Logical Fallacies
Common errors in reasoning that undermine the logic of your argument
Slippery Slope
If A happens than B, C, D... X, Y, Z will happen
Hasty Generalization
A conclusion based on insufficient or biased evidence
post hoc ergo propter hoc
If A occurs after B then B must have caused A Correlation=causation
Genetic fallacy
the origins of a person, idea, institute, or theory determine its character, nature, or worth
Begging the Claim
The conclusion that the writer should prove is validated within the claim.
Circular Argument
Restates the argument instead of proving it
Either/or
oversimplifies the argument by reducing it to only two sides or choices
Ad hominem
An attack on the person rather than on the opponent's ideas.
ad populum/bandwagon
an appeal that presents what most people, or a group of people think, in order to persuade one to think the same way
Red herring
a diversionary tactic that avoids the key issues, often by avoiding opposing arguments rather than addressing them
Straw man
It oversimplifies an opponents argument and then attacks that hollow argument
Moral Equivalence
Comparing minor misdeeds with major atrocities, implying they are the same
Tu Quoque
When someone avoids the argument and attacks the other person, "No you are!"
Equivocation
Writer shifts the meaning of a word that then shifts the argument
reductio ad absurdum
Showing someone the inevitable conclusion of a thought in order to make it look ridiculous
No True Scotsman
Shifting the goalpost or definition so that no example is acceptable
Middle-Ground Fallacy
Presenting two extremes and assuming that a compromise is the correct course of action
Texas Sharpshooter Fallacy
Finding a pattern where none exists, or changing the conclusion to fit the evidence
The Fallacy Fallacy
Tossing out someone's argument because it contains a fallacy
Ex: Slippery Slope
If you don't take honors courses, you won't get into a good college.
Ex: Hasty Generalization
Jack met a few people with red hair in his life, but he thought they were all mean. Jack now believes all redheads are mean and no longer associates with them.
Ex: post hoc ergo propter hoc
Crime rates increased after people started playing video games, so video games are responsible for the increased crime rates.
Ex: genetic fallacy
I can't believe anything my doctor says about my health issues, he is overweight himself!
Ex: Begging the claim
Water bottles are bad for the environment because they're bad for nature
Ex: Circular argument
You must obey the law, because it's illegal to break the law.
Ex: either/or
You either support praying in public schools or you're an atheist
Ex: Ad Hominem
Steve thinks Earth is flat, so who knows what other crazy stuff he believes?
Ex: ad populum/bandwagon
Everyone drives over the speed limit, so it should not be against the law.
Ex: Red herring
Why are you pulling me over for speeding? Shouldn't you be out catching the real criminals? Someone could be robbing a bank as we speak!
Ex: straw man
A Democrat politician says he wants to spend more money on the social safety net. His Republican opponents call him a communist.
Ex: Moral Equivalence
Cars kill people just like guns. Therefore, if we ban either one of them, we should ban the other too
Ex: Tu Quoque
Parent: "You have to clean your room, it's too messy." Child: "But your room is messy too, so why should I listen to you?"
Ex: Equivocation
Noisy children are a real headache. Two aspirin will make a headache go away. Therefore, two aspirin will make noisy children go away.
Ex: reductio ad absurdum
If you were the unhappiest person in the world then you would probably die from sadness. You are still here so you cannot be that unhappy.
Ex: No True Scotsman
John doesn't drink alcohol. No real man avoids alcohol. John isn't a real man.
Ex: middle ground fallacy
Joe says the sky is pink and Liz says the sky is blue, so they should really just compromise and say the sky is purple.
Ex: Texas Sharpshooter fallacy
A recent study showed that the top 10 countries where Italian soda is most commonly consumed are also countries that have some of the lowest rankings in reported cases of depression. Therefore Italian soda makes people happy
Ex: fallacy fallacy
Jenna thinks we should do yoga before work because it is natural and is said to relax you. Miles thinks we should also smoke pot before work for the same reasons