Unidentified Flying Object (UFO), a pseudoscience.
If I had to guess, I’d bet that readers of ‘Skeptical Inquirer’ feel fairly confident that they can identify notions that count as pseudoscientific and distinguish them from notions that don’t fall into that category. Homeopathy? Yes. Chemistry? No. Astrology? Yes. Physics? No. UFOlogy? Yes. Biology? No. And so forth.
We may disagree on some of the likely borderline cases. For instance, is SETI, the Search for Extra-terrestrial Intelligence, a pseudoscience? I’d say no, but I would understand why someone might have doubts. What about parapsychology? I’d say yes, it is pseudoscience, but, again, there may be room for disagreement.
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This general scenario seems also to be the consensus among those few philosophers who specialize on the so-called demarcation problem: the difference between science and pseudoscience. In a book chapter co-authored with my friend and colleague Maarten Boudry, for instance, I wrote, “Philosophers and scientists readily recognize a pseudoscience when they see one” (Pigliucci and Boudry 2013).
Or take Sven Hansson, another philosopher who has written on the topic:
There is widespread agreement that creationism, astrology, homeopathy, Kirlian photography, dowsing, UFOlogy, ancient astronaut theory, Holocaust denialism, and Velikovskian catastrophism are pseudo-sciences. In spite of a few points of controversy, for instance concerning the status of Freudian psychoanalysis … the general picture is one of consensus rather than controversy in particular issues of demarcation. (Hansson 2021)
We may not have found a sharp divide between science and pseudo-science –– likely because there isn’t one –– but as U.S. Supreme Court Justice Potter Stewart famously said about pornography, “I know it when I see it.”
Or maybe not. A paper authored by Kare Letrud of Inland Norway University of Applied Sciences argued based on empirical evidence that maybe we don’t know what we are talking about when it comes to pseudoscience (Letrud 2023). At least in part.
Letrud did something increasingly common among philosophers, especially those interested in science: he collected data on the issue. He looked at several papers on the topic of pseudoscience and marked every time that a particular concept, area of inquiry, or term was labelled as pseudoscientific or incompatible with pseudoscience (i.e., labelled as science, explicitly not pseudoscience, or other).
The results were very clear and, at least on the surface, a bit surprising. Only a minority of the cases that made it into his database pointed to a clear consensus among different authors that something counted as an example of pseudoscience. In most cases, there was no consensus.
The consensus cases were not unexpected: astrology, creationism, homeopathy, intelligent design, parapsychology, and UFOs. The situation was less clear for alternative medicine, ancient astronauts, climate change denialism, and several others. And there was almost no apparent consensus for a long list, including animal magnetism, the anthropic principle, anti-gravitational devices, the Bermuda Triangle, Feng Shui, cell phone radiation, and on and on.
This is more than a bit surprising. If you go through the list presented by Letrud as a multi-page bar graph and available as a spreadsheet in the supplementary materials accompanying the paper, you might be surprised at so many (to me!) obvious examples of pseudoscience, including several of those I just listed, that didn’t make the cut.
I mean, maybe we can discuss whether the anthropic principle qualifies as pseudoscience or is simply bad science (or, more appropriately, bad philosophy). But the Bermuda Triangle? I think the problem is in the details, as is often the case when surprising results emerge from empirically based research.
To begin with, Letrud tells us at the beginning of his method section that “A full review of ‘pseudoscience’ and ‘pseudoscientific’ usage in the scientific literature would be a vast and daunting task and it would presumably also have to navigate frequent polemic usage. Instead, I have chosen to review the philosophical literature; this is where one would expect to find deliberated assessments of potential pseudo-sciences.”
But arguably neither the philosophical nor the scientific literature are good places to look for the kind of data relevant to the problem Letrud is investigating. This is because most scientists and philosophers simply do not write about pseudoscience. At all. Sure enough, Letrud’s combing of the PhilPapers archive of 2.5 million titles yielded only 149 papers that could be used for his investigation. That’s a fraction of 0.00006 and pretty close to insignificant. The best source of serious writing on pseudoscience, I suggest, are the few magazines dedicated to the topic and published by organizations that are focused on the phenomenon, such as Skeptical Inquirer. Skeptics are the professionals, in this case, not scientists or philosophers, except for those very few philosophers of science who work specifically on pseudoscience, such as yours truly.
If we move from methods to results, we find that Letrud summarized his findings in the following fashion.
The potential pseudoscience cases that were discussed, referred to, or categorized by at least one of the 149 documents. Of the 511 cases, 192 were not classified by these documents as pseudo-sciences. Of the 319 cases classified as pseudoscience, 193 (approximately 60%) were classified by single documents and showed therefore no agreement between two or more documents. Of the 126 cases that were each classified as pseudoscience by at least two documents, 124 were classified as a pseudoscience by a simple majority. Sixty-two out of 319 pseudoscience cases (19%) were classified as pseudoscience by more than 3 documents (2%).
I think you can spot the problem here. A whopping 60 per cent of the entries in the spreadsheet were classified (as pseudoscience, science, not-pseudoscience, or other) in only one single paper. Of course, those instances could not show any agreement with other papers, because those entries were unique. Many of the other cases included situations in which the term to be classified was mentioned in only two papers. The lack of consensus on most entries, therefore, is an artefact resulting from many of the corresponding concepts being mentioned very rarely in the literature surveyed by Letrud. It’s not that people don’t agree that, say, feng shui is a pseudoscience. It’s that very few of the (very small) group of philosophers interested in pseudoscience mentions feng shui at all!
I went to the supplementary materials and downloaded the spreadsheet made available by Letrud, which confirms that the data are very, very sparse. This is to be expected, because the papers in question are not catalogs of pseudoscience but conceptual discussions of the demarcation problem and surrounding topics.
Just to give you an example, one of the papers that made it into Letrud’s database was published in 1980 by R.P. Thompson in the Proceedings of the Biennial Meeting of the Philosophy of Science Association. The title is “Is Sociobiology a Pseudoscience?” It mentions only two examples of pseudoscience: astrology and biorhythms. It also mentions one example of a field the author considers a science; sociobiology. That’s it! We are simply given no information about what Thompson thought about all the other entries in the table (a total of 511), which cannot be taken as evidence that he doesn’t think, say, that homeopathy is pseudoscience. This is truly a case where absence of evidence is not evidence of absence.
Alternatively, consider one of the examined concepts: the Bermuda Triangle. In the 149 papers, it is mentioned exactly four times: two as pseudoscience, one as not science, and one as undetermined (if I understand the legend of the table provided). One of the pseudoscience labels comes from a paper published in Minerva, a journal covering the sociological study of scientific knowledge and research, the other from a chapter in the collection on pseudoscience edited by Boudry and me. The non-pseudoscience classification originates from a paper published in Science & Education. And the undetermined label is from a book titled The Logic and Methodology of Science and Pseudoscience. The notion of the Bermuda Triangle appears nowhere else in the database. One simply cannot tell, on the basis of these scant data, whether there is a consensus about the Bermuda Triangle or not. I bet, however – and admittedly this is only intuition on my part – that most skeptics will readily agree that this is indeed an example of pseudoscience.
The above notwithstanding, I think Letrud is right in advising, near the end of his paper, that for the purpose of testing candidate criteria for demarcating science from pseudoscience it may be best to focus our attention on the clear cases: homeopathy and astrology over here, physics and biology over there. The problem is that the most interesting stuff to be learned lies in between the two, SETI, anyone?
Courtesy” ‘Skeptical Inquirer’ – July 2024
