Faulty arguments field guide

What goes wrong in an exchange between people: 153 moves in 19 families, each marked with what kind of wrong it is.

A bias is something that happens to you. A fallacy is a move somebody makes.

That difference is not a nicety. It decides what a counter-move can be: against a bias you change the conditions, and against a fallacy you say something back.

Most of these are not always fallacies. Most are good arguments used where their questions fail.

Appeal to authority is how you know nearly everything you know. A slippery slope is sometimes a correct forecast. Ad hominem is how a court tests a witness.

What kind of wrong it is

The order forces precision. An entry is asked first whether structure alone condemns it; then whether the defect is in meaning; then whether a real scheme is being abused; then whether the dispute is about what counts as proof; and only what remains is a matter of conduct.

Most of them are good arguments, misused

Counted honestly and printed at the front: this is what the collection is actually made of.

Where the weight sits

Grouped by what the move does, not by the Latin. The evidence families carry a third of the guide between them.

One mind, one group, one exchange

These are the first three volumes of a set of five, built on the same engine and meant to be read together. The fourth catalogues the working defaults people choose on purpose in order to think well, and the fifth the false certainties of one field, education. Nothing is repeated between them: where a phenomenon belongs to two, it is written once, in the guide whose question it answers, and cross-referenced from the other.

Who is speaking

Moves that answer the person instead of the argument, and moves that borrow authority the speaker has not earned.

Answering the person instead of the argument

The oldest family, the most recognised, and the one most often mis-charged: sometimes the person is the evidence.

Ad hominem, abusive

The arguer is attacked in place of the argument, on grounds that would not bear on the claim even if every word of the attack were true.

Ad hominem, circumstantial

The arguer’s position, interest or circumstances are offered as the reason his argument fails.

Ad hominem, bias

The arguer is said to be so committed to a side that nothing he says on the subject can count.

Tu quoque

The argument is answered by showing that the arguer does not live by it.

Poisoning the well

Adverse information about the arguer is supplied before he speaks, so that whatever he says arrives already discounted.

Guilt by association

A claim or a person is discredited by naming somebody disreputable who shares the position.

Reductio ad Hitlerum

A position is refuted by pointing out that the Nazis, or some comparable party, also held it.

Genetic fallacy

A claim is judged by where it came from rather than by what supports it now.

Chronological snobbery

A view is dismissed because of when it was held rather than because of what is wrong with it.

Bulverism

The arguer explains why you hold your mistaken view before establishing that it is mistaken.

Appeal to motive

An argument is dismissed by supplying a motive for making it.

Abusive analogy

The arguer is compared to something contemptible, and the comparison is offered as though it were an argument.

The courtier’s reply

A criticism is refused on the ground that the critic has not read enough of the literature he is criticising.

Borrowing weight from who holds a view, or how many do

Nearly everything you know, you know on somebody else’s authority. That is the reason this family is difficult.

Appeal to inappropriate authority

An expert opinion is cited where the expert is not an authority on the question, or where the question is not one authority can settle.

Ipse dixit

A claim is offered with no support beyond the fact that it has been asserted.

Appeal to anonymous authority

Authority is invoked without being named, so that it cannot be checked.

Appeal to the people

A claim is supported by the number of people who accept it.

Appeal to common practice

A practice is defended on the ground that it is what everybody does.

Appeal to tradition

PRESUMPTIVE · a sound defeasible scheme, used where its questions fail

Appeal to novelty

FIG 22 — EACH CYCLE MADE THE SAME CLAIM AND FORGOT THE LAST

Appeal to nature

Something is held to be good because it is natural, or bad because it is not.

Appeal to wealth and poverty

A claim is supported by the prosperity of the person making it, or by their lack of it.

The Galileo gambit

Rejection by the established view is offered as evidence that the view is right.

Blinding with science

Technical language and apparatus are used to make a claim unchallengeable rather than clearer.

