Recognizing Pseudoscience

Sven Ove Hansson - 1 August 1989

Reprinted from the British and Irish Skeptic.

Historically man has sought to know the world through two diametrically opposed methods: introspection, and what we will here call “extrospection.” By “extrospection” we mean drawing conclusions from what you perceive with your senses. This is the source of everyday knowledge and, carried out systematically, of scientific knowledge. Introspection, or the search for knowledge about the world inside yourself, is common to many different forms of mysticism. In the last few years, Fritjof Capra and other well-known proponents of mysticism have claimed that through meditation one can arrive at the important results of modern physics.

One major difference between introspection and extrospection lies in the ways they lend themselves to external agreement. When different people use introspective methods to seek knowledge, they may very well arrive at different conclusions. Since their sources of intuition are not communicable, the people have no common language with which to convince each other. In practice, then, the mystics have two alternatives. One is to fully accept their differences and make no attempt to arrive at a consensus. In our world of socially interdependent individuals, more often than not this is impracticable. The other alternative, and the one mystics more generally choose, is to regard one person’s intuitions as the most accurate. Used this way, the introspective method leads to authoritarianism.

The extrospective method, on the other hand, yields essentially the same results when different people apply these methods. As a philosophical realist, I would say that this is because, though the “inner worlds” reached by introspection may very well differ, we all live in one and the same external world. If two people have different opinions about the weights or lengths of different objects, they can reach a consensus of opinion by weighing or measuring them. Differences of opinion about interpreting experiments can be settled by running new experiments.

This methodical confirmation by independent observers is one of the major characteristics of science. The only experimental results that are accepted are those which can be confirmed by independent researchers repeating the experiments. The only arguments that are accepted are those which are lucidly presented to others for criticism. The personal authority of dead or living scientists is never a valid argument for accepting a hypothesis.

In this sense science is essentially egalitarian: no one has any special status as a source of knowledge. It is not by chance that science flourishes in open and democratic societies or that it is stunted in more authoritarian regimes. Democracy and science have common roots in the egalitarian, antiauthoritarian tradition of the Enlightenment. To me personally the ethical reasons for supporting them are very much the same.

Given this background it also seems natural to me to consider the ability to reach a consensus as the defining characteristic of science. For the purposes of this article, we will define science as follows: Science is the systematic search for knowledge which, not depending on any particular individual, can be established or controlled by anyone. Like most short definitions of complex concepts, this definition demands qualification and elaboration. There are, for example, individual differences in perception and communication. But rather than elaborate on these themes here, I will propose seven criteria for distinguishing science from pseudoscience.

Essentially, these criteria are seven different, though partially overlapping, ways of violating the above definition of science. Every instance of pseudoscience that I have encountered violates at least one of these seven criteria.

One: Personal Authority. The first criterion is that certain people are credited with such great ability to distinguish true and false that others should accept their verdicts. Such authoritarianism is common particularly in cultist pseudoscience. In most cases, these “authorities” are men.

One of the most extreme examples of this is the way Scientologists regard L. Ron Hubbard. For a Scientologist to question Hubbard’s words is practically equivalent to leaving the movement.

Other examples of personal authority are Maharishi Mahesh Yogi in Transcendental Meditation, Guru Maharaj Ji in the Divine Light Mission, and Rudolf Steiner in Anthroposophy. Their followers believe these men speak unarguable truth, whether or not these authorities can present arguments to support their contentions.

Two: Lack of Repeatability. The second criterion is that unrepeatable experiments are trusted. Since scientific knowledge is divorced from individual perception, experiments must be repeatable by other experimenters. Scientists also demand that experiments be reported in full, that is, in detail adequate for others to be able to duplicate the experimental conditions.

This principle is the same as that which applies to cooking. If I give you a recipe for muffins, and you follow the instructions but wind up taking floury lumps of dough out of the oven, you would probably feel dissatisfied if I told you, “Well, it worked last time I tried it, and that proves it works,” or “It’s your mental attitude—your negative vibrations destroy the muffins even if you do exactly what I do.”

