How I learned to love pseudoscience

[This is a transcript of the video embedded below. Some of the explanations may not make sense without the animations in the video.]


On this channel, I try to separate the good science from the bad science, the pseudoscience. And I used to think that we’d be better off without pseudoscience, that this would prevent confusion and make our lives easier. But now I think that pseudoscience is actually good for us. And that’s what we’ll talk about today.

Philosophers can’t agree on just what defines “pseudoscience” but in this episode I will take it to mean theories that are in conflict with evidence, but that promoters believe in, either by denying the evidence, or denying the scientific method, or maybe just because they have no idea what either the evidence or the scientific method is.

But what we call pseudoscience today might once have been science. Astrology for example, the idea that the constellations of the stars influence human affairs was once a respectable discipline. Every king and queen had a personal astrologer to give them advice. And many early medical practices weren’t just pseudoscience, they were often fatal. The literal snake oil, obtained by boiling snakes in oil, was at least both useless and harmless. However, they also prescribed tape worms for weight loss. Though in all fairness, that might actually work, if you survive it.

And sometimes, theories accused of being pseudoscientific turned out to be right, for example the idea that the continents on earth today broke apart from one large tectonic plate. That was considered pseudoscience until evidence confirmed it. And the hypothesis of atoms was at first decried as pseudoscience because one could not, at the time, observe atoms.

So the first lesson we can take away is that pseudoscience is a natural byproduct of normal science. You can’t have one without the other. If we learn something new about nature, some fraction of people will cling on to falsified theories longer than reasonable. And some crazy ideas in the end turn out to be correct.

But pseudoscience isn’t just a necessary evil. It’s actually useful to advance science because it forces scientists to improve their methods.

Single-blind trials, for example, were invented in the 18th century to debunk the practice of Mesmerism. At that time, scientists had already begun to study and apply electromagnetism. But many people were understandably mystified by the first batteries and electrically powered devices. Franz Mesmer exploited their confusion.

Mesmer was a German physician who claimed he’d discovered a very thin fluid that penetrated the entire universe, including the human body. When this fluid was blocked from flowing, he argued, the result was that people fell ill.

Fortunately, Mesmer said, it was possible to control the flow of the fluid and cure people. And he knew how to do it. The fluid was supposedly magnetic, and entered the body through “poles”. The north pole was on your head and that’s where the fluid came in from the stars, and the south pole was at your feet where it connected with the magnetic field of earth.

Mesmer claimed that the flow of the fluid could be unblocked by “magnetizing” people. Here is how the historian Lopez described what happened after Mesmer moved to Paris in 1778:

“Thirty or more persons could be magnetized simultaneously around a covered tub, a case made of oak, about one foot high, filled with a layer of powdered glass and iron filings... The lid was pierced with holes through which passed jointed iron branches, to be held by the patients. In subdued light, absolutely silent, they sat in concentric rows, bound to one another by a cord. Then Mesmer, wearing a coat of lilac silk and carrying a long iron wand, walked up and down the crowd, touching the diseased parts of the patients’ bodies. He was a tall, handsome, imposing man.”

After being “magnetized” by Mesmer, patients frequently reported feeling significantly better. This, by the way, is the origin of the word mesmerizing.

Scientists of the time, Benjamin Franklin and Antoine Lavoisier among them, set out to debunk Mesmer’s claims. For this, they blindfolded a group of patients. Some of them they told they’d get a treatment, but then they didn’t do anything, and others they gave a treatment without their knowledge.

Franklin and his people found that the supposed effects of mesmerism were not related to the actual treatment, but to the belief of whether one received a treatment. This isn’t to say there were no effects at all. Quite possibly some patients actually did feel better just believing they’d been treated. But it’s a psychological benefit, not a physical one.

In this case the patients didn’t know whether they received an actual treatment, but those conducting the study did. Such trials can be improved by randomly assigning people to one of the two groups so that neither the people leading the study nor those participating in it know who received an actual treatment. This is now called a “double blind trial,” and that too was invented to debunk pseudoscience, namely homeopathy.