What is at issue

Moves that change the subject, and moves that apply pressure where a reason is owed.

Answering something adjacent

The argument is not met. Something near it is met instead, and met convincingly.

Red herring

The subject under discussion is replaced by a different subject, and the replacement is not announced.

Straw man

The opponent’s position is restated in a weaker form and the weaker form is refuted.

Weak man (nut-picking)

The feeblest real holder of a position is selected, defeated, and the defeat reported as a defeat of the position.

Hollow man

A position is attributed to an opponent who cannot be shown to exist, and is then refuted.

Ignoratio elenchi

A conclusion is established soundly, and it is not the conclusion that was owed.

Whataboutism

A charge is met with a charge against the accuser, and the first charge is left where it fell.

Trivial objections

A minor and genuine defect in a case is treated as sufficient reason to reject the whole of it.

Resort to humour or ridicule

The argument is answered with a joke, and the laughter is allowed to stand in place of a reply.

Argument by innuendo

A charge is conveyed without being asserted, so that it can be understood and cannot be answered.

Thought-terminating cliché

A short, final-sounding phrase is produced where an argument would have to begin, and the question closes.

Drawing the wrong conclusion

Evidence that supports one conclusion is used to announce a different and usually stronger one.

Giving a reason to accept rather than a reason to believe

Every entry here supplies a motive where a ground was owed.

Appeal to force

A penalty is attached to disagreement, and the penalty is offered in the place a reason should occupy.

Appeal to fear

A frightening outcome the speaker does not control is described, and the description is offered in place of the case.

Appeal to pity

Distress is presented where a ground was owed, so that refusing the claim becomes a refusal of the sufferer.

Appeal to flattery and to spite

The hearer is offered a compliment, or an enemy’s discomfort, as his reason for agreeing.

Appeal to consequences

A proposition is affirmed or denied on the strength of what would follow from accepting it.

Wishful thinking

A proposition is believed because it would be good if it were so.

Appeal to self-interest

A benefit to the hearer is supplied in place of a reason for the claim.

The Kafkatrap

Denial of the charge is counted as evidence for it, so that no answer is available to the accused.

The words

Where the inference is sound and the meaning shifts underneath it, and where a definition is doing the arguing.

The inference is sound; the meaning moved

A term is used twice and means two things, and the argument runs on the join.

Equivocation

A term keeps its shape across an argument and changes its sense, so that a valid-looking inference joins two claims that are not about the same thing.

Amphiboly

The ambiguity sits in the grammar rather than in any word, so one sentence yields two readings and the argument quietly takes the one it needs.

Accent

Meaning is changed by where the stress falls, or by which part of a passage is reproduced, while every word attributed to the speaker is one he said.

Illicit contrast

What a statement implies but does not assert is treated as though it had been asserted, so that a contrast the speaker never made is used as a premise.

Hedging

The wording is chosen in advance to be loose enough that any outcome can afterwards be claimed as the one predicted.

Concealed quantification

A statement about a class is made without saying how much of the class it covers, so that it can be defended as “some” and used as “all”.

If by whiskey

Both sides of a question are answered with equal warmth, each under a different sense of the key word, so that a position appears to have been taken and none has.

Winning by deciding what the words mean

The argument is never joined, because the boundary of the term keeps moving to wherever it needs to be.

No true Scotsman

A counterexample is met by narrowing the definition of the subject term until the counterexample no longer falls under it.

Motte-and-bailey

Two claims share a name, one striking and wanted, one modest and defensible, and the arguer occupies whichever the moment requires.

Definitional retreat

A term is redefined in the middle of an argument so that an objection made against the original meaning no longer applies.

Persuasive definition

A familiar word keeps its emotive force while its descriptive content is quietly changed, so that approval or disapproval is transferred to something new.

Definist fallacy

A contested term is defined into another term, so that a substantive question is settled by the definition rather than by evidence.

