The terms pseudoskepticism (sometimes pseudo-skepticism) and pathological skepticism are used to denote the phenomena when certain forms of skepticism deviate from objectivity. The term has been in limited use in philosophy for more than a century, but has only recently been the object of more systematic attempts at defining the concept. The most well known analysis of the term has been conducted by Marcello Truzzi, who in 1987 stated that:
- Since "skepticism" properly refers to doubt rather than denial — nonbelief rather than belief — critics who take the negative rather than an agnostic position but still call themselves "skeptics" are actually pseudo-skeptics.
Characteristics of pseudoskeptics
The first extensive analysis of the term pseudoskepticism was conducted by Marcello Truzzi, Professor of Sociology at Eastern Michigan University, who in 1987 claimed that pseudoskeptics show the following characteristics:
- The tendency to deny, rather than doubt,
- Double standards in the application of criticism, 
- The making of judgements without full inquiry,
- Tendency to discredit, rather than investigate,
- Use of ridicule or ad hominem attacks,
- Presenting insufficient evidence or proof, 
- Pejorative labelling of proponents as 'promoters', 'pseudoscientists' or practitioners of 'pathological science.' 
- Assuming criticism requires no burden of proof, 
- Making unsubstantiated counter-claims,
- Counter-claims based on plausibility rather than empirical evidence,
- Suggesting that unconvincing evidence is grounds for dismissing it,
- Tendency to dismiss all evidence, 
A Spring 2006 course at the University of Colorado, "Edges of Science" which "Examines the evidence for paranormal phenomena, [and] reasons for skepticism", includes a section which shows "how a healthy skepticism can see through unsupported assertions, and how pathological skepticism can work against honest scientific inquiry." 
The Laboratory for Advances in Consciousness and Health at the University of Arizona, run by Prof. Gary Schwartz, claims to provide "a responsible forum in which to conduct systematic research on pathological skepticism, illusory correlates, and self-deception in science, society, and human relationships." The lab's research into "the role of conscious intention in energy medicine and healing, and the possibility of survival of consciousness after physical death" has been criticized in The Skeptical Inquirer because it did not consider non-paranormal explainations for the observations recorded..
The term "pseudo-skepticism" appears to have its origins with 19th and early 20th century philosophy.
On 31 Aug 1869, Swiss philosopher Henri-Frédéric Amiel wrote in his diary:
- "My instinct is in harmony with the pessimism of Buddha and of Schopenhauer. It is a doubt which never leaves me, even in my moments of religious fervor. Nature is indeed for me a Maïa; and I look at her, as it were, with the eyes of an artist. My intelligence remains skeptical. What, then, do I believe in? I do not know. And what is it I hope for? It would be difficult to say. Folly! I believe in goodness, and I hope that good will prevail. Deep within this ironical and disappointed being of mine there is a child hidden — a frank, sad, simple creature, who believes in the ideal, in love, in holiness, and all heavenly superstitions. A whole millennium of idyls sleeps in my heart; I am a pseudo-skeptic, a pseudo-scoffer."
In 1908 Henry Louis Mencken wrote on Friedrich Nietzsche's criticism of philosopher David Strauss that:
- "Strauss had been a preacher but had renounced the cloth and set up shop as a critic of Christianity. He had labored with good intentions, no doubt, but the net result of all his smug agnosticism was that his disciplines were as self-satisfied, bigoted, and prejudiced in the garb of agnostics as they had been before Christians. Nietzsche's eye saw this and in the first of his little pamphlets "David Strauss, der Bekenner und der Schriftsteller" ("David Strauss, the Confessor and the Writer"), he bore down on Strauss's bourgeoise pseudo-skepticism most savagely. This was 1873".
Professor of Philosophy at the University of Illinois, Frederick L. Will used the term "pseudo-skepticism" in 1942. Alasdair MacIntyre writes:
- [Frederick] Will was no exception. He began as an analytical philosopher, distinguishing different uses of language with the aim of showing that certain traditional philosophical problems need no longer trouble us, once we have understood how to make the relevant linguistic distinctions. The enemies were two: the philosophical skeptic who poses these false problems and the philosopher who thinks that the skeptic needs to be answered. So in "Is there a Problem of Induction?" (Journal of Philosophy, 1942) it is two senses of "know" that are to be distinguished: "All the uneasiness, the pseudo-skepticism and the pseudo-problem of induction, would never appear if it were possible to keep clear that 'know' in the statement that we do not know statements about the future is employed in a very special sense, not at all its ordinary one".
Notre Dame Professor of English, John E. Sitter used the term in 1977 in a discussion of Alexander Pope: "Pope's intent, I believe, is to chasten the reader's skepticism — the pseudo-skepticism of the overly confident 'you' ... "
The term pseudoskepticism was popularised and characterised by Truzzi in 1987, in response to the skeptic groups who applied the label of "pseudoscientists" to fields which Truzzi thought might be better described as protoscience.
Science writer C. Eugene Emery, Jr. compared the degrees of skepticism of CD-ROM-based encyclopedias of articles on pseudoscientific subjects. He called such articles "pseudoskeptical" if only suggested or stated that the subject was "controversial, but the author may not have a clue as to why". 
- "Marcello Truzzi, On Pseudo-Skepticism" Zetetic Scholar (1987) No. 12/13, 3-4.
