On the Informal Fallacies

Have you discovered a new and aptly named fallacy? Please do share. I accept any fallacy by e-mail.

Fallacy, ergo sum. The philosopher always loves a good fallacy. Students in introductory logic classes are required to memorize lists of them: the fallacy of composition, argument ad hominem, the genetic fallacy, and so on. Some climb beyond fame into infamy, like the naturalistic fallacy which may not be a fallacy at all. Fallacies are so much fun that some authors amplify their arguments by coining a fallacy for their opponents to have committed. This page is a collection of such one-off fallacies from real sources. (To my delight, this rhetorical strategy is not confined to philosophers.)

argumentum ad Gaulum
"If the French do it, it therefore must be good." (Chuck Taggart in his explanation of why tripe is just wrong.)
the boy's club fallacy
Supposing that it cannot be sexist to prefer people because of social connections you have to them or the depth of information you have about them, even though the connections and information are distributed in an inequitable way. For example, "my not picking her (for a student position) was not sexist, since I don't know her at all. But I do know the other (male) candidate, admire his work, etc. So I picked him." (Anne Jacobson at Feminist Philosophers, February 15, 2013)
the Buzz Aldrin fallacy
Inferring from the fact that a discipline doesn't help accomplish a particular goal to the conclusion that the discipline is worthless. (Mark Satta at Blog of the APA, August 12, 2019)
the counterculture fallacy
"...a direct descendant of the Beat fallacy that preceded it by a decade: Lefties of a certain age, like me, still presume, in the face of massive evidence to the contrary, that a conservative who has messed around with mind-altering substances is somehow cooler, less straight, less, well, right-wing, than a conservative who hasn't." (Gary Kamiya in Salon, June 2, 2001)
the covariance fallacy
Presuming that the presence or absent of consensus regarding matters of fact is indicative of agreement or disagreement about the ends with respect to which matters of fact are judged. (Larry Laudan in Science and Values, 1984)
the devil theory fallacy
Attributing to villainy what could simply have resulted from stupidity. (Doc in Robert Heinlein's Logic of Empire, 1941)
the divining rod fallacy
On the basis of an instrument or scale for measurement being problematic, inferring that the property which it measures is not real. "[J]ust because a rod doesn't find water doesn't mean there's no such thing as water." (Keith Payne, Laura Niemi, and John Doris writing on implicit bias at Scientific American, March 27, 2018)
the ecological fallacy
"[A]ttributing absolute badness to styles or features or artists or individual works when, in fact, our true complaint is... relativis[ed]" to contingent facts such as the overuse of style (etc.) (John Holbo, June 25, 2012)
fallacy ex homine
alternately, fallacy ab homuncule. The opposite of ad hominem. A sense of decorum stops anyone from making accusations of some particular dark motive, such as racism, while charges of other dark motives are still hurled around. The result is that the unspeakable dark motive gets a free pass. (John Holbo, March 25, 2010)
fallacies of functional localization
Because an animal can perform a distinct function, it is supposed there is a distinct place in the animal's body where that function is carried out. (Bill Wimsatt in a public lecture on generative entrenchment, 1998)
the fallacy of internal monologue
Considering the paradigm case of a mental event to be a propositional thought is "a classic case of where highly educated people read back their degenerate form of experience onto everybody else." (Wayne Martin in a reading group on intentionality, 1998)
geek social fallacies
The error of taking a social adaptation of being a geek to an unreasonable extreme; for instance, extending excessive tolerance to disruptive members of the community. (Michael Suileabhain-Wilson in an essay on geekdom)
the linguist's fallacy
A scholar's error in "imputing his own sophisticated attitudes to the speakers he is studying." (Max Black in Linguistic Relativity: the Views of Benjamin Lee Whorf, 1956)
the Jedi Master fallacy
Arguing against a just arrangement for people who are not in power on the grounds that the ones in power are mystically attuned and that oppression is the proper order of the universe. Given a mock-latin name, it might be called the argumentum ben kenobi. "[M]ost arguments against TA/RA unionization stem less from a coherent set of arguments, than a semi-inchoate sense that giving organizing rights to Jedi Apprentices will lead to a Great Disturbance in the Force. The obvious rejoinder to this is that professors are not Jedi Masters, and that there is nothing inherent to the balance of the universe that is likely to change if grad students have the right to organize." (Henry Farrell, February 6, 2012)
the ludic fallacy