Etymological fallacy

A word’s origin is offered as evidence of what it now means, or of what the thing it names ought to be.

Reification

An abstraction, a construct or a statistic is treated as a concrete thing with properties and powers of its own.

Question-begging language (loaded words)

The conclusion is carried by the choice of words rather than by anything asserted, so that accepting the description concedes the argument.

The continuum fallacy and line-drawing

A distinction is rejected because no sharp boundary can be drawn between its ends, or a boundary is rejected because any particular placing of it would be arbitrary.

The structure

The fallacies that structure alone condemns, the arguments that assume what they set out to show, and the ones that contradict themselves.

Condemned by structure alone

The only family in the guide with no legitimate version. These do not have a good use; they have a resemblance to one.

Affirming the consequent

The consequent of a conditional is found to hold and the antecedent is inferred from it.

Denying the antecedent

The antecedent of a conditional is found not to hold and the consequent is denied on that ground.

Affirming a disjunct

One member of an either-or is found to hold and the other is denied on that ground alone.

Undistributed middle

Two classes are linked through a shared term that was never taken in its whole extent.

Illicit major and illicit minor

A term is taken in its whole extent in the conclusion having been taken in part only in the premise.

Four terms

A syllogism appears to have three terms and has four, because one word has been used in two senses.

Exclusive premises

A conclusion is drawn from two premises both of which are negative, from which nothing follows.

Positive conclusion from a negative premise

An affirmative conclusion is drawn where one of the premises denies rather than affirms.

False conversion

A categorical statement is reversed, subject for predicate, where its form does not permit it.

Existential fallacy

A conclusion asserting that something exists is drawn from premises that assert only universals.

The conclusion is already in the premises

The argument is valid. That is the difficulty: every one of these is valid, and none of them gives you a reason.

Begging the question

The conclusion is assumed among the premises, so the argument is valid and supplies no reason to accept it.

Circular reasoning

The conclusion supports a premise which supports the conclusion, around a loop wide enough to be lost.

Question-begging definition

A term is defined so that the disputed conclusion follows from the meaning rather than from any evidence.

Loaded question

A question is put whose presupposition cannot be rejected by any answer it allows.

Stolen concept

A concept is used in the act of denying something the concept depends on.

Unaccepted enthymeme

An argument is left with a premise unstated which the audience does not in fact grant.

Unwarranted assumption

An argument rests on a proposition that is neither stated, defended, nor of a kind that could safely be taken for granted.

Premises that cannot all be true

A small family, and a decisive one: an inconsistent set proves anything, which is another way of saying it proves nothing.

Contradictory premises

The premises offered cannot all be true, so they establish the conclusion and its denial equally.

Conclusion denying the premises

The conclusion, if accepted, undermines the premises that were used to reach it.

Kettle logic

Several defences are offered together, each adequate alone, which cannot all be true at once.

Masked man

Two terms for the same thing are swapped inside a claim about what somebody knows or believes, and the claim changes truth value.

The evidence

Too few cases, the wrong cause, numbers asked to carry more than they can, comparisons that do not hold, and choices narrowed before anyone chooses.

From too few, or from the wrong ones

Every generalisation runs ahead of its evidence. The question is by how much, and whether the sample could have shown otherwise.

Hasty generalisation

A general claim is drawn from a sample too small to have shown anything else.

Unrepresentative sample

A generalisation is drawn from cases selected in a way that is related to what is being measured.

Anecdotal evidence

A single vivid case is offered where a rate is required.

Accident

A sound general rule is applied to a case that lacks the feature the rule was made for.

Converse accident

A general rule is built out of a case that was exceptional in the respect that matters.

Texas sharpshooter

The hypothesis is drawn round the data after the data have been seen, and then tested on the same data.

Cherry-picking

The cases that support the conclusion are reported and the cases that do not are left out.

One-sided assessment

A document that undertook to weigh a question presents only the considerations on one side of it.

