You might save yourself some time and catch more inaccuracies. Being generally aware of common and informal fallacies does help dearly in the writing of sound philosophy.

Would I be any closer to the correct apprehension of reality/truth? — Posty McPostface

Perhaps...

A) Just how long is the list of logical fallacies? Is there a finite number? Do people make up new logical fallacies?

You may not have stumbled on a logical fallacy, but you could still be dead wrong. Is outright lying a logical fallacy? What about revealing truth that seems logically flawed?

Perhaps — VagabondSpectre

But then again, perhaps not.

No. Aside from the fact that no one perfectly adheres to rules even if they believe they ought to l, what counts as a logical fallacy is relative to the logic you're using. Ergo, you may find out you were reasoning according to the wrong logic in some domain and thus have been reasoning fallaciously.

Perhaps... — VagabondSpectre

So, is that a yes or no?

But then again, perhaps not. — Bitter Crank

So, maybe?

No. Aside from the fact that no one perfectly adheres to rules even if they believe they ought to l, what counts as a logical fallacy is relative to the logic you're using. Ergo, you may find out you were reasoning according to the wrong logic in some domain and thus have been reasoning fallaciously. — MindForged

I don't understand. I don't know if there's a theorem stating that if something in base one logic, applies universally to all other logics? Meaning, if I'm correct in one domain of logic, then by extension it should apply to all other domains of logic.

If I were aware of the entire list of logical fallacies, would I be exempt from making wrong/bad inferences?

Would I be any closer to the correct apprehension of reality/truth? — Posty McPostface

There is only one true logical fallacy - the Logical Fallacy Fallacy. It is using the term "logical fallacy" without understanding the underlying basis. If you can't describe what the issue is with another person's argument without saying "XYZ Fallacy" then you have committed this fallacy.

If you disagree with another persons argument, you have to be able to express that disagreement in plain language without using labels or catch words. The term "logical fallacy" is just a lazy way of not having to think your position through.

There is only one true logical fallacy - the Logical Fallacy Fallacy. It is using the term "logical fallacy" without understanding the underlying basis. If you can't describe what the issue is with another person's argument without saying "XYZ Fallacy" then you have committed this fallacy.

If you disagree with another persons argument, you have to be able to express that disagreement in plain language without using labels or catch words. The term "logical fallacy" is just a lazy way of not having to think your position through. — T Clark

This is golden. So, pointing out fallacies is a fallacy of trying to disregard the whole argument based on the occurrence of a fallacy. I'd say that's uncharitable and insincere.

I have one for you. It's called the 'psychological fallacy', where one points out that someone is deriving a position or argument based solely on psychological needs. As if everything were driven by psychological need...

I have one for you. It's called the 'psychological fallacy', where one points out that someone is deriving a position or argument based solely on psychological needs. As if everything were driven by psychological need... — Posty McPostface

Then say "Your argument does not address the logical basis of my position. You are only expressing your preference, your psychological predelection, desire, or need, which is not relevant to my position."

It's really insidious isn't it? One of the more treacherous one's out there.

It's really insidious isn't it? One of the more thorny one's out there. — Posty McPostface

I don't understand your comment - are you disagreeing with me or disagreeing? You are guilty of the Lack of Clarity Logical Fallacy.

This is golden — Posty McPostface

Yes, T Clark gave you good advice.

If you disagree with another persons argument, you have to be able to express that disagreement in plain language without using labels or catch words. — T Clark

Say what you mean, and mean what you say.

BTW, I don't think you have a big problem in this area. When you set out to express yourself clearly, you are clear.

I don't understand your comment - are you disagreeing with me or disagreeing? You are guilty of the Lack of Clarity Logical Fallacy. — T Clark

I'm agreeing obviously. How can I disagree?

BTW, I don't think you have a big problem in this area. When you set out to express yourself clearly, you are clear. — Bitter Crank

My first thought when I saw your new icon was trepanation. My second was that the bit seemed a bit large.

Nobody is going to read this because it is too long, but I'm quoting it just because it is long.

