Quiz 2: Inductive & Deductive Reasoning and Logical Fallacies

inductive reasoning

A type of reasoning that presents cases or evidence that lead to a logical conclusion.

Example:

Facts or Evidence

1. Our volleyball team won only 2 out of 14 games.

2. Most of the players said they didn’t understand what to do in their positions on the court.

3. Our coach never played volleyball in high school or college.

Conclusion

• We need to get a new, experienced volleyball coach.

deductive reasoning

A type of reasoning that constructs general propositions that are supported with evidence or cases.

Example:

General statement:

• Politicians who give money to people to vote for them are dishonest.

Evidence/specific cases:

• Our mayor pays people to vote for him.

• Our mayor is dishonest.

fallacy

Evidence or reasoning that is false or in error.

ad hominem

When someone calls you “stupid” or insults you instead of responding to your argument, he or she has dodged/avoided the issue or topic.

circular reasoning/begging the question

When someone says the same thing they have already said but using different words. (avoiding the issue)

• Example:

  “Hats in schools should be prohibited because hats are not allowed in schools.”

evading the issue

When someone gives reasons that don’t actually support the main idea being argued. (avoiding the issue)

• Example:

  “Our football coach should be replaced. Our baseball coach is great.”

oversimplification

Omit or leave out key ideas in an argument.

• Example:

  “Fast-food restaurants are the cause of the obesity epidemic in America.”

overgeneralization

Omit key points. (hint words: never, always, totally, completely)

• Example:

  “My mother never understands me!”

either/or

Argue a point and not present all the options. Gives you just two choices, leaving out all other possible choices that may solve the problem. (Ignore other alternatives)

• Example:

  “You either get your homework done now or you won’t get it done at all.”

slippery-slope

Argument that suggests that one thing WILL lead to something else, when in reality it may not. (ignore other alternatives)

• Example:

  “If I let Adam eat a brownie, I’ll have to let your other brothers and sisters have anything they want.”

false cause

Ignoring the real cause of something by saying that something causes something when it really doesn’t. (ignore other alternatives)

• Example:

  “The water overflowed the bathtub because the TV was on.”

false analogy

Offering a comparison that doesn’t make sense. (ignore other alternatives)

• Example:

  “My father can’t make up his mind. He’s like a teenager.”

false authority

Using an expert who is NOT an expert in the topic being discussed to prove their point. (ignore other alternatives)

• Example:

  “‘Japan’s killing of whales makes the ocean cleaner,’ reported Rufus Rockhead, Ph.D. in geology.”

  • (Rufus Rockhead is not an expert in whales or the ocean.)