Essentialising

A regularity observed in a group is explained by an inner nature the group members are taken to share.

Overwhelming exception

A generalisation is stated with its force intact and qualified until almost nothing is left inside it.

Sequence, correlation, and the story that joins them

The commonest family in public argument, and the one where the fallacy and the sound inference look most alike.

Post hoc ergo propter hoc

One event is taken to have caused another because it came first.

Cum hoc ergo propter hoc

Two things found together are taken to stand in a causal relation on that ground alone.

Ignoring a common cause

A correlation produced by a third factor acting on both variables is reported as a link between them.

Reverse causation

The effect is named as the cause and the cause as the effect.

Causal oversimplification

One contributing cause is named as the cause of an outcome that several conditions jointly produced.

Necessary and sufficient

A condition without which the outcome cannot occur is treated as one that brings it about, or the reverse.

Causal slippery slope

A first step is opposed because it is forecast to set off a chain of consequences ending somewhere unacceptable.

Precedential slippery slope

A decision is opposed not for its own consequences but for what it would commit the decider to next.

Proximate and ultimate

An explanation at one causal level is offered as refuting an explanation at another.

A figure used as though it settled something

Numbers do not argue. They are premises, and they can be irrelevant, unrepresentative or more precise than their source.

Base rate neglect

A test result or a match is turned into a probability about the case without the prevalence of the condition being used.

False precision

A figure is given to a sharpness its source cannot support, and the sharpness is what persuades.

Ex post facto statistics

The improbability of an event is calculated after the event has been singled out, and the improbability is offered as evidence.

The gambler’s fallacy

A run of one outcome in an independent process is offered as a reason to expect the other.

The regression fallacy

A movement back towards the average is explained by whatever happened in between.

Misuse of the average

A figure called the average is offered as the typical case, in a distribution where it is not.

Two things alike in one respect

An analogy is an argument, with a suppressed premise: that the respects in which the cases are alike are the respects that matter.

Faulty analogy

Two cases are treated as alike in the respect at issue on the strength of likeness in some other respect.

The analogical fallacy

An analogy drawn to make one point is carried on and made to yield conclusions it was never built to support.

Argument from sign

An observed indicator is taken to establish the condition it usually accompanies.

Refuting the example

An illustration offered in support of a claim is defeated, and the claim is treated as defeated with it.

False equivalence

Two things are placed on a par by a shared feature, where they differ by a wide margin in the respect that matters.

The options are set before anyone chooses

The argument is won in the setting out of the alternatives, and the audience never sees the step.

False dilemma

Two options are presented as the whole field, and a third that was available is not mentioned.

The bogus dilemma

The two alternatives are exhaustive, and at least one of the consequences attached to them does not follow.

Damning the alternatives

A position is established by discrediting the other options on a list the arguer drew up.

The nirvana fallacy

A workable proposal is rejected by comparison with an ideal that is not among the options.

Middle ground

The position between two stated positions is taken to be the correct one because it lies between them.

All or nothing

A matter of degree is argued as though it admitted only the two end states.

What counts as proof

Who has to show what, and the standing confusion between what is the case and what ought to be.

Who has to show what

Most stubborn disagreements are not about evidence. They are about who is required to produce it.

Argument from ignorance

The absence of evidence for a claim is offered as evidence that it is false, or the absence of evidence against it as evidence that it is true.

Shifting the burden of proof

The party who made the claim requires the other party to disprove it.

Argument from incredulity

The arguer’s inability to imagine how something could be so is offered as a reason for thinking it is not so.

God of the gaps

A gap in the available explanation is filled with a preferred explanation, on the ground that nothing else currently occupies it.

Unfalsifiability

A claim is put in a form that no possible observation could count against, and its immunity is then offered as its strength.

Ad hoc rescue

A refuted claim is preserved by adding an assumption whose only support is that it saves the claim.

