Logical Fallacy

Definition

• A pitfall in logic. Something that seems to be logical but, upon deeper examination, is not.

Different Types

• Arguing in a circle

• Weak analogy

• Attacking the person

• Presumed cause and effect

• Slippery slope

• Two wrongs

• False dilemma

Different Types

• Hasty generalization

• Misuse of statistics

• Bandwagon approach

• Snob appeal

• Questionable authority

Arguing in a circle• When you use repetition as proof

“Why do you

drink?”

“To forget”

“Forget what?”

“That I’m sad.”

“Sad about what?”

“That I drink so much!”

Weak Analogy

• An assumption that just because two things are similar in one way, they are similar in others.

“My brother is a boy, and he picks his nose. So this boy here must pick his nose, too!”

Attacking the Person (Ad Hominem)

• Commenting on the person (appearance, family history, race, religion, ethnicity), not what they say or do

Presumed Cause and Effect

• Drawing a conclusion that one thing led to another without much evidence

Slippery Slope

• Presuming a number of different effects that may not happen

Two Wrongs

• The attempt to defend a behaviour by noting that others also behave that way

• “So what if Rob Ford

smokes crack? Justin

Trudeau’s done pot!”

False Dilemma

• Misrepresenting a situation by saying there are only two possible positions (either or)

Hasty Generalization

• Making sweeping generalizations based on little evidence

Misuse of Statistics

• Presenting stats in a biased way

Bandwagon Approach

• Exploiting the desire to be part of the crowd

Snob Appeal

• Convincing people they’ll be able to join an elite group

Appeal to Questionable Authority

• Unjustifiably claiming that people in power accept your argument when they have no known reason to do so.