Formal fallacies[edit]
Main article: Formal fallacy
A formal fallacy is an error in logic that can be seen in the argument's form.[4] All formal fallacies are specific types of non sequiturs.

Appeal to probability – a statement that takes something for granted because it would probably be the case (or might be the case).[5][6]
Argument from fallacy (also known as the fallacy fallacy) – assumption that if an argument for some conclusion is fallacious, then the conclusion is false.[7]
Base rate fallacy – making a probability judgment based on conditional probabilities, without taking into account the effect of prior probabilities.[8]
Conjunction fallacy – assumption that an outcome simultaneously satisfying multiple conditions is more probable than an outcome satisfying a single one of them.[9]
Masked-man fallacy (illicit substitution of identicals) – the substitution of identical designators in a true statement can lead to a false one.[10]
Propositional fallacies[edit]
A propositional fallacy is an error in logic that concerns compound propositions. For a compound proposition to be true, the truth values of its constituent parts must satisfy the relevant logical connectives that occur in it (most commonly: <and>, <or>, <not>, <only if>, <if and only if>). The following fallacies involve inferences whose correctness is not guaranteed by the behavior of those logical connectives, and hence, which are not logically guaranteed to yield true conclusions.
Types of propositional fallacies:

Affirming a disjunct – concluding that one disjunct of a logical disjunction must be false because the other disjunct is true; A or B; A, therefore not B.[11]
Affirming the consequent – the antecedent in an indicative conditional is claimed to be true because the consequent is true; if A, then B; B, therefore A.[11]
Denying the antecedent – the consequent in an indicative conditional is claimed to be false because the antecedent is false; if A, then B; not A, therefore not B.[11]
Quantification fallacies[edit]
A quantification fallacy is an error in logic where the quantifiers of the premises are in contradiction to the quantifier of the conclusion.
Types of Quantification fallacies:

Existential fallacy – an argument that has a universal premise and a particular conclusion.[12]
Formal syllogistic fallacies[edit]
Syllogistic fallacies – logical fallacies that occur in syllogisms.

Affirmative conclusion from a negative premise (illicit negative) – a categorical syllogism has a positive conclusion, but at least one negative premise.[12]
Fallacy of exclusive premises – a categorical syllogism that is invalid because both of its premises are negative.[12]
Fallacy of four terms (quaternio terminorum) – a categorical syllogism that has four terms.[13]
Illicit major – a categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion.[12]
Illicit minor – a categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion.[12]
Negative conclusion from affirmative premises (illicit affirmative) – a categorical syllogism has a negative conclusion but affirmative premises.[12]
Fallacy of the undistributed middle – the middle term in a categorical syllogism is not distributed.[14]
Modal fallacy – confusing possibility with necessity.[15]
Informal fallacies[edit]




Main article: Informal fallacy
Informal fallacies – arguments that are fallacious for reasons other than structural (formal) flaws and usually require examination of the argument's content.[16]