But explanations like these are very common in pseudoscientific literature. Swedish engineer Olof Alexandersson provides one example of this in his book The Living Water when he claims that the Austrian eccentric Viktor Schauberger succeeded in constructing a perpetual motion machine in the 1930’s. According to Alexandersson, Schauberger made a working model of an airplane engine that needed no external energy sources. The fact that no one has been able to repeat the experiment does not seem to disturb Alexandersson. In another example, Cleve Backster “proved” with a lie detector that plants have feelings, but no one has since been able to duplicate his results.

Similar examples abound in the field of parapsychology, where there is a seemingly unending stream of experiments which yield positive results only in the hands of certain experimenters. This is in sharp contrast to studies of normal sensory phenomena carried out by experimental psychologists. Even subtle visual and auditory illusions can be verified by any experimenter who follows the appropriate procedures. Given the evidence we now have, therefore, from a scientific point of view we should accept these phenomena, though not the alleged paranormal ones.

Three: Biased Selection of Examples. The third criterion is that experiments are carried out on handpicked examples, even though random selection is possible. It is a common problem in scientific research that we want to study the characteristics of all objects or phenomena of a certain kind, but are limited to studying only a selection. How we make that selection is vital: if it is not random, the selection will reflect the personal choice of the investigator (experimenter bias). In the pursuit of consensus, random selection is essential.

This fallacy is, for example, common to most authors who have sought to prove the validity of biorhythms. It is easy to find plenty of individual examples which, taken together, seem to confirm the special significances of every 23rd, 28th, and 33rd day after birth. But applying this method of selection to different length cycles, it would be just as easy to prove that every 24th, 41st, and 53rd day after birth is exceptional—or any other days you like.

Similar reasons mean that even those fringe practitioners who use completely ineffective methods of treatment can point to an impressive number of “successfully treated” cases. Taken together, normal biological variation and wishful thinking are enough to convince any therapist—

medically trained or otherwise—that his chosen treatment works. This effect can only be avoided by giving randomly selected groups different treatments.

The essential characteristic of scientific medicine, then, is that medicine only resorts to judging by experience when controlled studies are not available. Most fringe practitioners are happy to regard their “successful cases” as proof enough that their treatments work.

Four: Lack of Reality Testing. The fourth criterion is that although it is perfectly possible, no attempt is made to test the theory against our own sensory experiences (or, for the philosophical realist, against reality). If you evade attempts to refute of confirm a theory by such methods, you make the theory a matter of personal faith. In contrast, the public process of critical debate and decisive experimentation is a prerequisite of science.

One example of this is the apparent unwillingness of TM proponents to allow independent observers to test their claim to be able to levitate. A Danish ex-TM-teacher who left the movement has revealed that the photographs of levitating TMers which the movement uses to publicize their activities are fakes produced with the help of gymnastics equipment. Since TM teaches levitation techniques on a regular basis, one would think that there would be no lack of subjects available to demonstrate these techniques. But TM representatives have been less than helpful, to say the least, to independent researchers interested in studying their methods.

Five: Contradictory Evidence Ignored. The fifth criterion is that proponents claim their theory is valid even though it contradicts reliable, empirical evidence. Some of the most commercially successful pseudoscientific writers provide us with numerous examples of this principle. Charles Berlitz’s Bermuda Triangle theory, for example, has been conscientiously examined by Larry Kusche, who showed it to be based entirely on misinformation. Erich von Daniken’s books, too, abound in statements which are demonstrably false. Neither Berlitz nor von Daniken has altered his theory in the light of factual criticism.

The science shelves of many bookshops are dominated by unreliable literature like that promulgated by Berlitz and von Daniken. This is sad but not surprising in the light of the different approaches taken to publication by scientists and pseudoscientists. Scientists, who submit their theories to the process of peer review for acceptance, generally publish their work in reputable journals and monograph series, which are generally unavailable to the public. These prestigious journals demand accuracy and revision in the light of new evidence, and are therefore closed to the pseudoscientists. These flock instead to the general book market, where what counts is a book’s appeal to the general public. Here they rely on sensationalism, rather than accuracy, to guarantee their books’ success.

