Pseudoscience

Phrenology is regarded today as a classic example of pseudoscience

The term pseudoscience which combines the Greek pseudo (false), and the Latin scientia (knowledge), appears to have been used first in 1843 by Magendie, who referred to phrenology as "a pseudo-science of the present day" Among its early uses was in 1844 in the Northern Journal of Medicine to describe "That opposite kind of innovation which pronounces what has been recognized as a branch of science, to have been a pseudo-science, composed merely of so-called facts, connected together by misapprehensions under the disguise of principles".

Introduction

What makes a body of knowledge, methodology, or practice "scientific" might seem to vary from field to field, but usually such judgements rest on to what extent "evidence" from "experiments" is important, and how evidence changes the nature of the current theories. If evidence is important, then it is important that it is reliable and reproducible, and so scientists take care to describe their methods precisely, and include "control experiments" to check that their interpretation is accurate. Things that we believe are true regardless of any evidence are not scientific truths; these things we might sometimes call dogma, or faith, or superstition. Things that we believe because of the evidence of our senses are not scientific truths either, these are merely facts, or deductions from facts. "If it walks like a duck and talks like a duck, it's a duck" is not a scientific statement, and it's no more scientific if we make it seem more profound, "If its gait is like that of Anatidae, and it vocalises like Anatidae...". However, "If it walks like a duck and talks like a duck, it has the genes of a duck" is a scientific statement, because it seeks to tell us much more than we can see for ourselves; it might be wrong, but it expresses a theory that what makes species distinctive is encoded in genes that are, in some ways, distinctive to that species. It's a bold speculation, but not a random one, as it's embedded in a large body of theoretical understanding about how bodies are built, about natural selection, and about molecular biology. It might still be wrong, but it is not trivial and it can be tested.

Science has acquired its authority from its successes in changing the world we live in, so when that authority is claimed without being earned, other scientists tend to get upset. When language is used that apes that of conventional scientists but without respect for its meaning, when claims are built on disputed dogma, when inconvenient evidence is ignored, or when grandiose theories are proposed that yield no non-trivial predictions and which seem incapable of proper test, then sometimes these things are called "pseudoscience"

However, there is disagreement about whether "science" can be distinguished from "pseudoscience" in any reliable and objective way, and about whether even trying to do so is useful. The philosopher of science Paul Feyerabend argued that all attempts to distinguish science from non-science are flawed. "The idea that science can, and should, be run according to fixed and universal rules, is both unrealistic and pernicious. ... the idea is detrimental to science, for it neglects the complex physical and historical conditions which influence scientific change. It makes our science less adaptable and more dogmatic:"  Often the term "pseudoscience" is used simply as a pejorative to express a low opinion of a given field, regardless of any objective measures; thus according to McNally, "The term “pseudoscience” has become little more than an inflammatory buzzword for quickly dismissing one’s opponents in media sound-bites." . Similarly, Larry Laudan has suggested that pseudoscience has no scientific meaning: "If we would stand up and be counted on the side of reason, we ought to drop terms like ‘pseudo-science’ and ‘unscientific’ from our vocabulary; they are just hollow phrases which do only emotive work for us".

Defining science by the scientific method

I feel that what distinguishes the natural scientist from laymen is that we scientists have the most elaborate critical apparatus for testing ideas: we need not persist in error if we are determined not to do so (Peter Medawar, "The Philosophy of Karl Popper" 1977)

In the mid-20th Century, Karl Popper published "The Logic of Scientific Discovery," a book that Sir Peter Medawar, a Nobel Laureate in Physiology and Medicine, called "one of the most important documents of the twentieth century". Popper explained that science does not advance because we learn more and more facts, but because the theories that it develops that make greater sense of the world, and in so doing it finds new and ever deeper questions to ask. Theories are the important feature of science, but theories can never be regarded as "true", they are always accepted, for the moment as useful, to be replaced in due course by a new and different theory. Popper analysed why theories are so important, how they are chosen, and how eventually they are discarded. Scientists do not start with facts and then somehow assemble them to provide a theory; any attempt to do so would be logically unsound because many different theories or explanations might be consistent with any known facts. "Out of uninterpreted sense-experiences science cannot be distilled, no matter how industriously we sort them". Instead, scientists interpret nature through "Bold ideas, unjustified anticipations, and speculative thought", The true scientist thus proposes an idea, as bold and exciting as he can, and then, instead of seeking evidence in favour of his idea - he tries as hard as he can to disprove it. For Popper, it is ideas that withstand determined attacks upon them that are valuable and important, and so the "content" of a theory can be gauged by the opportunities that it offers for experimental testing. If our ideas are worth anything, they will withstand the tests and challenges that they are exposed to; conversely, "those who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game".

For Popper therefore, a "pseudoscience" was a theory with superficial resemblence to science, but which was wholly empty, in being incapabable of disproof. He argued that astrology, Marxism, and Freudian psychoanalysis were all, essentially in the same way, empty theories because they allowed no possibility of disproof by experimental tests. Theories that cannot be falsified, he argued, have no connection with the real world.

Defining pseudoscience

Suppose Galileo were here and we were to show him the world today and try to make him happy, or see what he finds out. And we would tell him about the questions of evidence, those methods of judging things which he developed. And we would point out that we are still in exactly the same tradition, we follow it exactly — even to the details of making numerical measurements and using those as one of the better tools, in the physics at least. And that the sciences have developed in a very good way directly and continuously from his original ideas, in the same spirit he developed. And as a result there are no more witches and ghosts. (Richard Feynman)

Popper's vision of the scientific method was soon itself tested by Thomas Kuhn. Kuhn concluded, from studying the history of science, that science does not progress by linearly, but undergoes periodic revolutions, which he called "paradigm shifts", in which the nature of scientific inquiry in a particular field is abruptly transformed. He argued that falsification had played little part in such scientific "revolutions", and concluded that this was because rival paradigms are incommensurable - that it is not possible to understand one paradigm through the conceptual framework and terminology of another.