Argument to moderation (false compromise, middle ground, fallacy of the mean, argumentum ad temperantiam) – assuming that the compromise between two positions is always correct.[17]
Continuum fallacy (fallacy of the beard, line-drawing fallacy, sorites fallacy, fallacy of the heap, bald man fallacy) – improperly rejecting a claim for being imprecise.[18]
Correlative-based fallacies
Suppressed correlative – a correlative is redefined so that one alternative is made impossible.[19]
Divine fallacy (argument from incredulity) – arguing that, because something is so incredible/amazing/ununderstandable, it must be the result of superior, divine, alien or paranormal agency.[20]
Double counting – counting events or occurrences more than once in probabilistic reasoning, which leads to the sum of the probabilities of all cases exceeding unity.
Equivocation – the misleading use of a term with more than one meaning (by glossing over which meaning is intended at a particular time).[21]
Ambiguous middle term – a common ambiguity in syllogisms in which the middle term is equivocated.[22]
Definitional retreat – changing the meaning of a word to deal with an objection raised against the original wording.[1]
Motte-and-bailey fallacy – The arguer conflates two similar positions, one modest and easy to defend (the "motte") and one much more controversial (the "bailey"). The arguer advances the controversial position, but when challenged, they insist that they are only advancing the more modest position.[23]
Ecological fallacy – inferences about the nature of specific individuals are based solely upon aggregate statistics collected for the group to which those individuals belong.[24]
Etymological fallacy – reasoning that the original or historical meaning of a word or phrase is necessarily similar to its actual present-day usage.[25]
Fallacy of accent – a specific type of ambiguity that arises when the meaning of a sentence is changed by placing an unusual prosodic stress, or when, in a written passage, it's left unclear which word the emphasis was supposed to fall on.
Fallacy of composition – assuming that something true of part of a whole must also be true of the whole.[26]
Fallacy of division – assuming that something true of a thing must also be true of all or some of its parts.[27]
False attribution – an advocate appeals to an irrelevant, unqualified, unidentified, biased or fabricated source in support of an argument.
Fallacy of quoting out of context (contextomy, quote mining) – refers to the selective excerpting of words from their original context in a way that distorts the source's intended meaning.[28]
False authority (single authority) – using an expert of dubious credentials or using only one opinion to sell a product or idea. Related to the appeal to authority fallacy.
False dilemma (false dichotomy, fallacy of bifurcation, black-or-white fallacy) – two alternative statements are held to be the only possible options when in reality there are more.[29]
False equivalence – describing a situation of logical and apparent equivalence, when in fact there is none.
Historian's fallacy – occurs when one assumes that decision makers of the past viewed events from the same perspective and having the same information as those subsequently analyzing the decision.[30] (Not to be confused with presentism, which is a mode of historical analysis in which present-day ideas, such as moral standards, are projected into the past.)
Historical fallacy – a set of considerations is thought to hold good only because a completed process is read into the content of the process which conditions this completed result.[31]
Homunculus fallacy – a "middle-man" is used for explanation; this sometimes leads to regressive middle-men. Explains without actually explaining the real nature of a function or a process. Instead, it explains the concept in terms of the concept itself, without first defining or explaining the original concept. Explaining thought as something produced by a little thinker, a sort of homunculus inside the head, merely explains it as another kind of thinking (as different but the same).[32]
Inflation of conflict – The experts of a field of knowledge disagree on a certain point, so the scholars must know nothing, and therefore the legitimacy of their entire field is put to question.[33]
If-by-whiskey – an argument that supports both sides of an issue by using terms that are selectively emotionally sensitive.
Incomplete comparison – insufficient information is provided to make a complete comparison.
Inconsistent comparison – different methods of comparison are used, leaving one with a false impression of the whole comparison.
Intentionality fallacy – the insistence that the ultimate meaning of an expression must be consistent with the intention of the person from whom the communication originated (e.g. a work of fiction that is widely received as a blatant allegory must necessarily not be regarded as such if the author intended it not to be so.)[34]
Kettle logic – using multiple, jointly inconsistent arguments to defend a position.[dubious – discuss]
Ludic fallacy – the belief that the outcomes of non-regulated random occurrences can be encapsulated by a statistic; a failure to take into account unknown unknowns in determining the probability of events taking place.[35]
McNamara fallacy (quantitative fallacy) – making a decision based only on quantitative observations, discounting all other considerations.
Mind projection fallacy – one's subjective judgments are "projected" to be inherent properties of an object, rather than being related to personal perception of that object.
Moralistic fallacy – inferring factual conclusions from purely evaluative premises in violation of fact–value distinction. For instance, inferring is from ought is an instance of moralistic fallacy. Moralistic fallacy is the inverse of naturalistic fallacy defined below.
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.
Naturalistic fallacy – inferring evaluative conclusions from purely factual premises[36] in violation of fact–value distinction. For instance, inferring ought from is (sometimes referred to as the is-ought fallacy) is an instance of naturalistic fallacy. Also naturalistic fallacy in a stricter sense as defined in the section "Conditional or questionable fallacies" below is an instance of naturalistic fallacy. Naturalistic fallacy is the inverse of moralistic fallacy.
Naturalistic fallacy fallacy[37] (anti-naturalistic fallacy)[38] – inferring an impossibility to infer any instance of ought from is from the general invalidity of is-ought fallacy, mentioned above. For instance, is
P
∨
¬
P
P \lor \neg P does imply ought
P
∨
¬
P
P \lor \neg P for any proposition
P
P, although the naturalistic fallacy fallacy would falsely declare such an inference invalid. Naturalistic fallacy fallacy is an instance of argument from fallacy.
Nirvana fallacy (perfect solution fallacy) – solutions to problems are rejected because they are not perfect.
Onus probandi – from Latin "onus probandi incumbit ei qui dicit, non ei qui negat" the burden of proof is on the person who makes the claim, not on the person who denies (or questions the claim). It is a particular case of the argumentum ad ignorantiam fallacy, here the burden is shifted on the person defending against the assertion. Also known as shifting the burden of proof.
Proof by assertion – a proposition is repeatedly restated regardless of contradiction; sometimes confused with argument from repetition (argumentum ad infinitum, argumentum ad nauseam)
Prosecutor's fallacy – a low probability of false matches does not mean a low probability of some false match being found.
Proving too much – using a form of argument that, if it were valid, could be used to reach an additional, undesirable conclusion.
Psychologist's fallacy – an observer presupposes the objectivity of his own perspective when analyzing a behavioral event.
Referential fallacy[39] – assuming all words refer to existing things and that the meaning of words reside within the things they refer to, as opposed to words possibly referring to no real object or that the meaning of words often comes from how we use them.
Reification (concretism, hypostatization, or the fallacy of misplaced concreteness) – a fallacy of ambiguity, when an abstraction (abstract belief or hypothetical construct) is treated as if it were a concrete, real event or physical entity. In other words, it is the error of treating as a "real thing" something that is not a real thing, but merely an idea.
Retrospective determinism – the argument that because an event has occurred under some circumstance, the circumstance must have made its occurrence inevitable.
Special pleading – a proponent of a position attempts to cite something as an exemption to a generally accepted rule or principle without justifying the exemption.
Improper premise[edit]
Begging the question (petitio principii) – providing what is essentially the conclusion of the argument as a premise.[40][41][42][43]
Loaded label – while not inherently fallacious, use of evocative terms to support a conclusion is a type of begging the question fallacy. When fallaciously used, the term's connotations are relied on to sway the argument towards a particular conclusion. For example, an organic foods advertisement that says "Organic foods are safe and healthy foods grown without any pesticides, herbicides, or other unhealthy additives." Use of the term "unhealthy additives" is used as support for the idea that the product is safe.[44]
Circular reasoning (circulus in demonstrando) – the reasoner begins with what he or she is trying to end up with; sometimes called assuming the conclusion.
Fallacy of many questions (complex question, fallacy of presuppositions, loaded question, plurium interrogationum) – someone asks a question that presupposes something that has not been proven or accepted by all the people involved. This fallacy is often used rhetorically so that the question limits direct replies to those that serve the questioner's agenda.
Faulty generalizations[edit]
Faulty generalizations – reach a conclusion from weak premises. Unlike fallacies of relevance, in fallacies of defective induction, the premises are related to the conclusions yet only weakly buttress the conclusions. A faulty generalization is thus produced.