Six: Refutation Not Accepted. The sixth criterion is that experimental results are accepted as confirmation—but not as refutation, so that testing the theory becomes a matter of ‘either I win or it was not conclusive.’ To take a simple example of this kind of thinking, let us suppose that I have proposed a theory that zinc accelerates the growth of roses. Let us also suppose that you have decided to test this theory with one hundred plants divided into two groups of 50: one with zinc added to the soil, one without.

If the plants in the zinc-impregnated soil grow faster, I would certainly say this confirmed my theory. You would probably accept that. However if the zinc-fed plants grew less than or the same amount as the others, you would probably expect me to accept that as evidence contradicting my theory. You would probably also think it unfair of me if I allowed only one of the possible results to affect my appraisal of my theory. Demanding that a theory be tested only under conditions that exclude negative results is another way of protecting oneself from others’ arguments; it is precisely these arguments that one must face in the search for consensus knowledge.

This type of built-in subterfuge is visible in many of the most common pseudoscientific theories. If an astrologer’s prophecies come true, a new triumph for horoscope-casting is proclaimed. If the prophecy fails, astrologers explain it away by saying that the stars only give “tendencies” and never tell us what the future will be. If water is found where a dowser recommended sinking a well, this is taken as proof of his powers. If no water is found there, you just didn’t dig deep enough. If a patient recovers after he has been treated by a faith-healer, the healer claims this is new proof of his particular relationship with the Highest. If the patient dies through lack of medical care, countless explanations can be found, all of which have in common that those who promise miracles are blameless.

Seven: Lack of Replacement. The seventh criterion is that the theory displaces other tenable theories while offering no replacement for them. This means that we lose some ability to describe accurately and predict phenomena; this is at direct variance with our common striving to enlarge our body of knowledge.

Immanuel Velikovsky’s celestial speculations are a good example of this principle. Carl Sagan has thoroughly demonstrated that his theory is incompatible with fundamental physical theories. But Velikovsky offers us no alternatives to the mechanics with which his theories conflict. Acceptance of his theories therefore means renouncing the coherent description we have of such diverse phenomena as the movements of celestial bodies and the centrifugal force we use in washing machines. This is a high price to pay for a theory whose only contribution to our ability to explain the world we live in is a shaky allegation of common sources for ancient narratives.

To cite another example, one of the tenets of Scientology is that your personality has been vitally affected by words uttered in your presence when you were still in embryo, even during the very first weeks after conception. Accepting this theory makes it necessary for us to relinquish our present explanations of the mechanism of hearing (namely, that we hear with our ears, which are not yet developed at this stage), of memory (that it is located in the brain, also not yet developed), and of the acquisition of language (that it takes place after birth). We gain nothing by the exchange, for Scientology explains no human behaviour for which we do not already have an explanation through conventional biology and psychology. Similarly, if we replace evolutionary theory with creationism, we lose the coherent biological and geological knowledge we have gained from the former and find ourselves facing a disconnected heap of facts.

I have endeavored to construct these seven criteria so that only clear cases of pseudoscience are rejected. Still it may be reasonable to ask: is there a risk that, using these criteria, we may dismiss new knowledge or new theories that we ought instead to accept?

My answer to this question is that we do not risk discarding true and well-founded assertions by using these criteria. Naturally, there is no guarantee that we would not fail to accept some true statements if they are insufficiently or fallaciously supported. Such cases will only come to light later when adequate evidence becomes available. At that time they, too, can be accepted.

I began by defining science as a process. It is the nature of Science to be an unending quest, just as it is the nature of Art never to be perfect. Seeking to understand the world we live in, searching for better knowledge; these are part of human nature. Science—rather than feeble imitations of it—should be available to everyone.

Sven Ove Hansson is a philosopher and author of a number of books, including two skeptical books on the paranormal. The English translation is by Sven Ove Hansson and Wendy M. Grossman, who together have also translated his 1986 book, Mysteries—Explained.