A debate is scored on its moves, not its volume. This is the house field guide to the fouls — the classic logical fallacies, each with the move, a plain example, and the tell that defeats it. Nothing here is invented: these are the documented canon, taught in logic and rhetoric for centuries. The examples are hypothetical on purpose — we name the move, never a person.
How to use it: a fallacy is a broken argument, not a wrong conclusion. Someone can reach the right answer by a bad road — calling the foul tests the road, not the destination. And the sharpest use is inward: run this list on your own draft first. A voice named for debate must be able to name its own fouls.
The house method ™
Lead with grace. Hit him with kindness. Kill him with the arguments.
Family I — Attacks on the person
Ad Hominem
argumentum ad hominem — “to the man”
Attacking the arguer instead of the argument. Their character, motive, or circumstance is treated as if it refuted what they said.
“You can’t trust her case for the bridge repair — she failed her own driving test twice.” Her driving record has nothing to do with whether the bridge is safe.
The tell: the rebuttal is about the speaker, not the claim. Counter: “Even if that’s true about me, address the point.”
Tu Quoque
“you too” — the appeal to hypocrisy
Deflecting a charge by accusing the accuser of the same thing. Hypocrisy may be real, but it doesn’t make the original point false.
“You say I should quit smoking — but you smoke!” The doctor’s habit doesn’t change what smoking does to your lungs.
The tell: a counter-accusation stands in for an answer. Counter: “My conduct isn’t the question on the table.”
Poisoning the Well
pre-loading the bias
Discrediting a source in advance so nothing they say afterward gets a fair hearing.
“Before he speaks, remember he’s only saying this to sell a book.” The motive is asserted up front to pre-empt the actual argument.
The tell: the discredit comes before the claim, not from it. Counter: “Judge the argument once it’s made.”
Family II — Dodges & distractions
Straw Man
burning the scarecrow
Swapping the opponent’s real argument for a weaker, distorted version — then knocking that one down.
“You want a later curfew? So you want kids out all night with no rules at all.” “Later” was rewritten as “none.”
The tell: “So what you’re really saying is…” followed by something you didn’t say. Counter: restate your actual position and ask them to argue with that.
Red Herring
the scent off the trail
Introducing an irrelevant but engaging point to pull the debate off course.
“Why worry about the budget shortfall when there are children going hungry?” Both matter — but one was raised to bury the other.
The tell: the topic quietly changed and nobody’s answering the first question. Counter: “Good topic — let’s finish this one first.”
Whataboutism
a cousin of tu quoque
Answering a criticism by pointing at someone else’s wrong, so your own never gets examined.
“Our delays are bad? What about the company across town — they’re worse!” Their record doesn’t excuse yours.
The tell: every answer starts with “but what about…”. Counter: “We can grade them next. Right now we’re grading us.”
Gish Gallop
winning by volume
Burying the other side in a flood of weak claims, faster than any one can be answered — then declaring victory by what went unrebutted.
Thirty shaky assertions in two minutes; the reply has time to refute three, so the other twenty-seven are claimed as “unchallenged.”
The tell: quantity is the whole strategy. Counter: pick the load-bearing claim, demolish it slowly, and refuse to be rushed past it.
Family III — Broken structure
Circular Reasoning
petitio principii — begging the question
Smuggling the conclusion into the premise. The argument assumes the very thing it claims to prove.
“This rule is fair because it’s the rule, and rules are fair.” The conclusion is doing the work of the evidence.
The tell: the “because” just restates the claim. Counter: “What’s the reason that isn’t the conclusion again?”
False Dilemma
the false dichotomy — “either/or”
Presenting two options as the only two, when more exist, to force a choice.
“Either we cut the whole program or we go bankrupt.” Trimming, reforming, or refunding it are all missing from the menu.
The tell: only two doors, and one is unthinkable. Counter: “Those aren’t the only choices — here’s a third.”
No True Scotsman
moving the definition
Defending a sweeping claim by redefining the terms to exclude any counterexample.
“No real fan would boo the team.” “My cousin did.” “Well, no true fan would.” The definition shifts to dodge the exception.
The tell: the goalposts move the instant a counterexample appears. Counter: “Define ‘real’ before the example, not after.”
Loaded Question
plurium interrogationum — the trap in the asking
A question that bakes in an unproven assumption, so any direct answer concedes it.
“Have you stopped cutting corners on safety?” Both “yes” and “no” admit you were cutting corners.
The tell: there’s no honest one-word answer. Counter: reject the premise before answering — “That assumes a thing that isn’t true.”