Accident – an exception to a generalization is ignored.[45]
No true Scotsman – makes a generalization true by changing the generalization to exclude a counterexample.[46]
Cherry picking (suppressed evidence, incomplete evidence) – act of pointing at individual cases or data that seem to confirm a particular position, while ignoring a significant portion of related cases or data that may contradict that position.[47]
Survivorship bias – a small number of survivors of a given process are actively promoted while completely ignoring a large number of failures
False analogy – an argument by analogy in which the analogy is poorly suited.[48]
Hasty generalization (fallacy of insufficient statistics, fallacy of insufficient sample, fallacy of the lonely fact, hasty induction, secundum quid, converse accident, jumping to conclusions) – basing a broad conclusion on a small sample or the making of a determination without all of the information required to do so.[49]
Inductive fallacy – A more general name to some fallacies, such as hasty generalization. It happens when a conclusion is made of premises that lightly support it.
Misleading vividness – involves describing an occurrence in vivid detail, even if it is an exceptional occurrence, to convince someone that it is a problem.
Overwhelming exception – an accurate generalization that comes with qualifications that eliminate so many cases that what remains is much less impressive than the initial statement might have led one to assume.[50]
Thought-terminating cliché – a commonly used phrase, sometimes passing as folk wisdom, used to quell cognitive dissonance, conceal lack of thought-entertainment, move on to other topics etc. but in any case, end the debate with a cliché—not a point.
Questionable cause[edit]
Questionable cause