For Kuhn, whatever we mean by scientific progress, we must account for it by examining how scientists behave, and in particular by discovering what they value, what they tolerate, and what they disdain. What they value most of all, according to Kuhn, is the respect of their peers, and they normally achieve this by success in solving difficult "puzzles", while working with shared rules, a shared theoretical understanding, and towards shared objectives.

Such a closed group imposes its own expectations of rigor, and will tend to disparage claims that are, by those standards, vague, exaggerated or untestable. It would be normal for a group to expect that any claims are subject to "peer review" by the group before publication and acceptance, and that any claims are accompanied by enough detail to enable them to be verified and if possible, reproduced. Some proponents of theories that contradict accepted scientific theories avoid the often ego-bruising process of peer review, sometimes on the grounds that peer review is biased against claims that contradict established paradigms, and sometimes on the grounds that assertions cannot be evaluated using standard scientific methods.

It would be normal to expect appropriate "operational definitions" (i.e. rigorous descriptions of how measurements are made). However, for example, although most terms in theoretical physics have some connections with observables, they are not of the simple sort that would enable their use as operational definitions. "If a restriction in favor of operational definitions were to be followed, therefore, most of theoretical physics would have to be dismissed as meaningless pseudoscience!" Selective use of experimental evidence: presenting data that seem to support claims while suppressing or dismissing data that contradict them.

• Use of obscurantist language, and misuse of apparently technical jargon, in an effort to give claims the superficial trappings of science.

• Failure to use the principle of parsimony, i.e. failing to seek an explanation that requires the fewest possible additional assumptions when other viable explanations are possible (Occam's Razor)

• Lack of boundary conditions. Most well-supported scientific theories have clearly specified boundaries under which predictions do or do not apply.
• Assertion of claims that are unfalsififiable, i.e. which cannot be refuted by any conceivable experimental or observational test

Over-reliance on testimonials and anecdotes. Testimonial and anecdotal evidence can be useful for discovery (hypothesis generation) but should not be used in the context of justification (hypothesis testing). Reversed burden of proof. In science, the burden of proof rests on the individual making a claim, not on the critic. Personalization of issues Authoritarian personality, suppression of dissent, and "groupthink" can enhance the adoption of beliefs that have no rational basis. The group tends to identify their critics as enemies.

Assertion of claims of a conspiracy by the scientific community to suppress the results.  Attacking the motives or character of anyone who questions the claims (Ad hominem fallacy).

The demarcation problem, and criticisms of the concept of pseudoscience

Nothing is more curious than the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of its existing modes of knowledge. (Alfred North Whitehead)

Despite broad agreement on the basics of the scientific method, the boundaries between science and non-science continue to be debated. This is the problem of demarcation. The defining feature of science is not experimental success, for, in Rothbart's words, "most clear cases of genuine science have been experimentally falsified". Many disciplines currently thought of as science exhibited at some time in their history, features which are often cited as flaws of scientific method, and many currently accepted scientific theories — including the theory of evolution, plate tectonics, the Big Bang (a term originally chosen by Fred Hoyle to poke fun at the idea), and quantum mechanics — were criticized as being pseudo-scientific when first proposed. In retrospect, it is clear that this was a response to the challenges that they posed to accepted doctrines, and a reflection of the difficulty in gathering evidence for new theories. Further, because of the heterogeneous nature of the scientific enterprise itself, it is difficult to create a set of criteria which can be applied to all disciplines at all times.

Lessons from the History of Science

Science is as sorry as you are that this year's science is no more like last year's science than last year's was like the science of twenty years gone by. But science cannot help it. Science is full of change. Science is progressive and eternal. The scientists of twenty years ago laughed at the ignorant men who had groped in the intellectual darkness of twenty years before. We derive pleasure from laughing at them. (Mark Twain, "A Brace of Brief Lectures on Science", 1871)

Imre Lakatos proposed that it might instead be possible to distinguish between "progressive" and "degenerative" research programs . Kuhn questioned this, asking "Does a field make progress beecause it is a science, or is it a science because it makes progress?" He also questioned whether scientific revolutions were obviously progressive, noting that Einstein's general theory of relativity is in some respects closer to Aristotle's than either is to Newton's.

Lack of progress Thagard proposed that a theory or discipline which has pretensions to be scientific can be regarded as pseudoscientific if (and only if): "it has been less progressive than alternative theories over a long period of time, and faces many unsolved problems; but the community of practitioners makes little attempt to develop the theory towards solutions of the problems, shows no concern for attempts to evaluate the theory in relation to others, and is selective in considering confirmations and disconfirmations"

The term "pseudoscientific" is sometimes applied by one scientist to disparage a competing theory or the argument of a rival, sometimes by commentators from outside a field to disparage a whole field, sometimes to express the opinion that a theory published in a popular book has no academic credibility, and sometimes in reference to a theory now discarded. However, for many, at least some "pseudoscientific" beliefs are harmless nonsense; horoscopes are read for fun by many, but taken seriously by few. The National Science Foundation stated that, in the USA, "pseudoscientific" habits and beliefs are common in the USA. Bunge (1999) stated that a 1988 survey showed that 50% of American adults rejected evolution, and 88% believed that astrology was a science. The brights movement, prominently represented by Richard Dawkins, Mario Bunge, Carl Sagan and James Randi, consider that while pseudoscientific beliefs may be held for several reasons, from simple naïveté about the nature of science, to deception for financial or political gain, all such beliefs are harmful.