Logic and Scientific Thinking

Recap

Question	Answer from Session 7
The three-step diagnosis?	Name the move · quote the words · say what would decide it
Faulty reasoning?	False cause · circular reasoning
Misused sources?	Ad hominem · appeal to authority

Two families down — two to go: distorted claims and emotional appeals.

Today’s Route

Today: distorted claims and emotional appeals — plus one neighbor (the verbal dispute) and the volume tactic.

Faulty reasoningMisused sourcesDistorted claimsEmotional appeals

1false cause

2circular reasoning

3ad hominem

4appeal to authority

5straw man

6red herring

7slippery slope

8equivocation

9false dilemma

10appeal to fear

11appeal to pity

12bandwagon

∞Gish Gallopthe volume tactic — carries any move above; felt previouslymeta

Straw Man

“S1: I’d rather not get a dog.”
“S2: So you hate animals?”

S2 rebuilt S1’s claim
S2 likely wants to attack S1
Test: would the opponent accept your summary of their view?

The Ice Cream Swap (2005)

The Kid’s claim, before you watch — the only thing he asserts: chocolate is the best.

Listen for the one sentence where that claim gets swapped.

Nobody Said Chocolate

The move	The line
1. The claim	Kid: “Chocolate is the best.” = Among other flavors, I prefer chocolate.
2. The rebuild	Dad: “So it’s ALL chocolate for you?” = Among other foods, you would always choose chocolate
3. The attack	Dad: a speech on freedom, choice, liberty. = You are against choice and thus, liberty
4. The original claim	I prefer chocolate

One word swapped:
- “best” became “all”; that’s the whole trick.

Nobody Said Chocolate

The move	The line
1. The claim	Kid: “Chocolate is the best.”
2. The rebuild	Dad: “So it’s ALL chocolate for you?”
3. The attack	Dad: a speech on freedom, choice, liberty.
4. The original claim	Never addressed — still unanswered.

Test: would the Kid accept the following representation of the his argument?

“you’re against choice”?
No → straw man.

Red Herring

A committee is deciding whether to renew the scholarship program for another year.

“Q: Does it actually raise graduation rates?”
“A: Do you know how hard these students worked to get here?”

The reply changes the subject — the question is never answered.
The diversion is true, and pressing on now feels heartless.
Straw man rebuilds the claim; red herring abandons it.
Test: is the reply still about the original question?

NARRATION: Second move in the same family. Set the scene first, in one breath — a committee has to decide whether the scholarship runs again next year, so somebody has to answer the question before the money moves. That context is what makes the evasion cost something; without a decision riding on it, changing the subject is merely rude. The question was whether the program raises graduation rates. The reply is about how hard the students worked. Nothing was rebuilt this time — the subject was simply swapped. Now here is what makes a red herring effective, and it is not what people expect. Everything in that reply is TRUE. The students did work hard. That is exactly why it works: the diversion is not a lie you can catch, it is a true statement that makes going back to the original question feel cold. Ask the room what it costs to say “yes, and I am still asking about the graduation rates” — they will feel the social pressure immediately, and that pressure IS the fallacy doing its job. The defect is not falsehood, it is irrelevance. So the test is one line: is the reply still about the question that was asked?

Slippery Slope

“Fail this one exam, then never graduate, and never get a job.”

One step is claimed to make the catastrophe inevitable
The earlier chain caution: every link is another premise
- ten steps, ten chances to be wrong.
Demand the middle: how exactly does A lead to Z?

“Don’t Wake Up in a Roadside Ditch” (2012)

An entire slippery slope in 30 seconds: - Count the arrows - Which one is ever argued?

Seven Arrows, Zero Arguments

ON HOLD → angry → blow off steam → accident → eye patch → “tough” → challenged → DITCH

Each single step is slightly plausible
- the chain is absurd.
The ad is honest comedy:
- at seven arrows, everyone sees it

Test: “How exactly does an eye patch lead to a ditch?”

Equivocation

P1.	Mice are mammals.
P2.	The thing next to my laptop is a mouse.
C.	The thing next to my laptop is a mammal. ✗

In P1, mouse = the animal.
In P2, mouse = the gadget.
The word changed meaning between premises

Equivocation

The serious version — the same switch, with real stakes:

P1.	In science, evolution is a theory.
P2.	A theory is just a guess.
C.	So evolution is just a guess. ✗

In P1, theory = a tested explanatory framework.
In P2, theory = a hunch.
The word changed meaning between premises.

The test: same word? — make sure it’s the same meaning, start to finish.

Equivocation vs. Verbal Dispute

Same starting point — one word, two meanings. Different situations:

	Equivocation	Verbal dispute
The two meanings	both inside one argument	one per side
The word is used…	inconsistently — it switches between premises	consistently — each side keeps its own meaning
What’s broken	the argument — the conclusion needed one meaning throughout	only the appearance of disagreement
The cure	same meaning, start to finish	ask: “what do you mean by ___?”