Cum hoc ergo propter hoc (Latin for "with this, therefore because of this"; correlation implies causation; faulty cause/effect, coincidental correlation, correlation without causation) – a faulty assumption that, because there is a correlation between two variables, one caused the other.[51]
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. The Loch Ness Monster has been seen in this loch. Something tipped our boat over; it's obviously the Loch Ness Monster.[52]
Wrong direction (reverse causation) – cause and effect are reversed. The cause is said to be the effect and vice versa.[53] The consequence of the phenomenon is claimed to be its root cause.
Ignoring a common cause
Fallacy of the single cause (causal oversimplification[54]) – it is assumed that there is one, simple cause of an outcome when in reality it may have been caused by a number of only jointly sufficient causes.
Furtive fallacy – outcomes are asserted to have been caused by the malfeasance of decision makers.
Gambler's fallacy – the incorrect belief that separate, independent events can affect the likelihood of another random event. If a fair coin lands on heads 10 times in a row, the belief that it is "due to the number of times it had previously landed on tails" is incorrect.[55]
Inverse gambler's fallacy
Regression fallacy – ascribes cause where none exists. The flaw is failing to account for natural fluctuations. It is frequently a special kind of post hoc fallacy.
Relevance fallacies[edit]
Appeal to the stone (argumentum ad lapidem) – dismissing a claim as absurd without demonstrating proof for its absurdity.[56]
Argument from ignorance (appeal to ignorance, argumentum ad ignorantiam) – assuming that a claim is true because it has not been or cannot be proven false, or vice versa.[57]
Argument from incredulity (appeal to common sense) – "I cannot imagine how this could be true; therefore, it must be false."[58]
Argument from repetition (argumentum ad nauseam, argumentum ad infinitum) – repeating an argument until nobody cares to discuss it any more;[59][60] sometimes confused with proof by assertion
Argument from silence (argumentum ex silentio) – assuming that a claim is true based on the absence of textual or spoken evidence from an authoritative source, or vice versa.[61][62]
Ignoratio elenchi (irrelevant conclusion, missing the point) – an argument that may in itself be valid, but does not address the issue in question.[63]
Red herring fallacies[edit]
A red herring fallacy, one of the main subtypes of fallacies of relevance, is an error in logic where a proposition is, or is intended to be, misleading in order to make irrelevant or false inferences. In the general case any logical inference based on fake arguments, intended to replace the lack of real arguments or to replace implicitly the subject of the discussion.[64][65][66]

Red herring – a speaker attempts to distract an audience by deviating from the topic at hand by introducing a separate argument the speaker believes is easier to speak to.[67] Argument given in response to another argument, which is irrelevant and draws attention away from the subject of argument. See also irrelevant conclusion.