Presuming that performance on some made-up task will generalize to situations actually encountered in the world. "[T]he set-up of situations in academic-style multiple choice questions, made to resemble 'games' with crisp, unambiguous rules. These rules are divorced from both their environment and their ecology. ... [I]f people often sometimes appear inconsistent, as shown in many 'puzzles,' it is often because it is the exam itself that is wrong." (Nassim Nicholas Taleb in the Freakanomics blog at the New York Times, August 9, 2007)
the Narcissan fallacy
Thinking that objects which are designed for some purpose are themselves goal-directed agents. "[T]he tendency to mistake the reflection of human intentional agency in mindless objects, such as computers, for something analogous to a separate instance of mental agency." (David Bentley Hart writing against Daniel Dennett; The Illusionist, The New Atlantis, Number 53, Summer/Fall 2017, pp. 109-121)
the neosemantic fallacy
Thinking that new language marks genuine novelty, "by the magic of neologisms, which encourage to infer that a new word refers to a new kind of thing." (Joshua Habgood-Coote, who attributes the label to Thi Nguyen; Deepfakes and the epistemic apocalypse, Synthese, 2023)
the Netflix fallacy
This is an interesting specimen, because the author coins it so as to describe his own behavior. Unfortunately, it is not entirely clear what the fallacy is supposed to be. The initial example suggests that it's the irrational decision to pay for something which could possibly to be money-saving but which, as one actually uses it, costs more than it is worth. Later discussion suggests that it's about 'intertemporal decision making': If you choose movies one at a time, then you are apt to pick schlocky entertainments— but if you choose a batch of movies all at once, then you are apt to choose some hifalutin films that you won't actually watch. (Henry Farrell, July 23 and August 2, 2004)
the palm reading fallacy
Expecting psychological or sociological phenomena which occur at the group level to yield predictions about particular group members. "[U]nlike palm readers, research psychologists aren't usually in the business of telling you, as an individual, what your life holds in store." (Keith Payne, Laura Niemi, and John Doris writing on implicit bias at Scientific American, March 27, 2018)
the 'passes for' fallacy
Since much of what has passed for truth, fact, and objective warrant has been nothing of the sort, it is supposed that there is no truth or objectivity. (Susan Haack in Manifesto of a Passionate Moderate, 1998)
the fallacy of physical object primacy
The name given to "giving physical objects and the criteria that apply to them priority over the whole range of describable phenomena." For instance, GE Moore's "thinking that because it makes sense on a given occasion to assert that you and I are seeing numerically the same physical object, say a particular light bulb, it also makes sense to apply the adjective 'numerically the same' to the after-image I have of that light bulb." (Avrum Stroll in Moore and Wittgenstein on Certainty, 1994)
the pleonastic fallacy
Thinking that a difference in kind might only be a tremendous difference in degree. "[T]he attempt to explain away an absolute qualitative difference - such as that between third-person physical events and first-person consciousness - by positing an indefinite number of minute quantitative steps, genetic or structural, supposedly sufficient to span the interval." (David Bentley Hart writing against Daniel Dennett; The Illusionist, The New Atlantis, Number 53, Summer/Fall 2017, pp. 109-121)
the psychological or historical fallacy
"A set of considerations which hold good only because of a completed process is read into the content of the process which conditions this completed result." (John Dewey in The Reflex Arc Concept in Psychology, 1896)
the fallacy of selective emphasis
After abstracting from raw experience, the resultant abstraction is treated as primary and more real than the experience from which it was abstracted. (John Dewey in Experience and Nature)
reductio ad Hitlerum, argumentum ad Nazium
A Nazi would say that; ergo, it's false. (Leo Strauss, perhaps)
the sentimentalist fallacy
"[T]o shed tears over abstract justice and generosity, beauty, etc., and never to know these qualities when you meet them in the street, because the circumstances make them vulgar." (William James in Pragmatism's Conception of Truth, 1907)
the fallacy of unnatural deceleration
One begins by ridiculing the opposition, and this gains so much momentum that one must not only say that they are wrong but also that they are obviously wrong. The rhetorical stance allows for no retreat, making it impossible even to allow that establishing the opposition's wrongness might require reflection or argument. (John Holbo writing against David Bentley Hart, December 9, 2017)
the Wittgenstein fallacy
Inferring "that the profession of philosophy as currently practiced is somehow flawed, because a modern day Wittgenstein would not receive recognition or employment." (Jason Stanley, 2007)