Equivocation
the slippery word
Using one word in two different senses within the same argument, as if it meant the same thing throughout.
“A feather is light; what is light cannot be dark; therefore a feather cannot be dark.” “Light” swaps from weight to brightness.
The tell: a key term quietly changes meaning mid-argument. Counter: “Pin that word down — which sense are we using?”
Family IV — Moving the crowd
Appeal to Popularity
argumentum ad populum — bandwagon
Treating wide belief as proof. That many hold a view says nothing about whether it’s correct.
“Millions can’t be wrong — it must be true.” Millions have been wrong before; headcount isn’t evidence.
The tell: the support is a crowd size, not a reason. Counter: “Popular and true are different questions.”
Appeal to Authority
argumentum ad verecundiam
Treating a figure’s say-so as proof — especially outside their field, or against the weight of evidence. (Citing real expertise in its field isn’t the foul; deferring blindly is.)
“A famous actor endorsed this supplement, so it works.” Fame isn’t pharmacology.
The tell: the credential stands in for the evidence. Counter: “What does the actual data show?”
Appeal to Emotion
argumentum ad passiones
Substituting a feeling — fear, pity, pride, outrage — for a reason. The feeling may be valid; it still isn’t an argument.
“If you really cared, you wouldn’t even ask for the numbers.” Guilt is deployed to stop the question.
The tell: the heat rises exactly where the evidence should be. Counter: “I’m moved — and I still need the case.”
Appeal to Nature
“natural” = good
Assuming what is natural is therefore good or right (and the artificial therefore bad). Nature includes hemlock; factories make insulin.
“It’s all-natural, so it’s safe.” Plenty of natural things are deadly, and plenty of made things save lives.
The tell: “natural” is doing the work of “proven.” Counter: “Natural and safe aren’t the same claim.”
Family V — Bad inference
Slippery Slope
the runaway staircase
Claiming a first step must inevitably cascade to an extreme outcome, with no argument for why each link follows.
“If we allow this one mural, soon every wall in the city will be graffiti.” The chain of “soons” is asserted, never shown.
The tell: a parade of inevitabilities with no mechanism between the steps. Counter: “Show me the link from step one to step ten.”
Post Hoc
post hoc ergo propter hoc — “after, therefore because”
Treating sequence as cause: B followed A, so A caused B. Correlation gets promoted to causation without a mechanism.
“I wore my lucky socks and we won, so the socks won the game.” Two things happened in order; that’s not a cause.
The tell: the only evidence for cause is timing. Counter: “Could anything else explain it? What’s the mechanism?”
Hasty Generalization
the sample of one
Drawing a broad rule from too few cases, or an unrepresentative one.
“Two rude clerks downtown — that whole city is rude.” Two people aren’t a population.
The tell: a sweeping “all/every/always” resting on a handful of cases. Counter: “How big and how representative is the sample?”
Appeal to Ignorance
argumentum ad ignorantiam
Claiming something is true because it hasn’t been proven false (or false because unproven). Absence of evidence is treated as evidence.
“No one’s proven it doesn’t work, so it works.” Not-yet-disproven isn’t the same as shown.
The tell: the gap in knowledge is offered as the proof. Counter: “The burden is on the claim, not on its denial.”
Motte and Bailey
the castle and the field
Advancing a bold, hard-to-defend claim (the bailey); when challenged, retreating to a modest, obvious one (the motte) — then strolling back out to the bold claim once the pressure’s off.
Bold: “This method fixes everything.” Challenged: “I only meant it sometimes helps.” Unchallenged: back to “fixes everything.”
The tell: the claim shrinks under fire and re-inflates after. Counter: “Which claim are you defending — the strong one or the safe one? Pick one.”
The house, on itself
The fouls this museum has to watch 🎩
Naming fouls is easy; not committing them is the work. The ones this site is most exposed to, on the record:
Appeal to emotion — a museum built around a semicolon and a love letter runs hot. Feeling earns a place here; it never gets to replace the argument. The back room is a fire exit, not a mood.
Hasty generalization — “only humans can score” is a claim drawn, so far, from a small self-selected crowd. That’s why the Ticker stays dark until the sample is real. Read the Debate Pass, Claim IV.
Appeal to authority (its own) — “the machine built it, so trust it” is a foul we refuse. The machine poured the concrete; humans decide what hangs and what it’s worth. Proof of Work.
The standing order: run this list on our own copy before we run it on anyone else’s. If we ever commit one of these in public, that’s a card we lose — out loud, in our own words.
The wing stays open — fouls get added as they’re spotted. Calling one on the house is the system working. The Debate Pass · How to play · The Ethos