Ad hominem – attacking the arguer instead of the argument.
Poisoning the well – a subtype of ad hominem presenting adverse information about a target person with the intention of discrediting everything that the target person says.[68]
Abusive fallacy – verbally abusing the opponent rather than arguing about the originally proposed argument.[69]
Appeal to motive – dismissing an idea by questioning the motives of its proposer.
Kafka-trapping – A sophistical and unfalsifiable form of argument that attempts to overcome an opponent by inducing a sense of guilt and using the opponent's denial of guilt as further evidence of guilt.[70][71]
Tone policing – focusing on emotion behind (or resulting from) a message rather than the message itself as a discrediting tactic.
Traitorous critic fallacy (ergo decedo) – a critic's perceived affiliation is portrayed as the underlying reason for the criticism and the critic is asked to stay away from the issue altogether.
Appeal to authority (argumentum ad verecundiam) – an assertion is deemed true because of the position or authority of the person asserting it.[72][73]
Appeal to accomplishment – an assertion is deemed true or false based on the accomplishments of the proposer.[74]
Courtier's Reply – a criticism is dismissed by claiming that the critic lacks sufficient knowledge, credentials, or training to credibly comment on the subject matter.
Appeal to consequences (argumentum ad consequentiam) – the conclusion is supported by a premise that asserts positive or negative consequences from some course of action in an attempt to distract from the initial discussion.[75]
Appeal to emotion – an argument is made due to the manipulation of emotions, rather than the use of valid reasoning.[76]
Appeal to fear – an argument is made by increasing fear and prejudice towards the opposing side[77][78]
Appeal to flattery – an argument is made due to the use of flattery to gather support.[79]
Appeal to pity (argumentum ad misericordiam) – an argument attempts to induce pity to sway opponents.[80]
Appeal to ridicule – an argument is made by presenting the opponent's argument in a way that makes it appear ridiculous.[81][82]
Appeal to spite – an argument is made through exploiting people's bitterness or spite towards an opposing party.[83]
Wishful thinking – a decision is made according to what might be pleasing to imagine, rather than according to evidence or reason.[84]
Appeal to nature – judgment is based solely on whether the subject of judgment is 'natural' or 'unnatural'.[85] (Sometimes also called the "naturalistic fallacy", but is not to be confused with the other fallacies by that name)
Appeal to novelty (argumentum novitatis, argumentum ad antiquitatis) – a proposal is claimed to be superior or better solely because it is new or modern.[86]
Appeal to poverty (argumentum ad Lazarum) – supporting a conclusion because the arguer is poor (or refuting because the arguer is wealthy). (Opposite of appeal to wealth.)[87]
Appeal to tradition (argumentum ad antiquitatem) – a conclusion supported solely because it has long been held to be true.[88]
Appeal to wealth (argumentum ad crumenam) – supporting a conclusion because the arguer is wealthy (or refuting because the arguer is poor).[89] (Sometimes taken together with the appeal to poverty as a general appeal to the arguer's financial situation.)
Argumentum ad baculum (appeal to the stick, appeal to force, appeal to threat) – an argument made through coercion or threats of force to support position.[90]
Argumentum ad populum (appeal to widespread belief, bandwagon argument, appeal to the majority, appeal to the people) – a proposition is claimed to be true or good solely because majority or many people believe it to be so.[91]
Association fallacy (guilt by association and honor by association) – arguing that because two things share (or are implied to share) some property, they are the same.[92]
Bare assertion fallacy, also known as ipse dixit – a claim that is presented as true without support, as self-evidently true, or as dogmatically true. This fallacy relies on the implied expertise of the speaker or on an unstated truism.[93][94]
Bulverism (psychogenetic fallacy) – inferring why an argument is being used, associating it to some psychological reason, then assuming it is invalid as a result. It is wrong to assume that if the origin of an idea comes from a biased mind, then the idea itself must also be a falsehood.[33]
Chronological snobbery – a thesis is deemed incorrect because it was commonly held when something else, clearly false, was also commonly held.[95][96]
Fallacy of relative privation (also known as "appeal to worse problems" or "not as bad as") – dismissing an argument or complaint due to the existence of more important problems in the world, regardless of whether those problems bear relevance to the initial argument. First World problems are a subset of this fallacy.
Genetic fallacy – a conclusion is suggested based solely on something or someone's origin rather than its current meaning or context.[97]
Judgmental language – insulting or pejorative language to influence the recipient's judgment.
Moralistic fallacy (the inverse of naturalistic fallacy) – statements about what is, on the basis of claims about what ought to be.
Naturalistic fallacy (is–ought fallacy,[98] naturalistic fallacy[99]) – claims about what ought to be, on the basis of statements about what is.
Pooh-pooh – dismissing an argument perceived unworthy of serious consideration.[100]
Straw man fallacy – an argument based on misrepresentation of an opponent's position.[101]
Texas sharpshooter fallacy – improperly asserting a cause to explain a cluster of data.[102]
Tu quoque ("you too", appeal to hypocrisy, I'm rubber and you're glue, Whataboutism) – the argument states that a certain position is false or wrong or should be disregarded because its proponent fails to act consistently in accordance with that position.[103]
Two wrongs make a right – occurs when it is assumed that if one wrong is committed, an "equal but opposite" wrong will cancel it out.[104]
Vacuous truth – a claim that is technically true but meaningless, in the form of claiming that no A in B has C, when there are no A in B. For example, claiming that no mobile phones in the room are on when there are no mobile phones in the room at all.
Conditional or questionable fallacies[edit]
Broken window fallacy – an argument that disregards lost opportunity costs (typically non-obvious, difficult to determine or otherwise hidden) associated with destroying property of others, or other ways of externalizing costs onto others. For example, an argument that states breaking a window generates income for a window fitter, but disregards the fact that the money spent on the new window cannot now be spent on new shoes.
Definist fallacy – involves the confusion between two notions by defining one in terms of the other.[105]
Naturalistic fallacy – attempts to prove a claim about ethics by appealing to a definition of the term "good" in terms of either one or more claims about natural properties, sometimes also taken to mean the appeal to nature.[85]
Slippery slope (thin edge of the wedge, camel's nose) – asserting that a relatively small first step inevitably leads to a chain of related events culminating in some significant impact/event that should not happen, thus the first step should not happen. It is, in its essence, an appeal to probability fallacy.[106]

