- 1 Introduction
- 2 How pseudoscience flourishes
- 3 Paradigmatic examples
- 4 Pseudoscience and the philosophy of science
- 5 Notes
A pseudoscience is any theory, or system of theories, that is claimed to be scientific by its proponents but that the scientific community deems flawed, usually because independent attempts at reproducing evidence for specific claims made on the basis of these theories have failed repeatedly and rarely if ever succeeded. The term is pejorative, and its use is inevitably controversial; the term is also problematical because of the difficulty in defining rigorously what science is. Some ideas (like phrenology) were once considered respectable sciences, but were later dismissed as pseudoscience. There are some areas today, such as psychoanalysis, about which there is a serious dispute as to whether they may properly be considered pseudoscience.
The term "pseudoscience", which combines the Greek root pseudo, meaning "false", and the Latin scientia, meaning "knowledge", seems to have been used first in 1843 by the French physiologist François Magendie (1783–1855), who referred to phrenology as "a pseudo-science of the present day". Among its early uses was one in 1844 in the Northern Journal of Medicine, I 387: "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".
Casting horoscopes based on the night sky has been used to predict the future for at least two thousand years, long before the establishment of the scientific method. Although many contemporary astrologers continue in this mystical tradition, some of them argue that their methods are scientific - a view that opens them to the charge of pseudoscience. Astrology is generally regarded as nonsense by scientists, but sometimes it can be hard to tell the difference between an idea that is plausible but not generally accepted and one that is simply unsound.
Generally, pseudoscientific claims either (1) lack supporting evidence, or (2) are based on evidence that is not established by scientific methods or (3) cite well-established evidence but misuse it or misinterpret it to support the conclusions asserted in the claim. Science has considerable prestige in modern societies; often, to call something "scientific" is to suggest that it is true. Conversely, theories that do not follow the methods of science are likely to be dismissed not only as "unscientific" or "pseudoscientific", but also as fallacious.
For those whose sincerely held theories are dismissed as "pseudoscience," that label often cuts to the quick. The charge can imply poor training, inadequate education, faulty judgment, or outright fraud, and thereby prompts defensive outrage from its targets.
How pseudoscience flourishes
It is often wondered why so many people seem to be willing to believe some extraordinarily improbable things on the basis of the flimsiest of evidence.
Some nonsense is given credence because it validates particular religious or political beliefs. Creationism and intelligent design are both adopted primarily because they support certain religious – often Christian – beliefs. Moral and political thought also comes into it: many fear that an evolutionary view of the universe has negative moral consequences and so prefer any alternative theory.
Lies, fallacies, misrepresentations, distortions and other nonsense sometimes enter the public consciousness because of how the news media works. Newspapers have increased in size and there are now many more broadcast outlets than ever before – hundreds more channels on cable and satellite television, thousands of news blogs and websites. To fill this gap, reporters spend less time checking facts, and often simply report on press releases delivered to them by public relations agencies, including by some who commission studies to fit various corporate or political agendas. Many of these are novelty or fun pieces, others are fluffy pieces on shaky social science research, but some cover serious health and medical topics. Few science reporters have any training in science, and often seem woefully poor at telling the difference between good science and rubbish.
Pseudoscience is often promoted by reference to the "underdog" credentials of the proponents. Frequent mention is made of Galileo and others who were persecuted for ideas that later turned out to be correct. Carl Sagan commented on this:
"The fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown."
The "Gish Gallop" is an argument style used by the creationist Duane Gish where many claims are made in a short time during a formal, timed debate. It can take just a few seconds to make a claim, but much longer to refute it. When the respondent doesn't have enough time to address all of the claims, he appears to be leaving questions "still unanswered". Some prominent pseudoscientists are savvy media operators, while scientists become famous for their work in the lab, not their skills as public performers; the pseudoscientist can often be cast in the "everyman" role while the scientist is portrayed as an ivory-tower intellectual, an elitist or as somehow anti-democratic.