Talking Past Each Other

“S1: She’s successful — she earns a fortune.”
“S2: She’s not successful — she’s miserable.”

S1 means: successful = rich.
S2 means: successful = happy.
Swap the definitions in:
- S1: “She’s rich.”
- S2: “She’s unhappy.”
Likely both S1 and S2 agree

Talking Past Each Other

“S1: She’s successful — she earns a fortune.”
“S2: She’s not successful — she’s miserable.”

The fix: ask “what do you mean by success?”

“Is a Hot Dog a Sandwich?” — The Late Show (2017)

Two definitions, one word: - “meat between bread” vs. - “you’d cut it in half.”

One Word, Two Definitions

	Colbert	Hodgman
The claim	“A hot dog IS a sandwich.”	“A hot dog is NOT a sandwich.”
His definition	sandwich = meat between bread	sandwich = a thing you’d cut in half
By his own definition…	right	right

Ask yourself: what fact about hot dogs do they disagree on?
- None
Each is right by his own definition
- there is no factual disagreement.

The Hidden Question

“S1: Using AI to write your essay is cheating — you didn’t do the work.”
“S2: It’s not cheating — it’s a tool, like a calculator or a spell-checker.”

S1 means:
- “your own work” = you wrote every word.
S2 means:
- “your own work” = you made it — tools allowed.

The Hidden Question

“S1: Using AI to write your essay is cheating — you didn’t do the work.”
“S2: It’s not cheating — it’s a tool, like a calculator or a spell-checker.”

Swap the definitions in:
- by S1’s definition, it is cheating.
- by S2’s definition, it isn’t.

Both are consistent — so part of this fight is just the word.
- but only part.

The Hidden Question

“S1: Using AI to write your essay is cheating — you didn’t do the work.”
“S2: It’s not cheating — it’s a tool, like a calculator or a spell-checker.”

The real question:
- where is the line?
- calculator → spell-checker → Google → AI outline → full AI draft
Most people accept the calculator; most courses reject the unedited AI draft.
The real disagreement is somewhere in between — and arguing about where is a real debate, where agreement becomes possible.

The Hidden Question

“S1: Using AI to write your essay is cheating — you didn’t do the work.”
“S2: It’s not cheating — it’s a tool, like a calculator or a spell-checker.”

With charged words — cheating · tool · your own work:

Pick the definition, and the verdict follows: — “punish it” / “allow it.”
Different definitions become different normative claims.

The full lesson: defining the term removes the fake disagreement — and exposes the real one: what is school for?

False Dilemma

“S1: Either we close the border — or we lose the country.”

One skeleton: [my policy] — or [catastrophe].
The catastrophe is asserted, never argued.
Only two options offered when more exist.

False Dilemma

“S1: Either we close the border — or we lose the country.”

The fix: ask “is that everything?”
- the hidden middle: visas, quotas, asylum rules, work permits…
Name a third option, and the “or” collapses.

Emotional Appeals

“We shouldn’t be so restrictive about migration — think of all those mothers separated from their children.”

Appeal to pity — the quote above: a heartbreaking case offered as sufficient to decide the whole policy question.
Appeal to fear — the reply from the other side: “Open the borders, and crime floods your streets.”
Bandwagon — “Most countries adopted lockdown measures — so, we should do the same.”
- (appeal to the emotion of the multitude — but also readable as an appeal to popular authority)

Emotional Appeals

“We shouldn’t be so restrictive about migration — think of all those mothers separated from their children.”

The tell:

in each, one feeling is the whole case
fear and pity pull in opposite directions
a feeling alone can’t decide either way.

NARRATION: Be careful here, because this is the easiest slide in the course to misread. The suffering in that quote is real, and it is relevant. Consequences for people’s rights and dignity belong in a policy argument. The fallacy is never that an emotion appeared. The fallacy is one feeling offered as the whole case, standing in for a proportionate look at the evidence. Now notice something. Fear and pity here pull in opposite directions on the very same question. The same machinery sells either conclusion, which proves a feeling alone cannot decide it in either direction. Bandwagon has a different tell: it names no consequence at all. It just hands your judgement to the crowd. That is why the line under it gives two readings. The classical name is ad populum, an appeal to the emotion of the multitude, which is why it sits in this family. But “many believe it, so it is true” is the same inference as “an expert says it, so it is true” with the crowd in the expert’s chair — which is why the rhetoric session picks it up again as ethos rather than pathos. Both readings are defensible; say so, and tell them the exam only ever asks for the NAME, never the family.

Diagnosing Emotional Appeals

Demo case:

“Open the borders, and crime floods your streets.”

Name the move → appeal to fear (scare tactics).
Quote the exact words → “crime floods your streets.”
Say what would decide it → what do crime data on migrants actually show?

