In a letter to the editor of the Journal of Near-Death Studies (Vol. 26, No. 3; Spring 2008), University of Illinois philosophy professor Neal Grossman makes some cogent points about skepticism. Unfortunately the letter is not available online, but below I'll provide excerpts. I've omitted the citations.
Grossman's letter is titled "Four Errors Commonly Made by Professional Debunkers." It's a reply to Keith Augustine, who published three articles in the Journal arguing against the view that near-death experiences are paranormal. Again, the Journal issue is not online, but a collection of Augustine's writings can be found here. His Journal articles appear to be similar, at least in part, to this long online essay.
Augustine committed the first fallacy in his very first sentence, when he claimed that ‘‘a survivalist interpretation of the phenomena … is severely undermined by the overwhelming evidence for the dependence of consciousness on the brain.’’ But that is nonsense. William James showed, more than a hundred years ago, that (1) the most that the facts of neurology can establish is a correlation between mental states and brain states and (2) correlation is not causation. The data of neuroscience will always be neutral with respect to the hypotheses of (1) causation or materialism and (2) what James called ‘‘transmission,’’ the hypothesis that the brain merely transmits an already existing consciousness into the particular form that is us. Neuroscience cannot in principle distinguish between these two hypotheses.
A second kind of error that Augustine and his fellow materialist ideologues frequently commit is to believe that a hypothesis of the form ‘‘some As are Bs’’ is refuted by producing many As that are not Bs. Survival researchers have amassed considerable empirical evidence to suggest that the hypothesis ‘‘Some NDEs involve veridical perception’’ is true. Augustine’s counterargument appeared to consist of little more than producing examples of NDEs with nonveridical perception. But the fact that some NDEs have hallucinatory features does not argue against the hypothesis that other NDEs do involve veridical perceptions....
The third fallacy involves a deep confusion between the concept of evidence and the concept of proof. Science deals with evidence, not proof. The concept of proof, of ‘‘proving’’ something with 100 percent certainty, is a concept of mathematics and logic, and has no place in empirical science.... [A]ll of science is a matter of inference, and an empirically based belief in survival is every bit as ‘‘scientific’’ as any other belief inferred from empirical evidence.
The fourth kind of logical fallacy, which I will go into in greater length, involves an equivocation between two very different meanings of the word ‘‘possible.’’
After distinguishing between a logically possible proposition - which can be any statement that is not self-contradictory - and an empirically possible proposition - which requires at least some evidential support - Grossman argues that many skeptical objections are based purely on logical possibilities. For instance, the assertion that fraud took place in a given experiment is logically possible - it is not self-contradictory - but unless there is specific evidence of fraud, or at least a clear and detailed exposition of how it could have been accomplished, there is no empirical reason to believe it.
He goes on:
Science is concerned with real possibilities only, not with mere logical possibilities, that is, not with hypotheses whose sole virtue is that they can be stated without self-contradiction....
[But the debunker] wants real scientists, who are trying to account for real data, to take as a real possibility what he himself takes as only a logical possibility, or in other words, merely imagines. The debunker wants us to refute mere logical possibilities before we can legitimately make the inference from the data to survival.
And if the fundamaterialist [Grossman's term for a "fundamentalist materialist"] says that the hypothesis of an afterlife is so extraordinary that we should prefer any other hypothesis, so long that it is consistent with materialism and not self-contradictory, my reply is as follows: There is absolutely nothing extraordinary about the hypothesis of an afterlife. The overwhelming majority of people in the world believe it, and have always believed it. I grant, however, that there exists a rather peculiar subgroup of human beings for whom the survival hypothesis is extraordinary. This subgroup consists of people who have been university-educated into accepting materialist dogma on faith.... [W]e have internalized the academy’s materialist worldview, and we call anything that falls outside that worldview ‘‘extraordinary.’’ But it is the materialists’ worldview that is truly extraordinary, especially when one considers the ridiculous hypotheses that that worldview advances in order to save itself, such as ‘‘superpsi’’ ... and nonfunctioning brains still somehow producing conscious experience.
Survival researchers are under no obligation to refute every, or even any, logically possible alternative hypothesis. Such ‘‘hypotheses’’ are nothing more than the imaginings of the fundamaterialists; the burden is on them to provide non-ideological empirical support for their hypotheses before scientists should take them seriously.
Hat tip: Chris Carter, author of Parapsychology and the Skeptics, sent me a copy of Neal Grossman's letter.
Incidentally, in 2006 I wrote my own critique of Keith Augustine's online article; it can be read here.