In the public debate over climate change, scientists are often portrayed as accepting conclusions regarding anthropogenic global warming because of the pressure to continue getting funding. This charge is promoted by climate change denial groups that are themselves massively funded by the oil industry.
The issue of conflict of interest is a serious one, as conflicts can cloud judgement, but to assign motives to any speaker is to avoid the issues under debate, and is a disreputable strategy whether used by scientists ("he would say that wouldn't he, because he's a homeopath") or by their critics ("he has to say that or he wouldn't get grants"). There have been some well-publicised cases of fraudulent science, but for most scientists, their careers ultimately depend on being right, and advantages gained through being parsimonious with the truth or selective with facts are likely to be short term - any important claim is likely to be quickly put to the test - and the reputational risk of being proved wrong is great.
"As the new Darwinian orthodox' swept through Europe, its most brilliant opponent, the aging embryologist Karl Ernst von Baer, remarked with bitter irony that every triumphant theory passes through three stages: first it is dismissed as untrue; then it is rejected as contrary to religion; finally, it is accepted as dogma and each scientist claims that he had long appreciated its truth.
I first met the theory of continental drift when it labored under the inquisition of stage two. Kenneth Caster, the only major American paleontologist who dared to support it openly, came to lecture at my alma mater, Antioch College. We were scarcely known as a bastion of entrenched conservatism, but most of us dismissed his thoughts as just this side of sane. ...
Today, just ten years later, my own students would dismiss with even more derision anyone who denied the evident truth of continental drift..."
Some theories, claims, and practices that, when new, were dismissed as pseudoscientific, have since become accepted. The theory of continental drift that led to the current theory of plate tectonics was first proposed by Alfred Wegener in 1910, but for many decades after Wegener's death it was largely dismissed as "eccentric, preposterous, and improbable". The Big Bang was a term originally chosen by Fred Hoyle to poke fun at the idea. They have since won general acceptance. In retrospect, the delay in acceptance of these and other revolutionary theories was clearly a result of the challenges that they posed to the accepted doctrines of the time, and of the difficulty in gathering evidence for new theories.
Astrology (not to be confused with astronomy) refers to 'fortune-telling' based on the position (relative to earth) of the sun, moon, stars, and/or constellations. Some astrologers claim scientific status for their discipline, or some aspects of it; the activity at least makes certain assumptions which ought to be subject to scientific testing.
However unlikely, it is not inconceivable that the movements of the moon or planets might have some influence on human activity or emotions. The major criticism of astrology is that there is no good evidence for its claims, and no rational, logical structure to its theories. It often functions essentially as a religious activity, impervious to research.
Astrological researchers often complain that they cannot receive a fair hearing in scientific circles, and find it hard to have their research published in scientific journals. They claim that their critics have wrongly dismissed studies that do support astrology. An example would be Michel Gauquelin's purported discovery of correlations between some planetary positions and certain human traits such as vocations. However, an examination of Gauquelin's claims by the Belgian Comiti Para and by the French Comité Français pour l'Étude des Phénomènes Paranormaux concluded that Gauquelin had selected results to support his conclusions.
Astrology can be dismissed as harmless nonsense. However, there are deeper concerns when ineffective health treatments are sold on the basis of pseudoscientific advertising – i.e. when advocates couch their claims in terms that make them falsely appear to have a credible scientific foundation. Patients with serious diseases may be deflected from seeking effective medical treatment by the false hopes engendered by remedies falsely promoted as being scientifically well-founded. Homeopathic remedies are safe in the sense that they contain no active ingredients and hence have no verified activity beyond that of placebos; but some homeopaths advise that their remedies are a suitable alternative to vaccinations, and such advice is considered dangerously irresponsible by public health professionals. Claims for herbal remedies, multi-vitamin supplements and other dietary supplements are also causes for concern: these products are extensively promoted, widely available and poorly regulated. While some supplements can be beneficial for some people, for many there is no benefit and for some there can be adverse consequences.
