Formal and informal debate becomes corrupted when people call out informal fallacies in their opponents’ arguments where the argument actually had some sense to it and either the fallacy isn’t really a legit fallacy to begin with or it was improperly called out without taking into account contextual nuance that makes the argument actually logical. In this way, calling out so-called fallacies is used to unfairly discredit opponents’ arguments, and thinking in terms of informal fallacies tends to co-opt truly logical thinking. So, in this light, I will explain exactly what’s wrong with many of the popular informal fallacies.
Argument from incredulity – when someone can’t imagine something to be true, and therefore deems it false, or conversely, holds that it must be true because they can’t see how it could be false.
Not being able to see how something could be true or, conversely, how something could be false, is obviously isomorphic to saying “this is how I see it, and I can’t see it any other way,” and this is the fundamental basis for all staunch beliefs, such as beliefs that one may argue for. The only difference in this case is that the arguer presumably lacks the ability to articulate why they see it this way with such surety. That in itself is not necessarily reason to completely dismiss their argument, because if we give them any credit as an intelligent being, then their not being able to see it any other way is significant.
The particular argument also indicates that its purveyor has thought of all the alternative scenarios they could and all have turned up impossible, as opposed to simply single-mindedly clinging to the one possibility they can imagine as many people do, which also adds a bit of credit.
The argument is also stronger if it reflects underlying (if inarticulable) reasoning that others may share; that is, if others witnessing the argument see it similarly.
The argument may also not be meant to be self-contained but rather an opener for further conversation regarding possibilities how something is true or false. E.g., it may be used to prompt the opponent to explain some way they think their position could be true, which the first person will presumably have some argument against.
Slippery slope (thin edge of the wedge, camel’s nose) – asserting that a proposed, relatively small, first action will inevitably lead to a chain of related events resulting in a significant and negative event and, therefore, should not be permitted.
People often call out the “slippery slope” fallacy as if it’s always necessarily invalid, while in fact, many situations are indeed slippery slopes. While a claim that something will likely or inevitably lead to something further may be left unsubstantiated, it still carries weight if it makes intuitive or reasonable sense to other parties that it’s a slippery slope, or that it may be a slippery slope, thus warranting some amount of trepidation surrounding the prospective action.
Appeal to authority (argument from authority, argumentum ad verecundiam) – an assertion is deemed true because of the position or authority of the person asserting it.
Argument from authority is not quite a logical proof, obviously, as authorities can be and have been wrong, but authorities are generally authorities for a reason. They tend to be learned experts on the subject, so an authority’s opinion on the matter is probably more credible than either of the arguers’ opinions alone.
Argument from anecdote – a fallacy where anecdotal evidence is presented as an argument; without any other contributory evidence or reasoning.
This is a big one. The common mentality of denialism, particularly regarding any nonphysical (e.g. spiritual, paranormal, parapsychological, mystical, or divine) phenomena, objects, substances, principles, etc., is greatly facilitated by the illusion that anecdotal evidence is meaningless and totally dismissible, mainly due to the fact that it has a label, “anecdotal evidence.” A truly open-minded approach would carefully analyze and weigh every anecdote one comes across for its likely legitimacy based on various clues, even if uncertain/unproven ones, and then come to a conclusion or likely conclusion based on the sum total of all anecdotal evidence and other reasoning. In other words, anecdotal evidence should carry weight to it, especially when there’s a lot of it, and especially when it seems particularly legitimate, but all too often it’s dismissed out of hand because that’s convenient for maintaining one’s physicalist bias.
I wrote more about this here: https://myriachromat.wordpress.com/2018/04/13/notes-on-science-scientism-mysticism-religion-logic-physicalism-skepticism-etc/#Anecdotal
Magical thinking – fallacious attribution of causal relationships between actions and events. In anthropology, it refers primarily to cultural beliefs that ritual, prayer, sacrifice, and taboos will produce specific supernatural consequences. In psychology, it refers to an irrational belief that thoughts by themselves can affect the world or that thinking something corresponds with doing it.
This is a case in which physicalist/mechanicalist/scientistic bias directly impinges on what’s considered valid or invalid as if it’s an unquestionable, sure thing. It’s not. It’s merely a reflection of the current zeitgeist. Essentially, whether “magical thinking” really constitutes a fallacy or not depends on whether the world really is magical. It’s popular to believe that the idea of magic is nothing but pure fantasy, but there’s on proof that it is, and meanwhile, magical phenomena are regularly experienced by countless people, and there are entire disciplines and bodies of knowledge devoted to magick.
Another example in which the assumption of mechanicalism is baked right into what we call something is the so-called frequency illusion. I wrote about that here https://myriachromat.wordpress.com/2025/03/13/frequency-illusion/ and here https://myriachromat.wordpress.com/2018/04/13/notes-on-science-scientism-mysticism-religion-logic-physicalism-skepticism-etc/#Bias.
Ad hominem – attacking the arguer instead of the argument. (Note that “ad hominem” can also refer to the dialectical strategy of arguing on the basis of the opponent’s own commitments. This type of ad hominem is not a fallacy.)
Arguments against the person are often actually relevant to the legitimacy of the person’s argument. Many traits of human beings, both positive and negative ones, impinge on their ability to form correct opinions.
