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 (fear, pity, outrage, insecurity, etc.)

"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."

Argument against the person (ad hominem)

A personal attack as 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, aka false compromise, aka gray fallacy

This fallacy declares that the middle point between two false extremes must necessarily be true.

Argument from numbers/argument from popularity/argumentum ad populum/bandwagon

This fallacy declares that something must be 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.

Circular argument, aka circulus in demonstrando, aka begging the question

Assuming that which you are trying to prove. "You can't give me a C because I'm an A student." "President Reagan was the Great Communicator because he was a very effective public speaker." "The media should not give coverage to third-party candidates because no one has heard of those candidates before."

Complex question

Any question that presupposes an unproven conclusion. "Where did you hide the money you stole?" "How many times did you cheat on me?" "How do you explain your failed social policies?"

Cum hoc ergo propter hoc

translation, "with this, therefore because of this." The fallacy of thinking that because two 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 two things that cannot fairly 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.

False dichotomy, aka black or white fallacy

Creating a false choice between only two options when there might be more than two 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 a 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" fallacy, aka special pleading

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. Example: "All women are nurturing." "But my mother was cold and distant!" "Then she's not a real woman."

Post hoc ergo propter hoc

translates as "after this, therefore because of this." Along with cum hoc ergo propter hoc, it is the foundation for all superstition, and goes like this: First event A happened, then event B happened. Therefore, A caused B. Example: "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 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. "Mitt Romney wants to destroy Medicaid and turn over our Social Security to Wall Street!"

Sharpshooter fallacy aka cherry-picking aka card-stacking

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

"You too" fallacy/tu quoque/the hypocrisy fallacy

This argument, instead of actually attacking an idea, merely accuses its supporter(s) 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 from the premises or arguments presented.