In general, though, the principal concern about false health claims is not that they are pseudoscientific, but simply that they are false. Some alternative medicine systems are also attacked by scientists for two main reasons: when they fail the practical test of clinical efficacy or refuse to submit to such study, and when they posit mechanisms for the supposed success of their treatment methodologies that rely on outdated notions that do not fit with modern scientific understanding.
Scientists have a natural interest in defending the good name of science by exposing and debunking bad science wherever it is manifested, but medics have a different concern: to expose and discredit ineffective treatments simply because they are ineffective. Some ineffective treatments are promoted using pseudoscientific claims, others appeal to religious or spiritual rationales and don’t pretend a scientific basis, and yet others have a misguided scientific basis. In the end, if an argument is nonsense, or a claim false, the issue of whether it has also wrongly invoked the authority of science is incidental.
Cognitive scientists do not agree on what, if anything, intelligence is, let alone how to test for it. Nevertheless one particular measure—scores from a range of standardized Intelligence Quotient (IQ) tests—is widely used. Originally designed for educational and military use, the Stanford-Binet Intelligence Scale and its offshoots measure several cognitive capabilities such as language fluency, or three-dimensional thinking. While these may seem unrelated, test scores do in fact tend to correlate. The premise of IQ tests is that such capabilities all depend on some underlying factor, called the general intelligence factor. To critics, the concept smacks of metaphysics. Does "IQ" in fact measure anything at all? Subsidiary questions relating to intelligence and IQ involve the relative importance of nature vs. nurture, and the distribution of IQ between men and women, and among the various races (cf. intelligence and race). Accusations of pseudoscience are not difficult to find in these discussions.
Freud's proposal that mental illness might be treated through talk rather than surgery, drugs, or hypnosis was only one of the startling features of psychoanalysis contrasting it to earlier conceptions of psychiatry. The concept remains controversial today. Does psychotherapy "work"? Is it any more effective than ordinary talk? (Effective at what?)
Critics also wonder what ontological status is being claimed for various abstract entities in psychological theory, such as Freud's ego and id, which would seem unavailable for scientific inspection. In what way do psychoanalysis and its successors differ from religions? The question is even more sensitive in the case of Jungian psychology and transpersonal psychology, which are more interested in the spiritual dimension.
In The Myth of Mental Illness and other works, Thomas Szasz proposed that the entire concept of 'mental illness' is a tool of social control at the hands of a 'pharmacracy'. In his view, a disease must be something concrete and measurable, not an abstract condition which comes into existence by vote. In this light, current attitudes toward mental illness are no more rational than 19th-century campaigns against onanism.
Intelligent design, as promoted by the Discovery Institute, argues that the complexity and harmony of the universe and of life on earth implies the existence of an intelligent creator. To its critics, the theory was designed to circumvent U.S. prohibitions against the teaching of creation science as part of the scientific curricula of public schools. If so, the strategy did not work. In his decision for Kitzmiller v. Dover Area School District, Judge John E. Jones III agreed that intelligent design is "a mere re-labeling of creationism, and not a scientific theory". He went on to say (p.64):
We find that ID fails on three different levels, any one of which is sufficient to preclude a determination that ID is science. They are: (1) ID violates the centuries-old ground rules of science by invoking and permitting supernatural causation; (2) the argument of irreducible complexity, central to ID, employs the same flawed and illogical contrived dualism that doomed creation science in the 1980's; and (3) ID's negative attacks on evolution have been refuted by the scientific community.
Cargo cult science
For many people, at least some 'pseudoscientific' beliefs, for example that the pyramids were built not by men but by prehistoric astronauts, are harmless nonsense. "Horoscopes" (not what professional astrologers mean by the term but what the general public means by it) are read for fun by many, but taken seriously by few. According to Scott Lillenfeld, popular psychology is rife with pseudoscientific claims: self-help books, supermarket tabloids, radio call-in shows, television infomercials and 'pseudodocumentaries', the Internet, and even the nightly news promote unsupported claims about, amongst other things, extrasensory perception, psychokinesis, satanic ritual abuse, polygraph testing, subliminal persuasion, out-of-body experiences, graphology, the Rorschach test, facilitated communication, herbal remedies for memory enhancement, the use of hypnosis for memory recovery, and multiple personality disorder. He suggests that critically interrogating these claims is a good way of introducing students of psychology to understanding the scientific method, bearing in mind Stephen Jay Gould's aphorism that "exposing a falsehood necessarily affirms a truth".
