methodological procedures after an experiment has been conducted. . . . The a priori arguments of the critics mean it is highly logical to assume that, within all experiments which successfully 'prove' the existence of psi, there must be an 'error some place'." Italics added.
Ray Hyman, a psychologist and skeptic of the paranormal, has agreed that in using such a method of argument, "it is always possible to 'imagine' some scenario in which [for example] cheating [or lying], no matter how implausible, could have occurred." Italics added
But using such a method is illegitimate, as Marcello Truzzi (a sociologist and another skeptic of the paranormal) points out, because by its use, "one can 'hypothetically' explain away any result [even] in science." Italics added.
One can, no doubt, look for "unsuspected" flaws in regular scientific experiments. Is there even one experiment in science that has no possible flaws?
In effect, this type of argument and the process of unpacking an experiment or a testimonial account becomes a game in which the critic cannot lose.
Turning to the realm of historical inquiry, the historians Jacques Barzun and Henry F. Graff point out in their book The Modern Researcher:
"If you receive a letter from a relative that [1] bears what looks like her signature, that [2] refers to family matters you and she commonly discuss, and that [3] was postmarked in the city where she lives, the probability is very great that she wrote it."
"The contrary hypothesis would need at least as many opposing signs [of evidence] in order to take root in your mind---though the possibility of forgery. . .is always there." Italics added.
Please note that the hypothesis that the letter is really written by your relative is supported by three positive signs of evidence. But as Barzun and Graff point out, even in spite of all that, the possibility of forgery is always there.
A critic using the unpacking method could take the ball at this point and try to explain away the three pieces of evidence.
For example, the skeptic could argue:
"Isn't it possible that [1] the relative's signature was forged, and, isn't it possible that [2] some "forger" was somehow privy to family matters, and, furthermore, isn't it possible that [3] the forger could have mailed the letter in the city where your relative lives to throw you off the track?"
And if you objected to such speculation, the critic might respond:
"Prove to me that the three statements, I just listed, aren't possible. Didn't Barzun and Graff admit that the possibility of forgery. . . is always there?"
But one should point out that possibilities and plausibilities [at _step 2_ in the Four Step Process of Discovery] are not to be confused with probabilities [at _step 4_]. Barzun and Graffe clearly enunciate an important dictum for the researcher:
"The rule of 'Give Evidence' is not be be violated. . . .No matter how possible or plausible the author's conjecture [at step 2 in the 4 step process] it cannot be accepted as truth [at step 4] if he has only his hunch [which is not evidence] to support it. Truth rests not on possibility or plausibility but on probability. Probability means the balance of chances that, given such and such evidence [at step 3], the event it records happened in a certain way; or, in other cases, that a supposed event did not in fact take place." Italics added.
Unfortunately, far too many critics of the paranormal (not to mention other subjects) become fixated on possibilities and never progress beyond to considering probabilities. Such skeptics---after pointing out that if two or more explanations are possible, none are proved---seem to be uninterested in the question of where the weight of the evidence lies. Many of these critics fixate and speculate on various possibilities at step 2---hoping that readers will assume that something has been proven or disproven by such rhetoric.
So when David Lane writes: ""I have yet to unearth an airtight, empirical case for genuine psychic powers. There are always some uninspected loopholes which reveal that natural (versus supernatural) processes were involved," is he referring to "possible" loopholes that he has conjured up in his imagination or is he talking about loopholes that can be documented with evidence?
I close this article by giving three examples of the unpacking strategy and of the method of argument by possibilities:
Example 1: http://groups.yahoo.com/group/theos-talk/message/4423
Example 2: http://groups.yahoo.com/group/theos-talk/message/6173
Example 3: http://groups.yahoo.com/group/theos-talk/message/6146
