Logical Fallacies

What is a Fallacy?

According to Webster’s Dictionary, a fallacy is an error in reasoning or a flawed argument.

It’s an argument that does not conform to the rules of logic, but appears to be sound.

Prevalence of Fallacies in Advertising

Fallacies are all around you… Advertisements in magazines, on T.V.,

on billboards all contain fallacies!

Can you think of a place where there are NO advertisements? Probably not! That’s because

advertising is impossible to escape and ad-free zones rarely exist.

Impact of Fallacies

What might be the impact of being told that we are not pretty, handsome, rich, clean, or good enough?

What does the casual acceptance of surrounding ourselves with fallacies say about us?

Types of Fallacies: Ad Hominem

Ad Hominem (meaning “against the person”) attacks the person and not the issue

The major difficulty with labeling a piece of reasoning as an ad hominem fallacy is deciding whether the personal attack is relevant.

Example: Ad Hominem

Types of Fallacies: Traditional Wisdom

Traditional Wisdom uses the logic that the way things used to be is better than they are now, ignoring any problems of the past.

If you say or imply that a practice must be okay today simply because it has been the apparently wise practice in the past, you commit the fallacy of traditional wisdom.

Types of Fallacies: Bandwagon

Bandwagon creates the impression that everybody is doing it and so should you.

If you suggest that someone’s claim is correct simply because it’s what most everyone is coming to believe, then you’re committing the bandwagon fallacy.

Example: Bandwagon

Types of Fallacies: False Dilemma

False dilemma limits the possible choices to avoid consideration of another choice.

A person who unfairly presents too few choices and then implies that a choice must be made among this short menu of choices commits the false dilemma fallacy.

Example: False Dilemma

There are some things money can’t buy. For everything else, there’s MasterCard.

Types of Fallacies: Scare Tactic

Scare tactics create fear in people as evidence to support a claim.

While fear may be a reasonable reaction to certain facts, your argument should not rely on fear in order to be persuasive. Are all appeals to pathos fallacious?

Scare Tactics (Fear Appeal)

The streets of our country are in turmoil. The universities are filled with students rebelling and rioting. Communists are seeking to destroy our country. Russia is threatening us with her might, and the Republic is in danger. Yes—danger from within and without. We need law and order! Without it our nation cannot survive.

--Adolf Hitler, 1932

Types of Fallacies: False Cause

False Cause wrongly assumes a cause and effect relationship.

Improperly concluding that one thing is a cause of another Example: My psychic adviser says to expect

bad things when Mars is aligned with Jupiter. Tomorrow Mars will be aligned with Jupiter. So, if a dog were to bite me tomorrow, it would be because of the alignment of Mars with Jupiter.

False Cause Example

Post Hoc Ergo Propter Hoc “After this, therefore because of this” It started raining outside when the

band began to play. Therefore, the band caused it to rain!

Types of Fallacies: Red Herring

Red herring presents an irrelevant topic to divert attention away from the original issue.

A Red Herring is actually a smelly fish that would distract even a bloodhound, so in the case of advertisements…it causes the viewer to become so distracted that they forget about the true issue at hand.

Types of Fallacies: Hasty Generalization

Hasty generalization (or jumping to conclusions) draws a conclusion about a population based on a small sample. Example: I’ve met two people in

Nicaragua so far, and they were both nice to me. So, all people I will meet in Nicaragua will be nice to me.

Types of Fallacies: Slippery Slope

Suppose someone claims that a first step (in a chain of causes and effects, or a chain of reasoning) will probably lead to a second step that in turn will probably lead to another step and so on until a final step ends in trouble. If the likelihood of the trouble occurring is exaggerated, the slippery slope fallacy is committed.

Slippery Slope Example

Mom: Those look like bags under your eyes. Are you getting enough sleep?

Jeff: I had a test and stayed up late studying. Mom: You didn’t take any drugs, did you? Jeff: Just caffeine in my coffee, like I always do. Mom: Jeff! You know what happens when people

take drugs! Pretty soon the caffeine won’t be strong enough. Then you will take something stronger, maybe someone’s diet pill. Then, something even stronger. Eventually, you will be doing cocaine. Then you will be a crack addict! So, don’t drink that coffee.

Types of Fallacies: False Authority

While some testimonials and appeals to ethos are credible, the validity of the argument depends on the source Example: A professional athlete may be

able to recommend a good athletic shoe. However, I wouldn’t automatically trust their recommendation for President.

Others…

Non Sequitur The conclusion doesn’t follow from the

evidence Circular Reasoning

Your claim is actually your evidence! You can trust me because I would never

lie to you! Name Calling Glittering Generalities

Video: Examples

The Fallacy Project Post Hoc Ergo Propter Hoc

Applying What You Learned:

You will now be working in small groups to identify the types of fallacies used in several different advertisements.

As a group, you will need to come to an agreement as to which type of fallacy is being used in each advertisement.

You will write your answers on the “Finding the Fallacies that Surround You” Hand-out

Example 1:

Example 2:

Example 3:

Example 4:

Example 5:

Example 6:

Works Cited

Information taken from: http://www.readwritethink.org The Internet Encyclopedia of

Philosophy: Fallacies

Poster Assignment

Poster Assignment

Create a poster that a person in Hawaii, Puerto Rico, or the Philippines might have used to protest American involvement in their country in the early 1900s.

Color, Phrases, Visually Appealing One logical fallacy and other

rhetorical strategies