The Nobel Laureate Richard Feynman recognized the importance of unconventional approaches to science, but was bemused by the willingness of people to believe "so many wonderful things." He was however much more concerned about how ordinary people could be intimidated by experts propounding "science that isn't science" and "theories that don't work":
- There are big schools of reading methods and mathematics methods, and so forth, but if you notice, you'll see the reading scores keep going down ... And I think ordinary people with commonsense ideas are intimidated by this pseudoscience. A teacher who has some good idea of how to teach her children to read is forced by the school system to do it some other way — Or a parent ... feels guilty ... because she didn't do 'the right thing', according to the experts... Richard Feynman, Cargo Cult Science
For Feynmann, it came down to a certain type of integrity, a "kind of care not to fool yourself", that was missing in what he called "cargo cult science".
Pseudoscience and the philosophy of science
There is disagreement not only about whether 'science' can be distinguished from 'pseudoscience' objectively, but also about whether trying to do so is even useful. The philosopher Paul Feyerabend argued that all attempts to distinguish science from non-science are flawed. He argued that the idea that science can or should be run according to fixed rules is "unrealistic and pernicious... 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 field, regardless of any objective measures; thus according to McNally, it is "little more than an inflammatory buzzword for quickly dismissing one’s opponents in media sound-bites." Similarly, Larry Laudan 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 'pseudoscience' and ‘unscientific’ from our vocabulary; they are just hollow phrases which do only emotive work for us".
Skepticism is generally regarded as essential in science, but skepticism is properly defined as doubt, not denial. The sociologist Marcello Truzzi distinguished between 'skeptics' and 'scoffers' (or 'pseudo-skeptics'). Scientists who are scoffers fail to apply the same professional standards to their criticism of unconventional ideas that would be expected in their own fields; they are more interested in discrediting claims of the extraordinary than in disproving them, using poor scholarship, substandard science, ad hominem attacks and rhetorical tricks rather than solid falsification. Truzzi quotes the philosopher Mario Bunge as saying: "the occasional pressure to suppress [dissent] in the name of the orthodoxy of the day is even more injurious to science than all the forms of pseudoscience put together."
Because science is so diverse, it is hard to find rules to distinguish between what is scientific and what is not that can be applied consistently. Imre Lakatos suggested that we might however distinguish between 'progressive' and 'degenerative' research programs; between those which evolve, expanding our understanding, and those which stagnate. Paul Thagard proposed, more formally, that a theory can be regarded as pseudoscientific 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".
Thomas Kuhn saw a circularity in this, and questioned whether a field makes progress because it is a science, or whether is it a science because it makes progress. He also questioned whether scientific revolutions were in fact progressive, noting that Einstein's general theory of relativity is in some ways closer to Aristotle's than either is to Newton's. Most progress in science, according to Kuhn, is not at times of scientific revolution, when one theory is replacing another, but when one paradigm is dominant, and when scientists who share common goals and understanding fill in the details by puzzle solving. He argued that, when a theory is discarded, it is not always the case (at least not at first) that the new theory is better at explaining facts. Which of two theories is 'better' is largely a matter of opinion. The reasons for discarding a theory may be that more and more anomalies that reveal its weaknesses become apparent, but there is no point at which the followers of one theory abandon it in favor of a new one; instead, they cling tenaciously to the old theory, while seeking fresh explanations for the anomalies. A new theory takes over not by converting followers of the old theory, but because, over time, the new view gains more and more followers until it becomes dominant, while the older view is held in the end only by a few "elderly hold outs". Kuhn argued that such resistance is not unreasonable, or illogical, or wrong; instead he thought that the conservative nature of science is an essential part of what enables it to progress. At most, it might be said that the man who continues to resist the new view long after the rest of his profession has adopted a new view "has ipso facto ceased to be a scientist".