Of course, one could argue that an argument stands on its own merit and substantiation and thus personal traits have nothing to do with it, but this isn’t fully the case when a statement is being made by an expert/authority figure, and also, to some degree, we should just trust the intelligence and sensibilities of the person making an argument by virtue of them being fellow humans, at least/especially when their argument makes intuitive sense to us, and furthermore, arguments are rarely exactly logical proofs, so there’s always some amount of credentializing involved whether conscious or unconscious, and that credentializing should of course be diminished when we find out pertinent detracting things about their character.
Appeal to nature – judgment is based solely on whether the subject of judgment is ‘natural’ or ‘unnatural’. (Sometimes also called the “naturalistic fallacy”, but is not to be confused with the other fallacies by that name.)
Whether this is a fallacy depends on whether what’s natural really is generally or always better. According to the Wikipedia page for this fallacy, “What is natural is good” has no factual meaning beyond rhetoric in some or most contexts.” This is entirely an assumption. It could easily be that what’s natural is what was meant to be and that what’s unnatural is humans’ endeavors to upset some kind of sublime balance. This could be true if there as any kind of tendency of nature, whether physical or nonphysical/mystical, to arrive at optimal patterns of being.
Besides the possibility that spirit could have had an influence in the development of the natural world, there is an obvious naturalistic argument for natural things being better: the human form evolved in in a natural context, and the processes of life exist within delicate balances that can easily be upset, e.g. by new and unnatural influences such as artificial chemicals in our foods and environment, sedentary lifestyles, a stressful workforce, the easy availability of any amount and any kind of food we want, etc. We know these things cause endless problems. Technology in general is also used to destroy the biosphere, which will eventually result in the destruction of ourselves, and domestication and medical technology in general is causing genetic drift due to largely removing evolutionary stressors, which will continue to make us weaker, dumber, uglier and less durable.
Moving the goalposts (raising the bar) – argument in which evidence presented in response to a specific claim is dismissed and some other (often greater) evidence is demanded.
I can see how moving the goalpost can be problematic, of course, in that if the opponent meets their first standard of convincing and then the person moves the goalpost, it would seem that the matter has been settled and the person is only moving the goalpost out of convenience/desperation. But therte’s more to the story.
First, the opponent meeting the person’s initial demands could merely make the person realize that their initial demands were too lax. Their argument could still be correct, whether out of correct reasoning and/or perspicacity or out of coincidence, in which case demanding an even more stringent goalpost would be prudent.
Second, there was likely no particular reason for the exact level of stringency posed by the first goalpost to begin with. It was just accepted and agreed upon because it was what was presented. So, presenting a further goalpost could just be seen as a recontextualization of the argument that we could also just agree on for the same reasons as the first one.
Kettle logic – using multiple, jointly inconsistent arguments to defend a position.
It’s not actually fair to consider someone’s arguments illegitimate if they contradict each other, for two reasons:
- Any one of the arguments could be legitimate, even if they all can’t, and
- If the only indication that one or more of the arguments is illegitimate is that they contradict each other, then each argument stands no more chance of being illegitimate than the opponent’s argument if they only offer one argument or significantly fewer arguments, because in that case, we wouldn’t know if the opponent’s argument is illegitimate, because the fact that they didn’t happen to raise another argument that contradicts it doesn’t mean it’s necessarily legitimate.
This implies that arguing is a somewhat imprecise, imperfect art and that arguments from either side can easily seem to be strong while not actually being correct.
Reification (concretism, hypostatization, or the fallacy of misplaced concreteness) – treating an abstract belief or hypothetical construct as if it were a concrete, real event or physical entity (e.g.: saying that evolution selects which traits are passed on to future generations; evolution is not a conscious entity with agency).
I’ve seen people pull the alarm on people claiming, or seeming to claim, that evolution has this or that agenda or goal, while in fact evolution is supposed to be a blind, unconscious process devoid of any agency. The problem with this is that, more often than not, such wording is really used as a shortcut, as it would take a lot more words to say something like “the nature of natural selection is such that this or that end result tends to come about,” and furthermore, whether it happens by blind, unconscious processes or via some kind of agency usually/often makes no practical difference for the subject at hand.
Post hoc ergo propter hoc (Latin for ‘after this, therefore because of this’; temporal sequence implies causation) – X happened, then Y happened; therefore X caused Y.
This one seems to be more often not called out as a fallacy of argument, but rather as a fallacy of one’s personal thinking. And I think it can actually be fruitful. While X happening after Y happening obviously doesn’t mean Y necessarily caused X, assuming that it did could greatly speed up one’s practical/usable knowledge of cause and effect, especially where one has other reasons to think there’s probably a causal link between the two, such as a hunch. Such assumption risks being wrong, of course, but the worst that can happen is that trying to put the supposed causal principle to practice would fail. The risk of being wrong about uncertain things seems to be greatly exaggerated by intellectuals in general in comparison to the possible benefits of being right.
Once in IRC, I had the nick post_hoc_reifier, and somebody asked me if I’m more magickal or scientific thinking, and I said both. He said he was too, and that double-jointed people such as him and me are rare.
While we’re on the subject of fallacies, I want to mention one that I see all the time that really grates on me, which really is a fallacy, or at least an improper debate tactic of some sort, that isn’t mentioned in any list. I guess I’ll call it the “last argument fallacy.” It’s when you make a number of independent arguments for your case, any one of which should actually be sufficient to make the case, and the opponent argues only against the last one, or possibly one of the other arguments at random, and the debate continues on from there as if all the other arguments you made don’t matter.