The Gish Gallop

Not one broken argument — too many to check.

Bury the point under a flood of weak claims, faster than anyone can answer.
Every claim left unanswered reads as a point scored.
A tactic, not a fallacy — it can carry any move on the map, or none.

Drill: Name That Fallacy

“I ate cereal before the exam and got an A. Cereal before exams gives you A’s.”
“Don’t trust Luis’s math solution — he failed English.”
“I think we should eat less meat.” — “So you want everyone to be vegan? Ridiculous.”
“Stars produce their own light. Shakira is a star. So Shakira glows in the dark.”
“Professor, I studied all night — you can’t fail me.”
“The bridge inspector found deep cracks. She warns: don’t drive across.”

The Answer Bank

Your options:

Faulty reasoning	false cause · circular reasoning
Misused sources	ad hominem · appeal to authority
Distorted claims	straw man · red herring · slippery slope · equivocation · false dilemma
Emotional appeals	appeal to fear · appeal to pity · bandwagon

Careful: one item isn’t a fallacy at all.

Drill — Answers

1. “I ate cereal before the exam and got an A. Cereal before exams gives you A’s.” Faulty reasoning → FALSE CAUSE (recap) — “after” is not “because.” Decide it: grades with and without cereal.

2. “Don’t trust Luis’s math solution — he failed English.” Misused sources → AD HOMINEM (recap) — English grades are irrelevant to the math; the solution is never checked.

3. “I think we should eat less meat.” — “So you want everyone to be vegan? Ridiculous.” Distorted claims → STRAW MAN — “less meat” rebuilt as “everyone vegan,” then mocked. Would the speaker accept that summary? No.

4. “Stars produce their own light. Shakira is a star. So Shakira glows in the dark.” Distorted claims → EQUIVOCATION — “star” switches meaning between premises: celebrity vs. celestial body.

5. “Professor, I studied all night — you can’t fail me.” Emotional appeals → APPEAL TO PITY — the effort is real and may deserve sympathy, but it is not evidence the answers were right.

6. “The bridge inspector found deep cracks. She warns: don’t drive across.” NO FALLACY. A documented risk, an expert in exactly her field, evidence you could check: legitimate fear, legitimate authority. Crying “scare tactics!” here would itself be the error.

One of the six has no label — and that is the lesson. “Every item must have a fallacy” is itself the mistake.

The Same-Claim Test

A genuine refutation must contradict the same claim (Aristotle, Sophistical Refutations):

Same…	Ask
Meaning	are the key words used in the same sense?
Subject	the same person, group, population?
Outcome	the same result being measured?
Comparison	against the same baseline?
Time	during the same period?

Claim: “The policy reduced violent crime in 2025.” — Reply: “But burglaries rose in one district in March.” Both can be true; nothing was refuted.

The speaker changes one coordinate — and hopes nobody notices.

The Fallacy Fallacy

“Your argument for the curfew is a slippery slope. So the curfew is useless.” ✗

Showing an argument invalid does not show its conclusion false.
A true conclusion can come from a bad argument.
Labels are diagnostic tools, not refutations.
Real arguments may fit several labels — or none cleanly.

The label only starts the work.
What decides it: the evidence

Conclusion

Name the move, quote the words, say what would decide it.

Distorted claims — straw man, red herring, slippery slope, equivocation, false dilemma.
Talking past each other — one word, two definitions; define the term first.
Emotional appeals — fear, pity, bandwagon: a feeling where the evidence should be.
The Gish gallop — too many claims to check: a tactic, analyzed after the midterm.
The fallacy fallacy — naming the move never proves the conclusion false.

References

Schopenhauer, A. (c. 1831/1896). The art of controversy (T. B. Saunders, Trans.). Swan Sonnenschein.
Aristotle. On Sophistical Refutations. (any scholarly edition)

Logic and Scientific Thinking

Act III: Distortion and Emotional Appeals

Recap

Today’s Route

Straw Man

The Ice Cream Swap (2005)

Nobody Said Chocolate

Nobody Said Chocolate

Red Herring

Slippery Slope

“Don’t Wake Up in a Roadside Ditch” (2012)

Seven Arrows, Zero Arguments

Equivocation

Equivocation

Equivocation vs. Verbal Dispute

Talking Past Each Other

Talking Past Each Other

“Is a Hot Dog a Sandwich?” — The Late Show (2017)

One Word, Two Definitions

The Hidden Question

The Hidden Question

The Hidden Question

The Hidden Question

False Dilemma

False Dilemma

Emotional Appeals

Emotional Appeals

Diagnosing Emotional Appeals

The Gish Gallop

Drill: Name That Fallacy

The Answer Bank

Drill — Answers

The Same-Claim Test

The Fallacy Fallacy

Conclusion

References