Homeopathy was invented by another German, Samuel Hahnemann. It’s based on the belief that diluting a natural substance makes it more effective in treating illness. In eighteen thirty-five, Friedrich Wilhelm von Hoven, a public health official in Nuremberg, got into a public dispute with the dedicated homeopath Johann Jacob Reuter. Reuter claimed that dissolving a single grain of salt in 100 drops of water, and then diluting it 30 times by a factor of 100 would produce “extraordinary sensations” if you drank it. Von Hoven wouldn’t have it. He proposed and then conducted the following experiment.

He prepared 50 samples of homeopathic salt-water following Reuter’s recipe, and 50 samples of plain water. Today, we’d call the plain water samples a “placebo.” The samples were numbered and randomly assigned to trial participants by repeated shuffling. Here is how they explained this in the original paper from 1835:

“100 vials… are labeled consecutively… then mixed well among each other and placed, 50 per table, on two tables. Those on the table at the right are filled with the potentiation, those on the table at the left are filled with pure distilled snow water. Dr. Löhner enters the number of each bottle, indicating its contents, in a list, seals the latter and hands it over to the committee… The filled bottles are then brought to the large table in the middle, are once more mixed among each other and thereupon submitted to the committee for the purpose of distribution.”

The assignments were kept secret on a list in a sealed envelope. Neither von Hoven nor the patients knew who got what.

They found 50 people to participate in the trial. For three weeks von Hoven collected reports from the study participants, after which he opened the sealed envelope to see who had received what. It turned out that only eight participants had experienced anything unusual. Five of those had received the homeopathic dilution, three had received water. Using today’s language you’d say the effect wasn’t statistically significant.

Von Hoven wasn’t alone with his debunking passion. He was a member of the “society of truth-loving men”. That was one of the skeptical societies that had popped up to counter the spread of quackery and fraud in the 19th century. The society of truth loving men no longer exists. But the oldest such society that still exists today was founded as far back as 1881 in the Netherlands. It’s called the Vereniging tegen de Kwakzalverij, literally the “Society Against Quackery”. This society gave out an annual price called the Master Charlatan Prize to discourage the spread of quackery. They still do this today.

Thanks to this Dutch anti-quackery society, the Netherlands became one of the first countries with governmental drug regulation. In case you wonder, the first country to have such a regulation was the United Kingdom with the 1868 Pharmacy Act. The word “skeptical” has suffered somewhat in recent years because a lot of science deniers now claim to be skeptics. But historically, the task of skeptic societies was to fight pseudoscience and to provide scientific information to the public.

And there are more examples where fighting pseudoscience resulted in scientific and societal progress. For example, to debunk telepathy in the late nineteenth century. At the time, some prominent people believed in it, for example Nobel Prize winners Lord Rayleigh and Charles Richet. Richet proposed to test telepathy by having one person draw a playing card at random and concentrating on it for a while. Then another person had to guess the card. The results were then compared against random chance. This is basically how we today calculate statistical significance.

And if you remember, Karl Popper came up with his demarcation criterion of falsification because he wanted to show that Marxism and Freud’s psychoanalysis wasn’t proper science. Now, of course we know today that falsification is not the best way to go about it, but Popper’s work was arguably instrumental to the entire discipline of the philosophy of science. Again that came out of the desire to fight pseudoscience.

And this fight isn’t over. We’re still today fighting pseudoscience and in that process scientists constantly have to update their methods. For example, all this research we see in the foundations of physics on multiverses and unobservable particles doesn’t contribute to scientific progress. I am pretty sure in fifty years or so that’ll go down as pseudoscience. And of course there’s still loads of quackery in medicine, just think of all the supposed COVID remedies that we’ve seen come and go in the past year.

The fight against pseudoscience today is very much a fight to get relevant information to those who need it. And again I’d say that in the process scientists are forced to get better and stronger. They develop new methods to quickly identify fake studies, to explain why some results can’t be trusted, and to improve their communication skills.

In case this video inspired you to attempt self-experiments with homeopathic remedies, please keep in mind that not everything that’s labeled “homeopathic” is necessarily strongly diluted. Some homeopathic remedies contain barely diluted active ingredients of plants that can be dangerous when overdosed. Before you assume it’s just water or sugar, please check the label carefully.

If you want to learn more about the history of pseudoscience, I can recommend Michael Gordin’s recent book “On the Fringe”.