Fallacies in ReasoningFallacies in Reasoning

Patterns of incorrect reasoning Patterns of incorrect reasoning

Appeal to A Questionable Appeal to A Questionable AuthorityAuthority Example: Using sports figures to Example: Using sports figures to

endorse productsendorse products

Jumping to ConclusionsJumping to Conclusions

A hasty generalization A hasty generalization Example: One college student does not Example: One college student does not

pay back a loan. The bank manager pay back a loan. The bank manager concludes that students are poor risks concludes that students are poor risks for loans.for loans.

Making GeneralizationsMaking Generalizations

Assume all members of the group are Assume all members of the group are the samethe same

Example: All lawyers are greedy.Example: All lawyers are greedy.

Attacking the Person Attacking the Person

We attack the person rather than We attack the person rather than discussing the issuediscussing the issue

Example: Attacking the President to Example: Attacking the President to sidetrack the issuessidetrack the issues

Appeal to Common BeliefAppeal to Common Belief

Just because it is common belief does Just because it is common belief does not make it truenot make it true

Example: At one time people believed Example: At one time people believed that the world was flatthat the world was flat

Common PracticeCommon Practice

If everyone does it, it must be OKIf everyone does it, it must be OK Example: It’s OK to cheat on your Example: It’s OK to cheat on your

taxes. Everyone else does.taxes. Everyone else does.

Appeal to TraditionAppeal to Tradition

We’ve always done it that wayWe’ve always done it that way Example: Some jobs are only for men Example: Some jobs are only for men

and others only for womenand others only for women

Two WrongsTwo Wrongs It is OK to do something wrong because It is OK to do something wrong because

other people do itother people do it Example: Someone cuts you off on the Example: Someone cuts you off on the

freeway so you pull in front and cut freeway so you pull in front and cut them off them off

Slippery SlopeSlippery Slope

Dire consequencesDire consequences Example: If you fail this class, you are a Example: If you fail this class, you are a

failure for lifefailure for life

Wishful ThinkingWishful Thinking

An extremely positive outcome is An extremely positive outcome is proposed to distract from logicproposed to distract from logic

Example: Get rich quick schemesExample: Get rich quick schemes

Beware of ScamsBeware of Scams

It’s too good to be trueIt’s too good to be true There is a rush to make a decisionThere is a rush to make a decision You have to pay money or give your You have to pay money or give your

credit card number credit card number High pressure, time limitsHigh pressure, time limits Prizes and big promisesPrizes and big promises The word “free”The word “free”

Critical Thinking Over the Critical Thinking Over the InternetInternet Beware of appearances.Beware of appearances. What is the source?What is the source? Why was the information posted?Why was the information posted? What is the date of the Web site?What is the date of the Web site? Can the information be verified Can the information be verified

elsewhere?elsewhere?

Appeal to Fear or Scare Appeal to Fear or Scare TacticsTactics Emotions interfere with rational thinkingEmotions interfere with rational thinking Example: Political advertisements that Example: Political advertisements that

describe dire consequences describe dire consequences

Appeal to PityAppeal to Pity

Again, emotions replace logicAgain, emotions replace logic Example: Sob storyExample: Sob story

Appeal to LoyaltyAppeal to Loyalty

Group behavior, right or wrongGroup behavior, right or wrong Example: Voting for the candidate who Example: Voting for the candidate who

appears most popularappears most popular

Appeal to PrejudiceAppeal to Prejudice

A stereotype in which all members of a A stereotype in which all members of a group are judged to be the samegroup are judged to be the same

Example: Racial prejudicesExample: Racial prejudices

Appeal to VanityAppeal to Vanity

Making complimentsMaking compliments Example: “Apple polishing”Example: “Apple polishing”

Post Hoc Reasoning or False Post Hoc Reasoning or False CausesCauses Cause and effect are not relatedCause and effect are not related Example: SuperstitionsExample: Superstitions

Straw Men or WomenStraw Men or Women Create an image of someone Create an image of someone

else, like a scarecrow, to else, like a scarecrow, to discredit the persondiscredit the person

Example: Political speeches Example: Political speeches which paint the opponent in an which paint the opponent in an unfavorable lightunfavorable light

Cult BehaviorCult Behavior

Beliefs for which hard evidence is Beliefs for which hard evidence is lackinglacking

Example: Cults such as Heaven’s GateExample: Cults such as Heaven’s Gate The opposite of critical thinkingThe opposite of critical thinking Blindly following a charismatic leaderBlindly following a charismatic leader Belonging to a group Belonging to a group