As Kuhn described them to be, the motives of the true scientist are to gain the respect and approval of his or her peers. When technical jargon is misused, or when scientific findings are represented misleadingly, to give particular claims the superficial trappings of science for some commercial or political gain, this is easily recognized as an abuse of science; it is not an abuse that is confined to popular literature, however.
Despite the complexity of the issue, solutions to the problem of demarcation were proposed in the 20th century that can be collected into two main lines of thinking (see also scientific method, Karl Popper and Thomas Kuhn for further discussion).
Defining science by the falsifiability of theories
Karl Popper described science as an "objective product of human thought", as much as a nest can be seen as an objective product of a bird. Consequently, he dismissed as insignificant the philosophical tendency to regard knowledge as subjective, which includes the definition of science by the behavior of scientists as described above.
Popper's solution to the demarcation problem is given in his 1934 book 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 suggested that science does not advance because we learn more and more facts. Science does not start with observations and then somehow assemble them to provide a theory; any attempt to do so would be logically unsound, because a general theory contains more information than any finite number of observations. Popper shows this with a simple example. Let's say we have seen millions of white swans. We may be tempted to conclude, by the process called induction, that "All swans are white". But however many white swans we have seen, the next swan we see might be black.
Rather, the advance of science consists of three steps: (1) we find a problem; (2) we try to solve the problem by a new theory; (3) we critically test our theory and, while doing this, we learn from our errors. It is in the process of critical testing of theories that Popper finds the distinguishing characteristics of science.
For Popper, there is no way a scientific theory can be proven to be true; a theory comes to be accepted because it has survived all attempts to disprove it, but it is only accepted provisionally, until something better comes along. This may be explained again with the example of swans. How could we ever prove the truth of our theory that "all swans are white"? Only by observing all swans of the universe in all past, present and future times, and showing they are all white. This is, of course, impossible. Yet, an assertion such as our "all swans are white" is a scientific statement (although a false one).
Following Popper, scientific theories must include falsifiable universal assertions, i.e., general statements that cannot be proven true, but can eventually be found false when a new observation, e.g., of a black swan, disproves them. Assertions that are not falsifiable are non-scientific, and the refusal to critically discuss a theory is a non-scientific attitude as well. As Popper puts it, "those who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game".
Accordingly, a 'pseudoscience' is a system of assertions with a superficial resemblance to science, but which is empty, in being in principle incapable of disproof. Scholars that refuse to engage in a critical discussion of their doctrine exhibit a 'pseudoscientific' attitude.
Popper argued that astrology, Marxism, and Freudian psychoanalysis are all 'pseudoscientific' because they make no predictions by which their truth can be judged; accordingly they cannot be falsified by experimental tests, and have thus no connection with the real world.
Defining science by the behavior of scientists
Popper's vision of the scientific method was itself tested by Thomas Kuhn. Kuhn concluded, from studying the history of science, that science does not progress linearly, but undergoes periodic 'revolutions', in which the nature of scientific inquiry in a field is transformed. He argued that falsification had played little part in such revolutions, because rival world views are incommensurable - he argued that it is impossible to understand one paradigm through the concepts and terminology of another.
For Kuhn, to account for scientific progress, we must examine how scientists behave, and observe what they value, what they tolerate, and what they disdain. He concluded that they value most the respect of their peers, and they gain this by solving difficult 'puzzles', while working with shared rules towards shared objectives. Kuhn maintained that typical scientists are not objective, independent thinkers, but are conservatives who largely accept what they were taught. Most aim to discover what they already know - "The man who is striving to solve a problem ... knows what he wants to achieve, and he designs his instruments and directs his thoughts accordingly."
