9 most common logical fallacies

8/12/2019 9 Most Common Logical Fallacies

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Recognizing LogicalFallacies

A logical fallacy is a mistake inlogical thinking; it is a MENTAL

TRAP


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Looking at the Negative Space

We can learn muchabout logic by studyingthat which is notlogical examples ofwhere logic breaksdown, logical fallacies.


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1. Over-generalization Drawing too wide a conclusion from

the given facts Example:

All kids cause trouble. Timmy is a kid. Therefore, Timmy causes trouble.

Fix this by recognizing qualifiers

(many, few, some, all, etc.)


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2. Arguing in Circles Def: Supporting an opinion not with evidence but with

the same opinion, slightly disguised (restating theargument in different words). Using the word youredefining in the definition is a classic example.

Example: Education is important for kids, so they should get

an education. Everybody likes ice cream because it is liked by all.

Belligerently means in a belligerent way.

Fix it by making sure you are giving support,not just repeating the idea. Never use the

word youre defining in the definition.


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3. Black & White Thinking

Def. An opinion that claims there are onlytwo alternatives (when there might be more)

Examples: Youre either for it or against it. Are you a jock or a nerd?

Fix this by remembering that the world is acomplicated place and that on most issuesthere are many alternatives.


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4. Red Herring Def. Presenting an irrelevant topic to divert

attention away from the original issue. Also known as Ad hominem: getting

personal as you discredit someone. Examples:

What do you know? Youre just a kid. I got an F. Mr. X hates me.

Fix this by staying focused on the topic;watch out for those who dont.


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5. Loaded Questions and

Statements Def. A question or a statement that

conceals an opinion or assumption.

Examples: Do you still beat your dog? You dont think that, do you?

All intelligent people agree that

Fix this by listening carefully andseparating fact from opinion.


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6. Statistical Fallacies

& False Authority Def. People usually believe in numbers and expertswithout questioning them. Here statistics are used tomisrepresent rather than describe.

Examples: 3 out of 4 dentists prefer Crest. (Did Crest pick the dentists?) I surveyed 100 people and they all agreed with me. (I chose my

friends). Dr. X says this is the fastest and safest way to lose weight. (Did

he/she get paid? Where do they practice?)Fix this by analyzing the evidence. Where did the support come

from? Is there self interest involved? Did you get the wholepicture?


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7. Faulty Causal Relationship

(also called Post Hoc) Def. To excuse an action or belief by making it sound

sensible. Often this assumes that anything that came

before an event caused it to happen. Example:

I stole the towel from the hotel. They expect people to takethem.

Eating 5 energy bars and drinking 2 Cokes helps me get bettergrades. I did this and got an A on my history test.

Fix this by examining the relationship between ideas.Make sure the facts precede the theory and the reasons

precede and cause the belief.


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8. Misleading Comparison Def. Mistakenly believing that two

situations or people can be compared. Examples:

Jill looks good in red. Ill buy red pants, too. Forcing students to read books is like herding

cattle to slaughter. You gave him extra time on the test, so I should

get extra time too. Saddam Hussien is Hitler.

Fix this by remembering that every person

and situation has different circumstances .


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9. Bandwagon

Def. Lots of people do this, so you should,too.

Examples: Adults are smoking, so it is ok to do so. The American people do not stand for . . .

Fix this by making decisions based on facts,not popularity.

9 most common logical fallacies

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