Tricks
“The sign says Fine for parking here, so I thought it was fine to park here.”
Equivocation. The word fine has two meanings (a penalty vs. “okay”). The argument switches meanings mid-reasoning, hiding the flaw.
“He must be guilty; after all, he committed the crime.”
The premise assumes the point under debate (it presumes guilt rather than proving it).
“If it rains, the picnic will be canceled. The picnic was canceled, so it must have rained.”
Invalid deduction. From “If A then B” and “B”, you cannot validly infer “A” — there could be other reasons the picnic was canceled.
“I met two rude tourists from that country. People from that country are rude.”
Rash Generalization. Uses small sample size to speak for the whole.
“Don’t listen to her argument about recycling — she’s doesn't even have a recycling bin."
“She doesn’t have a college degree, so she’s uneducated.”
Conflation.This treats having a degree and being educated as the same thing when they are different concepts.
“This textbook is correct because the author is an authority, and the author is an authority because the textbook says so.”
Circular Argument
“If you study, you’ll pass. You didn’t study, so you won’t pass.”
Invalid Deduction. From “If A then B” and “not A” you cannot infer “not B”; passing could still happen for other reasons.
“Dogs are friendly, so this aggressive guard dog must be friendly too.”
Sweeping Generalization. A generally true rule (many dogs are friendly) is applied without allowance for exceptions (some dogs are trained/aggressive).
“You can’t tell me not to text while driving. You do it too!”
Counter Attack. The critic’s hypocrisy is used to deflect from the argument’s validity rather than addressing the behavior’s dangers.
Son: But, Dad, I am already very responsible. Whenever something breaks around here, it seems like I am always Responsible.
Equivocation. Confuses the term Responsible.
A granola bar is healthy, because it is full of all natural ingredients.
Begging the Question. It assumes that all natural ingredients automatically make something healthy.
“Ice cream sales and drowning incidents both rise in summer; therefore ice cream causes drowning.”
Casual Flaw. Correlation is mistaken for causation; a third factor (hot weather) explains both rises.
“You either love this teacher or you hate them — no in-between.”
Restriction of Options. There is in fact an inbetween.
“If we let students eat in class once, soon they’ll nap in class, and school will become meaningless.”
Slippery Slope. It predicts a chain of increasingly extreme consequences without showing the causal links that make them likely.
“Support for policy X is the same as support for the politician who suggested it.”
Conflation. It treats support for an idea and support for a person as identical, ignoring that someone might disagree with the person but like the policy (or vice versa).
You can trust what I say, I have never lied a day in my life.
Begs the question. What if he is lying about never lying?
“Ever since the new coach arrived, the team has been winning — the coach must be the reason.”
Casual Flaw. Sequence is taken as proof of cause without showing how the coach produced the wins.
“Oxygen is necessary for fire, thus fire exists only because of oxygen"
“You said we should consider less homework. Clearly, you want students to never study again.”
Strawman. The original moderate position (reduce homework a bit) is distorted into an extreme claim (no studying) so it’s easier to attack.
Achoo! I must have a cold. I better put on a sweater.
Equivocation. Confuses the world Cold (temp) cold (sickness)
Person A: Capital punishment for murder is perfectly justified.
Person B: Why?
Person A: Because it is right for society to put to death those who have committed murder.
Circular Argument. Uses the argument to prove itself.
“Successful entrepreneurs are always risk-takers. Maya takes bold risks every day, so it’s only a matter of time before she becomes a highly successful entrepreneur.”
Invalid Deduction. While risk-taking is a trait of entrepreneurs, not all risk-takers succeed. The conclusion overgeneralizes.
“You must be 18 to vote; Jim is 18 therefore he can vote in the next election."
Confusion of Necessary and Sufficient Conditions. There are many other requirements in order to vote.
“If we approve this small tax increase, soon taxes will double and everyone will be bankrupt.”
Slippery Slope. The argument leaps from a small, specific policy to a catastrophic outcome without evidence the steps will occur.