Such a closed group imposes its own expectations of rigor, and disparages claims that are (by their conventions) vague, exaggerated, or untestable. Within any field of science, scientists develop a technical language of their own; to a lay reader, their papers may seem full of jargon, pedantry, and obscurantism. What seems to be bad writing is often just bad writing, but sometimes reflects an obsession with using words precisely. Scientists also expect any claims to be subject to peer review before publication and acceptance, and demand that any claims are accompanied by enough detail to enable them to be verified and, if possible, reproduced. Some proponents of unconventional 'alternative' theories avoid this often ego-bruising process, sometimes arguing that peer review is biased in favor of conventional views, or that assertions that lie outside what is conventionally accepted cannot be evaluated fairly using methods designed for a conventional paradigm.
Popper saw dangers in the closed worlds of specialists, but while admitting that, at any one moment, we are 'prisoners caught in the framework of our theories', he denied that different frameworks are like mutually untranslatable languages; he argued that clashes between frameworks have stimulated some of the greatest intellectual advances. Popper recognised what Kuhn called 'normal science', but for him, that was the activity of "the not-too critical professional, of the science student who accepts the ruling dogma of the day;... who accepts a new revolutionary theory only if almost everybody else is ready to accept it." Popper acknowledged its existence, but saw it as the product of poor teaching, and also doubted whether 'normal' science was indeed normal. Whereas Kuhn had pictured science as progressing steadily during long periods of stability within a dominant paradigm, punctuated occasionally by scientific revolutions, Popper thought that there was always a struggle between sometimes several competing theories.
Popper's analysis was prescriptive; he described what he thought scientists ought to do, and claimed that this is what the best scientists did. Kuhn, by contrast, claimed to be describing what scientists in fact did, not what he thought they ought to do, but nevertheless he argued that it was rational to attribute the success of science to the scientists' behavior. Whereas Popper was scathing about the conservative scientist who accepted the dogma of the day, Kuhn proposed that such conservatism might be important for progress. According to Kuhn, scientists do not normally try to overthrow theories, but rather they try to bring them into closer agreement with observed facts and other areas of understanding. Accordingly, they tend to ignore research findings that threaten the existing paradigm; "novelty emerges only with difficulty, manifested by resistance, against a background provided by expectation".
Yet there are controversies in every area of science, and they lead to continuing change and development. Scientists are scornful of the selective use of experimental evidence - presenting data that seem to support claims while suppressing or dismissing data that contradict them - and peer-reviewed journals generally insist that published papers cite others in a balanced way. Imre Lakatos attempted to accommodate this in what he called 'sophisticated falsification', arguing that it is only a succession of theories and not one given theory which can be appraised as scientific or pseudoscientific. A series of theories usually has a continuity that welds them into a research program; the program has a 'hard core' surrounded by "auxiliary hypotheses" which bear most tests, but which can be modified or replaced without threatening the core understanding.
- Still A, Dryden W (2004)The Social Psychology of "Pseudoscience": A Brief History J Theory Social Behav 34:267-90 ("The word has asserted the scientific credentials of the user at the same time as it denies these credentials to the pseudoscientist.")
- From Broca's Brain: Reflections on the Romance of Science by Carl Sagan (1986) ISBN-10: 0345336895. Perhaps they were right to laugh at Columbus; his plan to reach the East by sailing West was founded on the mistaken beliefs that the Asian continent stretched much farther to the east than it actually does and that Japan lay about 2,400 km east of the Asian mainland; he also greatly underestimated the circumference of the earth.