I'm agreeing obviously. How can I disagree? — Posty McPostface

Given the popularity of the use of the term "logical fallacy" I think a lot of people would disagree with me.

Would I be any closer to the correct apprehension of reality/truth? — Posty McPostface

No, I don't think so. There is a difference between logical validity and soundness. Having valid syllogisms doesn't make you any closer to reality, not unless these syllogisms are sound (by having true premises). And having true premises requires non-theoretical commitments, such as the commitment to explore, learn, adapt, etc. Logic is form, sense is data. A computer may be programmed to be completely logical with respect to some input, but if there is no input, the computer has nothing to do.

Nobody is going to read this because it is too long, but I'm quoting it just because it is long. — Bitter Crank

It's all a bunch of bullshit, which may be an example of the Bullshit Fallacy.

Given the popularity of the use of the term "logical fallacy" I think a lot of people would disagree with me. — T Clark

Oh, I'm not so sure about that. It seems reasonable on face value.

My first thought when I saw your new icon was trepanation. My second was that the bit seemed a bit large. — T Clark

Yeah, well, sure: trepanation. Why not?

One needs a big drill bit to get through thick skulls.

I don't understand. I don't know if there's a theorem stating that if something in base one logic, applies universally to all other logics? Meaning, if I'm correct in one domain of logic, then by extension it should apply to all other domains of logic. — Posty McPostface

Let me give an example. In the logic Aristotle developed - known as Syllogistic - an argument with Existential Import was valid. So the following argument was valid in Aristotliean logic:

All winged horses are horses
All winged horses have wings
Therefore some horses have wings

(Form: All A's are B's, All A's are C's, therefore some B's are C)

The first two premises seem clearly true, they're analytic statements. But the logic takes us from 2 obviously true premises to an obviously false conclusion: there are, in fact, no horses with wings. Something has gone wrong with the logic itself. That's why the standard logical systems of our day treat arguments like the above as fallacious arguments, they commit the Existential fallacy.

This is just for completeness sake. It's less common to be using the wrong logic in a way that will matter for everyday reasoning, which uses a weak logic to infer things. I believe my other point about imperfectly following rules is more pertinent to your question.