Moving the goalposts

Evidence of the kind demanded is produced, and a further or different demand is substituted for it.

Special pleading

A rule accepted as general is applied to others and an exemption is claimed in one’s own case without a relevant difference being given.

Countless counterfeits

The sheer number of unreliable reports of something is offered as a reason to think some of them must be reliable.

Proving too much

An argument is shown to be defective by showing that its form would equally establish something the arguer rejects.

What is, and what ought to be

Six entries on the oldest gap in the subject, and on the two distinct fallacies that share the name naturalistic.

The is-ought gap

An evaluative conclusion is drawn from premises that are wholly descriptive.

Naturalistic fallacy

A natural property is offered as the meaning of “good”, so that an evaluative question is answered by a definition.

Moralistic fallacy

A descriptive conclusion is drawn from a premise about what ought to be the case.

Subjectivist fallacy

A claim with a truth-value is reclassified as a matter of taste, and thereby placed beyond assessment.

Relativist fallacy

A claim is conceded as true for the speaker and denied for the hearer, so that a disagreement is dissolved rather than settled.

Explanation taken as excuse

A causal account of why something happened is answered as though it were a justification of it.

The exchange itself

Moves with no defect in the argument at all, where the fault is in the conduct — including the fault of calling everything a fallacy.

No defect in any premise; the defect is in the conduct

The argument is not beaten. The other party is, by volume, repetition or sheer duration.

The Gish gallop

So many claims are made so quickly that answering any of them costs more time than the audience will give.

Proof by verbosity

The argument is made too long and too dense to be examined, and the difficulty of examining it is taken for strength.

Argument by repetition

A claim is repeated until familiarity does the work that evidence did not.

Sealioning

Relentless, courteous requests for evidence are used to exhaust rather than to learn.

Just asking questions

An assertion is made in the form of a question, so that it need not be defended.

The firehose of falsehood

High-volume, multi-channel, rapid and inconsistent messaging is used to make the truth unlocatable rather than to establish a claim.

The runaway train

A sequence of steps is taken so rapidly and with such momentum that no individual step is examined.

What this guide can be misused for

The most important family in the book, and the reason it has eight parts rather than seven.

Argument from fallacy

A conclusion is treated as false because the argument offered for it was bad.

The fallacy fork

Fallacies as strictly defined are almost never committed; the moves that are common almost never meet the strict definition.

Logic-chopping

A fallacy label is used to end an exchange rather than to improve it.

Inflation of conflict

Disagreement among experts is taken to show that nothing in the field is known.

Tone policing

The manner in which an argument was made is treated as a reason not to address it.

The free speech fallacy

The right to hold a view is offered as a reason to accept it, or as a defence against its being examined.

The repair kit

What a good argument owes its reader, and the eight moves that make an exchange better rather than only catching it out.

The constructive half

Eight procedures rather than eight faults. A catalogue of what not to do is only half an instrument.

The critical question

Every defeasible argument comes with a fixed set of questions it must be able to answer, and asking one is the whole counter-move.

The Toulmin layout

Six parts — claim, grounds, warrant, backing, qualifier, rebuttal — that make visible the step an argument usually leaves out.

The principle of charity

Argue against the strongest version of what the other party said, including the parts they left out.

Steel-manning

State the other side’s case better than they did, and then answer that.

The self-destructive argument method

Turn the argument on the position it was offered to support, and show that it defeats itself.

The absurd counterexample method

Construct an argument of the same form whose conclusion is plainly false.

Naming the burden

Settle who has to show what, before the evidence is discussed.

Conceding well

Give up the part of your position that has been defeated, explicitly, and keep arguing for the rest.

Two hundred and seventy-four works

Every entry names what it rests on, and the reference list holds all of them. Where a move has no literature and only an origin, the entry says so instead.

Every entry in this guide is indexed, with its definition, at https://www.geraldajam.com/library/glossary/field-guides/faulty-arguments-field-guide.