- ExxonMobil continuing to fund climate sceptic groups Guardian 1 July 2009
- Oil conglomerate 'secretly funds climate change deniers' Telegraph 25 Nov 2010
- "The Validation of Continental Drift" - Stephen Jay Gould
- Developing the theory USGS)
- see a BBC article on Big Bang 
- Kurtz P et al. (1997) Is the "Mars Effect" genuine? J Scientific Exploration 11:19-39
- Multivitamin prostate warning ‘’BBC News’’ 16 May 2007 [ http://news.bbc.co.uk/1/hi/health/6657795.stm]
- Multivitamin supplements a 'waste of time' ‘’The Independent’’ 10 February 2009 
- The rise and fall of IQ Vanessa Thorpe and Robin McKie, Sunday 17 March 2002, The Observer
- Graves JL, Johnson A (1995) The Pseudoscience of Psychometry and The Bell Curve Journal of Negro Education 64:277-294 
- Lilienfeld SO (2004) Teaching Psychology Students to Distinguish Science from Pseudoscience: Pitfalls and Rewards
- The National Science Foundation stated that 'pseudoscientific' habits and beliefs are common in the USA
- National Science Board (2006) Science and Engineering Indicators 2006 Two volumes. Arlington, VA: National Science Foundation (volume 1, NSB-06-01; NSB 06-01A)
- Criticisms of the concept of pseudoscience
- Paul Feyerabend (1975) 'Against Method: Outline of an Anarchistic Theory of Knowledge' 
- McNally RJ (2003)Is the pseudoscience concept useful for clinical psychology? SRHMP'' Vol 2 Number 2
- Laudan L (1996) The demise of the demarcation problem, in Ruse M 'But Is It Science?: The Philosophical Question in the Creation/Evolution Controversy' pp 337-50
- John Stuart Mill On Liberty (1869) Chapter II: Of the Liberty of Thought and Discussion
- Marcello Truzzi On Some Unfair Practices towards Claims of the Paranormal; On Pseudo-Skepticism
- The progress of science
- Hawking SW (1993) 'Hawking on the Big Bang and Black Holes' World Scientific Publishing Company, Page 1,  and .
- Currently, string theory has been criticized by some researchers, e.g. Smolin L (2006) The Trouble with Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next Houghton Mifflin Company. ISBN 0618551050
- Lakatos I (1977) The Methodology of Scientific Research Programmes: Philosophical Papers Volume 1 Cambridge: Cambridge University PressScience and Pseudoscience - transcript and broadcast of talk by Imre Lakatos
- Thagard PR (1978) Why astrology is a pseudoscience In PSA Volume 1 ed PD Asquith and I Hacking (East Lansing: Philosophy of Science Association
- Popular pseudoscience
- :Tsai AC (2003) Conflicts between commercial and scientific interests in pharmaceutical advertising for medical journals. Int J Health Serv 33:751-68 PMID 14758858
- Cooper RJ et al. (2003) The quantity and quality of scientific graphs in pharmaceutical advertisements. J Gen Intern Med 18:294-7 PMID 12709097
- Karl R. Popper, 1967, Epistemology without a knowing subject, in: Massimo Baldini and Lorenzo Infantino, eds., 1997, Il gioco della scienza, Armando Editore, Roma (Italy), 158 pp. ISBN 88-7144-678-X
- Sir Karl Popper
- Popper KR (1959) The Logic of Scientific Discovery English translation;:Karl Popper Institute includes a complete bibliography 1925-1999
- Popper KR (1962) Science, Pseudo-Science, and Falsifiability
- Karl Popper from Stanford Encyclopedia of Philosophy
- Sir Karl Popper: Science: Conjectures and Refutations
- Kuhn TS (1962) 'The Structure of Scientific Revolutions' Chicago: University of Chicago Press, ISBN 0-226-45808-3
- Sometimes technical terms have strict definitions in terms of things that can be measured (operational definitions). Other terms 'stand for' things not yet understood in detail - even in theoretical physics for instance, although most terms have some connection with observables, they are seldom of the sort that would enable them to be used as operational definitions. As Churchland observed, "If a restriction in favor of operational definitions were to be followed ... most of theoretical physics would have to be dismissed as meaningless pseudoscience!" Churchland P Matter and Consciousness: A Contemporary Introduction to the Philosophy of Mind (1999) MIT Press [http://books.google.com/books?
- Peer review and the acceptance of new scientific ideas For an opposing perspective, e.g. Peer Review as Scholarly Conformity
- Lakatos I (1970) "Falsification and the Methodology of Scientific Research Programmes" in Lakatos I, Musgrave A (eds) Criticism and the Growth of Knowledge Cambridge University Press pp 91–195