20 terms

"Terrible Twenty" Logical Fallacies

Regardless of context and medium, this list of twenty logical fallacies helps you read (comprehend and analyze and evaluate) faulty logic and avoid writing (applying and creating) faulty conclusions/theses/claims.

Terms in this set (...)

false analogy
Faulty comparison between people, places, or things (concrete and abstract) that lack a strong similarity

Faulty logic: Premises are incomparable, so analogy is inaccurate

Fallacy example: "People are like iguanas; they respond to great speeches."
Denial or failure to recognize a situation's complexity.

Faulty logic: Denies complexity of circumstance by oversimplifying the situation's potential solutions or conclusions.

Fallacy example: "Education today isn't as good as it used to be. Obviously, students don't like to learn."
either-or fallacy
Situation reduced to only two potential solutions or conclusions when more alternatives are possible.

Faulty logic: Excludes alternative conclusions

Fallacy example: "Either we must ban people that don't agree with us from having equal rights to marriage laws, or else all moral values in this country will collapse."
faulty generalization
Conclusion made with inadequate evidence.

Faulty logic: This faulty inductive reasoning, coming in the form of "A and B are true, so all others must be true," mistakes overlap for inclusion.

Fallacy example: "Ducks and geese migrate south for the winter; therefore, all birds migrate south for the winter."
slippery slope
Faulty claim that a relatively small first event will cause or caused a chain of events that end with some significant effect.

Faulty logic: This faulty inductive reasoning, coming in the form of "A and B will lead to Z," is problematic because the conclusion (Z) does not follow directly from the analyzed elements (A and B).

Fallacy example: "He was in a car accident. You will get in a car accident if you accept a ride home from him."
false causation
Analysis of a past situation that mistakes the situation's chronological order of events as cause-and-effect reasons for the situation's outcome.

Faulty logic: Conclusion is not a necessary deduction just because one event happened before another. "A happened and then B happened, so A must have caused B."

Fallacy example: "First, Professor G became my teacher. Then I got better at analyzing logical fallacies. My progress is because of Professor G."
appeal to ignorance
Argument relies on logic that if something can't reasonably be proven true, it must be false; or, if something can't be proven false, it must be true.

Faulty logic: Premises are unknown and cannot reasonably be proven.

Fallacy example: "You can't prove there isn't a Loch Ness monster. It exists!"
bandwagon fallacy
Conclusion is based on popularity instead of sound logic. This implies the pressure that everyone else believes it or does it, so you should also. (AKA: Appeal to Popularity)

Faulty logic: Just because something is popular doesn't mean it's the best answer.

Fallacy example: "Smoking is a healthy and worthwhile pastime because millions of people do it."
double standard
Situation that unreasonably calls special consideration for one side's point-of-view, but not for the other's.

Faulty logic: Evidence judged by different standards; often, one side uses the double standard to deny the validity of inconvenient arguments.

Fallacy example: "The professional athlete should be granted a path to citizenship over a regular person because people want the athlete to be an American."
Argument that's invalid because the conclusion does not come from its premises.

Faulty logic: The conclusion could be either true or false, but the argument is faulty because there is a disconnection between the premises and the conclusion.

Fallacy example: "He lives in a large building, so his apartment must be large as well."
circular reasoning
Argument that assumes what it's attempting to prove.

Faulty logic: Because both the premise and conclusion are essentially the same, the train of logic is circular and invalid.

Fallacy example: "I'm the best painter in the world because I'm a genius!"
false appeal to authority
Abusing a person, place, or thing by misrepresenting its ethos or by over-relying on its ethos instead of providing strong logos.

Faulty logic: Proof isn't based on reputation alone; premises may be untrue.

Fallacy example: "Why am I right? Because I'm you teacher; that's why."
character attack
Attacking the individual instead of the individual's idea.

Faulty logic: Evades giving strong logos by attacking another's ethos.

Fallacy example: "Her opinions on abortion are irrelevant because she's not a mother..."
guilt by association
Attacking the individual's affiliations instead of the individual's idea (a form of personal attack).

Faulty logic: Conclusion does not follow from premise.

Fallacy example: "Ponyboy hangs out with the Greasers. Don't trust a word he says."
poisoning the well
Attacking the opposition's logical response to an argument before the opposition has a chance to respond.

Faulty logic: Opposing premises disqualified prematurely.

Fallacy example: "She cheated on her last boyfriend, so don't listen to anything she tells you. She has to be lying."
red herring
Irrelevant issue used to distract audience from a more important topic."

Faulty logic: Premise has nothing to do with conclusion.

Fallacy example: "We need to place a higher priority on education, so it's clear that you should vote for me."
loaded language
Biased, exaggerated, and/or unnecessary use of emotional word choice.

Faulty logic: Emotional diction (word choice) displaces logic and potentially severs ethos connection with offended audience members.

Fallacy example: "That NAZI security guard told me I have to have a school I.D. to be on campus."
straw man
Argument creates a negative "straw man" image of an opposing argument, individual, and/or group by misrepresenting evidence to sway audience perception.

Faulty logic: Premises are untrue and this form of character attack can backfire, hurting attacking author's ethos appeal.

Fallacy example: "People who favor gun control laws just want to take the guns out of the hands of responsible citizens and put them into the hands of criminals."
false flattery
Argument that relies on positive pathos appeal, often to manipulate audience through false or exaggerated flattery.

Faulty logic: False positive pathos appeal displaces logic.

Fallacy example: "Professor G! I dig your U2 t-shirt. I too like U2. Anyway, I had a lot of things go on last night. Can I have an extra day to turn in the homework?"
appeal to force
Argument that relies on negative pathos appeal, often by threatening audience with negative consequences.

Faulty logic: Negative emotion replaces logic, persuading through negative pathos appeal.

Fallacy example: "Anyone who votes for my opponent may have a hard time evading water balloon projectiles in the parking lot."