Logical Fallacies

begging the question

A claim is based on evidence or support that is in doubt. Example: Everyone wants the new iPhone because it is the hottest new gadget on the market!

Weak Analogy

A comparison between two concepts, but the connection between the two isn't strong enough to make a case. Example: Guns are like hammers—they're both tools with metal parts that could be used to kill someone.

Hasty Generalization

A faulty conclusion is reached because of inadequate evidence. Example: Even though it's only the first day, I can tell this is going to be a boring course.

Appeal to Authority

A speaker or writer seeks to persuade not by giving evidence but by appealing to the respect people have for a famous person or institution. Example: A commercial claims that 3 out of 4 dentists would choose this particular brand of toothpaste for their own families to use.

Accident

An error in reasoning caused by sweeping generalizations Example: I believe one should never deliberately hurt another person, that's why I can never be a surgeon.

Appeal to Popularity

Arguing that a claim must be true merely because a substantial number of people believe it. Example: Everyone says that it's okay to lie as long as you don't get caught.

Two wrongs make a right

Arguing that your doing something morally wrong is justified because someone else has done the same (or similar) thing. Example: Jimmy stole Tommy's lunch in the past. Therefore, it is acceptable for Tommy to steal Jimmy's lunch today.

Appeal to Ignorance

Arguing your conclusion is true but there is not evidence against it. Example: There's life in the universe because it hasn't been proven to not exist outside of our solar system or that UFOs have visited Earth.

appeals to pity

Asks for your compassion instead of appealing to your reason Example: Commercials that show starving children in Africa before asking for donations to feed them.

Bandwagon

Assumes that because something is popular, it is therefore good, correct, or desirable. Example: Everyone is going to get the new smart phone when it comes out this weekend.

Appeal to Probability

Assuming because something could happen, it will inevitably happen. Example: I see a dark cloud on the horizon. Dark clouds mean rain. It's going to rain here today.

Ad Hominem

Attacks the person rather than dealing with the real issue in dispute Example: Green Peace's strategies aren't effective because they are all dirty,lazy hippies

Strawman Argument

Distorting somebody's contention to make it simpler to assault Example: We know that evolution is false because we did not evolve from monkeys.

Affirming the Consequent

If A then B B Therefore, A Example: If taxes are lowered, I will have more money to spend. I have more money to spend. Therefore, taxes must have been lowered.

Denying the Antecedent

If P, then Q. Not P. Therefore, not Q. Example: If it barks, it is a dog. It doesn't bark. Therefore, it's not a dog.

Genetic Fallacy

Irrelevance based on someone's or something's history, origin, idea, or character. Example: My parents told me that God exists; therefore, God exists.

Prejudicial Language

Loaded or overly emphasized word choice to believe the proposition. Example: Right thinking Canadians will agree with me that we should have another free vote on capital punishment.

Playing the Victim

Make yourself look like the victim of circumstances. Example: a student who did poorly in a class because of a lack of effort concludes that his grade was the result of racism and tells his parents, they might consider a law suit against the professor

False Dilemma

Offers a limited number of options (usually two) when in fact more options are available. Example: you're either with us or against us

Circular Argument

Restates the argument rather than actually proving it. Example: George bush is a good speaker because he speaks effectively

The Burden of Proof Fallacy

Saying that the burden of proof lies not with the person making the claim, but with someone else to disprove. Example: Lisa believes in ghosts. Mark tells her that there is no evidence that ghosts exist. Lisa tells Mark that there is no evidence that they don't.

Red Herring Fallacy

The introduction of the topic is not related to the subject. Example: I know I forgot to deposit the check into the bank yesterday. But, nothing I do pleases you.

Missing the Point

The premises of an argument do support a particular conclusion—but not the conclusion that the arguer actually draws. Example: There has been an increase in burglary in the area. It must be because there are more people moving into the area.

Tu Quoque

You avoided having to engage with criticism by turning it back on the accuser Example: You should stop smoking. It's harmful to your health.

appeal to tradition

a fallacy which assumes that something old is automatically better than something new Example: The cheerleaders should be allowed to wear their uniforms to school on Fridays because that's the way we have always done it. It is a tradition at this school.

post hoc ergo propter hoc

after this, therefore because of this Example: Every time that rooster crows, the sun comes up. That rooster must be very powerful and important!"

Faulty Appeal to Authority

an appeal to someone who has no special knowledge in the area being discussed Example: A commercial claims that a specific brand of cereal is the best way to start the day because athlete Michael Jordan says that it is what he eats every day for breakfast.

Dicto Simpliciter

assuming that something true in general is true in every possible case Example: Exercise is good. Therefore everybody should exercise.

Appeal to Emotion

described by the control of the beneficiary's feelings so as to win a contention, particularly without verifiable proof. Example: Luke didn't want to eat his sheep's brains with chopped liver and brussel sprouts, but his father told him to think about the poor, starving children in a third world country who weren't fortunate enough to have any food at all.

fallacy of exclusion

evidence which would change the outcome of an inductive argument is excluded from consideration Example: You shouldn't join a frat because they drink like fish.

Equvocation

one meaning in one portion of the argument and then another meaning in another portion of the argument Example: I don't see how you can say you're an ethical person. It's so hard to get you to do anything; your work ethic is so bad

Slippery Slope

proposes that one stage will unavoidably lead to more, inevitably negative steps Example: You can never give anyone a break. If you do, they'll walk all over you.

non sequitur

something that does not logically follow Example: People generally like to walk on the beach. Beaches have sand. Therefore, having sand floors in homes would be a great idea!

Complex Questions

the response to an offered question assumes an earlier response to an earlier inquiry. Example: Have you stopped beating your wife?

Appeal to Fear

when a person attempts to create support for an idea and attempting to increase the fear towards the alternative. Example: If we don't bail out the big automakers, the US economy will collapse. Therefore, we need to bail out the automakers.