No, I don't think so. There is a difference between logical validity and soundness. Having valid syllogisms doesn't make you any closer to reality, not unless these syllogisms are sound (by having true premises). And having true premises requires non-theoretical commitments, such as the commitment to explore, learn, adapt, etc. Logic is form, sense is data. A computer may be programmed to be completely logical with respect to some input, but if there is no input, the computer has nothing to do. — darthbarracuda

Yes, we're not talking about epistemic content, yet. Just about the reasoning process itself and the motivations behind it.

One needs a big drill bit to get through thick skulls. — Bitter Crank

You are guilty of the Bit Size Fallacy. Small bits drill more easily through any solid. They would also be less intrusive and probably less likely to lead to infection than large bits.

That's why the standard logical systems of our day treat arguments like the above as fallacious arguments, they commit the Existential fallacy. — MindForged

Can you express your logical disagreement in plain language? If so, why do you need to use the term? If not, how can your use of the term be meaningful?

I believe my other point about imperfectly following rules is more pertinent to your question. — MindForged

Is this about the discrepancy between formal and informal reasoning?

It's just a short hand, it makes no difference. The issue is assuming that a class has members without asserting as a premise that the class has members. If someone is confused about what the term referred to, well, we are on the internet.

The first two premises seem clearly true, they're analytic statements. But the logic takes us from 2 obviously true premises to an obviously false conclusion: there are, in fact, no horses with wings. That's why the standard logical systems of our day treat arguments like the above as fallacious arguments, they commit the Existential fallacy. — MindForged

Well, just confirmed we are not talking about epistemic content yet, but is this logically fallacious? Is the "existential fallacy" really a logical fallacy? The premises may be false, which makes the syllogism not-sound. But it is still valid. So what does fallacy mean here?

Meinong would have said this syllogism is not only valid but can also be sound. Winged horses are horses, even if winged horses don't "exist" in the concrete sense.

Treating this as a logical fallacy seems to commit us to something similar to Descartes' cogito, method of doubt. The fault in the aforementioned syllogism isn't with the syllogism as a form but with its premises, which are reduced to a syllogism as well, which in term has premises that are reduced to even more simple syllogisms, until we get to something indubitable. Unfortunately, the "fact" that winged horses do not exist is by no means indubitable.

Kind of? I'm saying that you could have flawless knowledge of every error in reasoning and still fail to reason perfectly since in practice you will never apply that knowledge infallibly. Like, mathematical logic students and professional logicians aren't immune to common errors in reasoning even if they intellectually know that they're committing a no-no.

It's just a short hand, it makes no difference. The issue is assuming that a class has members without asserting as a premise that the class has members. If someone is confused about what the term referred to, well, we are on the internet. — MindForged

Yes, it does make a difference. The main problem with LFs is that people use them without really understanding what they mean, their logical basis, or how they apply to a particular argument. The most egregious example is the Ad Hominem Fallacy. People misuse that all the time. They use it whenever someone insults them or says uncharitable things about their arguments. The term has a specific meaning which doesn't usually apply to the situation being described. People are even too lazyy to say "Ad Hominem Fallacy." They say "that's ad hom" in a knee-jerk application which really just means "I don't like how you said that."

Well, ↪Posty McPostface just confirmed we are not talking about epistemic content yet, but is this logically fallacious? Is the "existential fallacy" really a logical fallacy? The premises may be false, which makes the syllogism not-sound. But it is still valid. So what does fallacy mean here? — darthbarracuda

"Fallacy" means the conclusion does not follow from the premises. The first two are definitely true, the conclusion is definitely false, and yet Syllogistic (as opposed to classical logic) says the argument form is fine. Yes the Existential fallacy is a fallacy. That argument comes out as invalid in modern systems of logic.

Meinong, unless I'm mistaken, would agree that it's in error. He might think pegasi have being, but not existence in a concrete sense. Then again, I'm not super into Meinongianism so maybe I'm off about it.

1.) All winged horses are horses.
2.) All winged horses have wings.
3.) Therefore, some horses have wings.

This is not quite valid since it is missing the premise that winged horses exist. Inserting this premise makes the syllogism valid but not sound, since the premise is false. But in order to know that this premise is false, one would have to be omniscient. But we are not omniscient.

Isn't this all this amounts to? That humans are not omniscient?