Logical Fallacies

anecdotal argument

using a single story from someone’s personal experience to make a broad generalization. Example: “Welfare is a huge waste of money because of cheating. One time I was at the grocery store and saw a guy buy beer with food stamps.”

appeal to authority

using the support of a famous person or authority figure to argue in favor of something. “Albert Einstein was against war.” The famous person or authority figure may not be qualified to judge the particular topic.

appeal to nature

any argument that something is good because it is natural, or bad because it is unnatural. By this logic, rape is good and surgery is bad.

appeal to personal incredulity

this fallacy occurs when Y states that X cannot possibly be true because Y can’t understand or believe it.

appeal to emotions

“This is bad because it’s sad".” Or because it’s outrageous. Or because it’s disgusting. Attempts to provoke rather than persuade.

appeal to tradition

“We should do this because we’ve always done this,” or “We should not do this because we’ve never done it that way before.”

ad hominem

a personal attack as a substitute for argument; attacking the opponent personally instead of attacking the opponent’s argument.

argument from ignorance

an argument that attempts to fill gaps in knowledge with a specific idea: in other words, my position is true because it is not known to be false. Or, “since no one can prove that I am wrong, therefore I am right.”

argument to middle ground

this fallacy declares that the middle point between two false extremes must necessarily be true. "Person A says the sky is blue, Person B says it's yellow, so let's agree it's green". 

argument from numbers/bandwagon

this fallacy declares that something must me true if a lot of people believe it is true, or that something is false if a majority of people do not agree with it.

argument from repetition

simply repeating a proposition over and over again, usually changing the language slightly. “This is wrong because it is immoral. It is immoral because it is not right. It is not right because it is unethical.” etc.

burden of proof fallacy

asserting that critics or skeptics are responsible for disproving claims, instead of the person actually making the claim. “I argue X because there is nothing proving non-X.”

circular argument

assuming that which you are trying to prove. “You can’t give me a C because I’m an A student.” “Alex is a cheerful person because he’s always in a good mood.”

complex question

any question that presupposes an unproven conclusion; asks a question that assumes the answer to another question. “Where did you hide the money you stole?” “How many times did you cheat on me?” “How do you explain your failed social principles?”

cum hoc ergo propter hoc

translates to “with this, therefore because of this”; thinking that because 2 things happened at the same time, one caused the other. “I crossed my fingers when I rolled the dice, that’s why I won the bet.”

false analogy

comparing 2 things that cannot be compared. It often takes the form: (1) A and B are similar. (2) A has a certain characteristic. (3) Therefore, B has that characteristic too. “Snow is white. That bird is white. Because these things are alike, that bird is also cold like snow.”

false dichotomy

creating a false choice between only 2 options when there might be more than 2 options in reality. “If you don’t support the war, then you support the terrorists.”

guilt by association/genetic fallacy

this argument takes the form “A bad/evil person supports idea A; therefore idea A is wrong/bad/evil.” It attempts to transfer the negative feelings about the bad person to an idea without actually criticizing the idea itself.

naturalistic fallacy

this argument presumes that the current state of affairs is the correct state of affairs. “There are more men than women in the Senate, therefore men are meant to dominate in the Senate.”

no true scotsman

when terms are redefined to suit your argument and exclude all exceptions that disprove your argument. It’s a method of reinterpreting evidence in order to prevent refutation and produce an unfalsifiable premise. “All women are nurturing.” “But my mother was cold and distant!” “Then she’s not a real woman.”

post hoc ergo propter hoc

translates to “after this, therefore because of this”; along with cum hoc ergo propter hoc, it is the foundation of all superstition: First event A happened, then event B happened. Therefore, A caused B. “After I performed a pagan rain dance, there was a thunderstorm; therefore my rain dance caused the storm.”

slippery slope

compresses an entire chain of cause and effect into a single unbroken ramp of consequences. The argument falsely assumes that first action A will inevitably lead to final result G while bypassing the actual consequences, effects, and decisions of B, C, D, E, and F that come in between. “If you smoke pot once, you’ll become a homeless drug addict.” “If you fail math class, you’ll never get into a good college.”

straw man

constructing a false, flawed version of your opponent’s argument so that you may more easily attack it; distorts their opponent's argument by exaggerating or oversimplifying it. “Fruits and veggies are good for you.” “Are you trying to force everyone to be vegetarian?”

cherry-picking

carefully selecting information that favors your argument (or that discredits your opponent's argument) while deliberately ignoring the rest.

tu quoque/you too fallacy

this argument, instead of actually attacking an idea, merely accuses its supporters of hypocrisy. The supporter says “Action A is morally wrong” and the opponent responds “No it isn’t—you yourself have engaged in Action A!” But Action A has not been criticized at all.

non-sequitur

“does not follow”; a statement doesn’t logically follow what came before it. "People generally like to walk on the beach. Beaches have sand. Therefore, having sand floors in homes would be a great idea!".