Logical Fallacies

What is a logical fallacy?

A fallacy is an error of reasoning. These are flawed statements that often sound true

Logical fallacies are often used to strengthen an argument, but if the reader detects them the argument can backfire, and damage the writer’s credibility

Origins

The word “fallacy” may derive from the Latin word fallere meaning, “to deceive, to trip, to lead into error or to trick.” The word may also derive from the Greek phelos, meaning “deceitful.”

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Why study logical fallacies?

It is important to develop logical fallacy detection skills in your own writing, as well as others’.

Think of this as “intellectual kung-fu: the art of intellectual self defense.” (Logical Fallacies Handlist)

Logical Fallacies and Appeals

Arguments that sound valid and reasonable until they are studied and analyzed.

Celebrity Appeal Other Names:

Sex appeal- does not have to be a celebrity

Transfer Definition: Using a celebrity

or celebrity’s name as the sole proof of your point.

Example: Taylor Swift drinks milk, so it must be the best drink ever!

Traditional Appeal Definition: Trying to prove your

point by saying that people always believed in something particular.

Example: People have used CD’s for the last 15 years. Why should we change to downloading music?

Bandwagon Appeal Definition: Trying to prove

something by suggesting that everyone is doing it.

Example: Everyone is going to the party! I’ll be the only one NOT there! or

Everybody breaks the speed limit. Why should I have to slow down?

Emotional Appeal

Definition: Appealing to people’s prejudice's or emotions.

Example: If you donate money you’ll save this one-eyed, 3 legged puppy’s life (insert sappy music here).

Flag Waving Definition: Appealing to

people’s feelings of patriotism.

Example: Anyone who doesn’t support the war effort is unAmerican

Inadequate proof Definition: Giving too few

instances to prove your point Example: Marie ate at Taco

Bell today. It must be her favorite place to eat.

Attacking the Source Other Names:

Name calling Mud slinging

Definition: Praising or blaming the source of your proof, and then ignoring the idea.

Example: He’s a liberal; therefore he’s a terrible teacher.

Circular Reasoning Definition: Attempting to

prove something by repeatedly stating the point

Example: “All of us cannot be famous, because all of us cannot be well known.” Jesse Jackson

Unreliable Authority Definition: Using an

unqualified and unreliable source to support an idea.

Example: My mom says that if we were to go to war, we would win easily.

Faulty Example Definition: Making a

weak or untrue comparison.

Example: My boyfriend is tall so he must be a great basketball player.

Irrelevant conclusion Definition: Drawing

conclusions that do not follow from previous information.

Example: The house across the street is for sale. The owners must have lost all their money gambling.

Guilt/ Innocence by Association Definition: Trying to prove guilt or

innocence by associations with good or bad things.

Example: Those kids all wear black clothes and hang out after 9 o’clock at night. They must all have parole officers! or

Mr. Doe can’t be a child molester; he’s a Sunday school teacher and a boys’ soccer coach.

Overgeneralization Definition: Letting

one fact stand as the basis for a broad conclusion.

Example: Because the aliens in Avatar are blue, all aliens must be blue.

False Cause Definition: Trying to prove that

because something occurred after an event that thing is a result of the event.

Example: It was raining the day I failed my test. Therefore, my failure was due to the weather.

Either –OR- Fallacy

Definition: Stating your proof in either-or terms, excluding all other possibilities.

Example: Either she’s pretty or she has a nice personality. She can’t have both.

Need for Objectivity Definition: It’s important not

to ignore information that contradicts your point.

Example: Smoking can’t be bad for us, because no tobacco company has ever been found guilty of wrongful death.