- "Marcello Truzzi, On Pseudo-Skepticism" Zetetic Scholar (1987) No. 12/13, 3-4. "Though many in this category who dismiss and ridicule anomaly claims call themselves 'skeptics,' they often are really 'pseudo-skeptics' because they deny rather than doubt anomaly claims"
- Truzzi, ibid, ".. they seem less inclined to take the same critical stance towards orthodox theories. For example, they may attack alternative methods in medicine (e.g., for a lack of double-blind studies) while ignoring that similar criticisms can be levelled against much conventional medicine"
- Truzzi, ibid, "those I term scoffers often make judgements without full inquiry"
- Hyman, Ray, 1980. "Pathological Science: Towards a Proper Diagnosis and Remedy," Zetetic Scholar, No. 6, 31-43. Truzzi wrote: ".. they may be more interested in discrediting an anomaly claim than in dispassionately investigating it"
- Truzzi, ibid, "scoffers sometimes manage to discredit anomaly claims (e.g., through ridicule or ad hominem attacks) "
- Truzzi, ibid, "scoffers sometimes manage to discredit anomaly claims .. without presenting any solid disproof
- Truzzi, ibid, "A characteristic of many scoffers is their pejorative characterization of proponents as "promoters" and sometimes even the most protoscientific anomaly claimants are labelled as 'pseudoscientists' or practitioners of 'pathological science.' "
- Marcello Truzzi, "On Pseudo-Skepticism]", Zetetic Scholar, #12-13, 1987. "Critics who assert negative claims, but who mistakenly call themselves 'skeptics,' often act as though they have no burden of proof placed on them at all, though such a stance would be appropriate only for the agnostic or true skeptic"
- Truzzi, ibid, ".. the true skeptic does not assert a claim, he has no burden to prove anything. He just goes on using the established theories of 'conventional science' as usual. But if a critic asserts that there is evidence for disproof, that he has a negative hypothesis — saying, for instance, that a seeming psi result was actually due to an artifact — he is making a claim and therefore also has to bear a burden of proof."
- Truzzi, ibid, ".. many critics seem to feel it is only necessary to present a case for their counter-claims based upon plausibility rather than empirical evidence"
- Truzzi, ibid, "Showing evidence is unconvincing is not grounds for completely dismissing it."
- Truzzi, ibid, "Some proponents of anomaly claims, like some critics, seen unwilling to consider evidence in probabilistic terms, clinging to any slim loose end as though the critic must disprove all evidence ever put forward for a particular claim."
- ECEN 3070 - "Edges of Science", Spring Semester Spring 2006
- Human Energy Systems Laboratory, University of Arizona
- http://www.csicop.org/si/2003-01/medium.html "How Not to Test Mediums: Critiquing the Afterlife Experiments"
- Charles Dudley Warner, Editor, Library Of The World's Best Literature Ancient And Modern, Vol. II, 1896. Online at Project Gutenberg (eg. here)
- H. L. (Henry Louis) Mencken, The Philosophy of Friedrich Nietzsche (1908) publ. T.F. Unwin. Reprinted in Friedrich Nietzsche, Originally published: Boston : Luce and Co., 1913. p.30.
- Alasdair MacIntyre "Foreword" to the book Pragmatism and Realism by Frederick L. Will (1997) quoting his earlier paper "Is There a Problem of Induction?" Journal of Philosophy, Vol. 39, No. 19 (Sep. 10, 1942), pp. 505-513
- John E. Sitter, "The Argument of Pope's Epistle to Cobham" Studies in English Literature, 1500-1900, Vol. 17, No. 3, Restoration and Eighteenth Century (Summer, 1977), pp. 435-449
- Truzzi, ibid, "A characteristic of many scoffers is their pejorative characterization of proponents as 'promoters' and sometimes even the most protoscientific anomaly claimants are labelled as "pseudoscientists" or practitioners of 'pathological science.' "
- C. Eugene Emery, Jr., "CD-ROM encyclopedias: how does their coverage of pseudoscience topics rate?", Skeptical Inquirer, Nov-Dec, 1996
- Truzzi, Marcello, "On Pseudo-Skepticism". Anomalist. (Commentary)
- Truzzi, Marcello, "On Some Unfair Practices towards Claims of the Paranormal". Oxymoron, 1998
- Drasin, Daniel, "Zen and the Art of Debunkery". aol.com, 1997.
- Milton, Richard, "Scientific skepticism".
- Mooney, Chris, "Abuses of Skepticism : Doubting is a powerful tool, but it can definitely be taken too far". CSICOP, December, 2003.
- Haack, Susan, "Science, Scientism, and Anti-Science in the Age of Preposterism". CSICOP, December 1997.
- Hall, Stephanie A. "Folklore and the Rise of Moderation Among Organized Skeptics" Paper presented at the 1999 Annual Meeting of the American Folkore Society
- Sofka, Michael D., "Myths of Skepticism". ISUNY, March, 2002.
- Beaty, William J., "Symptoms of Pathological Sketicism". 1996.
- Hyman, Ray, "Proper Criticism". (csicop.org)
- Martin, Brian, "Strategies for dissenting scientists". Society for Scientific Exploration. Journal of Scientific Exploration, Volume 12 No 4. 1998. (PDF)
- Baez, John, "The crackpot index : Method for rating potentially revolutionary contributions to physics.".
- Kruger, Justin, and David Dunning "Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments". Department of Psychology, Cornell University.
- Debunking Pseudo-Skeptical Arguments against Paranormal and Psychic Phenomena by Winston Wu
- Wilson, Robert Anton, interview in which he discusses CSICOP and pseudoskeptism, what he calls "irrational rationalists" and "fundamentalist materialism"
- Sarma, Amardeo, Misguided Stigmatization of "Organized Skepticism"