Week 3: Flaw (LR) Flashcards
Flaw Questions
question stem is asking you to find the inherent flaw / reasoning error in an arg.
Flaw questions take place at the intersection of…
Weaken, Nec. Assumption, and Method questions.
Each of these different question types kind of give us a flaw question to answer.
How to Spot a Flaw Questions: Language Cues
“_____________ to criticism”
- …“on the grounds that it takes for ___________” –> That signals you’re dealing with an ______________ that should be expressed in the answer choice.
“____________ of reasoning”
“which one of the following explain how the reasoning is ____________.”
vulnerable
granted; assumption
error
flawed
3 Ways in which you can think of Flaw Question answer choices
Assumptions
- “Takes for granted that” / “presumes”
Objections
- “fails to consider”
- “neglects”
- “ignores”
Abstract Description
- “concludes”
- “infers X on the basis of Y”
How to Solve
Same as you would all questions in the Assumption Family: Nec. Assumption, Suff. Assumption, Flaw, Strengthen, Weaken
- Find Conclusion
- Find Evidence (for why the conclusion is true)
- remember, in all assumption family question types, the evidence never supports the conclusion. There’s a gap.
- Evaluate
- grant that evidence is true
- ask, “do I have to accept the AC as true?”
- remember, the point of flaw questions is usually to object to the reasoning of the arg.
- Anticipate
- Answer
10 (15) Flaw that you need to MEMORIZE
- Necessary v. Sufficient
- Causal
- Unproven v. Proven False
- Sampling
- Ad Hominem
- Part v. Whole
- Inappropriate Appeals
- Circular Reasoning
- Internal Contradiction
- Equivocation (Ambiguity of Terms)
- Relative v. Absolute [Numbers v. Percentages]
- False Dichotomy (Choice)
- Irrelevant Response
- Overlap Errors
- Intent v. Outcome
- [Strawman Fallacy]
- Necessary v. Sufficient
“Confuses a sufficient condition with a necessary condition.”
to understand necessary v. sufficient flaws, you have to recognize that (invalid) conditional logic is being used.
If A –> Then B
Mistaken Negation
- A –> B, ~A… therefore ~B.
Mistaken Reversal
- A –> B, B… therefore A.
Conditional Logic Language Cues
Divided up into 4 categories (2 Sufficient, 2 Necessary)
Conditions
- if, when, whenever, any, all, every, people who, in order to, the only
Universals
- all / no, each, every, any
Guarantees
- ensures, implies, will, leads to
Requirements
- then, only if, only, must, requires/(ed to), depends, necessitates, unless, until, except, without.
- Causal Flaws
When evaluating a causal argument, we need to ask…
- are there any other other possible explanations? (other possibilities)
- how plausible is the author’s explanation? (plausibility)
Generally in Flaw questions with causal reasoning structure, you’re really want to find whether or not there are other possible explanations.
Types of Causal Flaws
- Inferring causation from mere correlation.
- Inferring causation from sequence of events.
- third factor that caused x and y.
- Reverse Cause: stated cause is actually effect, and stated effect is actually cause.
- Alternate Cause
- Unproven / Proven False
- taking the lack of evidence suggesting the truth of a claim to prove that the claim is false.
- taking the lack of evidence suggesting the falsity of a claim to prove that the claim is true.
- taking some (at lst. 1) evidence suggesting truth of a claim to prove that the claim is true.
- taking some (at lst. 1) evidence suggesting falsity of a claim to prove that the claim is false.
- Part v. Whole
Composition Fallacy
- Assuming what’s true of the constituent parts is true of the whole.
- e.g. this brick is light. Therefore the wall made up of these bricks must be light.
Division Fallacy
- Assuming what’s true of the whole is true of the constituent parts.
- e.g. this brick wall is heavy. Therefore the bricks making up this wall must be heavy.
- Sampling Error
Making a broad generalization based on unrepresentative, AND / OR bias data.
- “I asked everyone in my fantasy basketball league what their favorite spot is and they said basketball. So clearly, basketball is the most popular sport in the nation.”
- we would argue this is a bias sample.
Seems to be overlap between part v. whole and sampling error. What’s the difference?
Basically, the difference is that the generalization in part v. whole errors are internal to group.
Sampling Error:
- Assumes that what’s true of one person is true of all other people like them.
- I got short-changed at that store. Therefore everybody who goes to that store gets short-changed.
Part v. Whole
- Assumes that what’s true of each member is true of the whole.
- Each member of the club went to Europe, therefore, the club went to Europe.
- Ad Hominem
Attacking someone’s motives/character/beliefs instead of the argument they put forth.
Rejecting an argument based on one’s character/beliefs.
- Appeal Fallacies
Appeal to Emotion
- Appealing to sympathy instead of using reasoned claims to make argument.
Appeal to Majority / Numbers
- The majority of ppl say it’s true, therefore it must be true.
Appeal to Authority
- reliance on wrong expertise/wrong authority.
- using the claim of an learned authority figure to establish the truth of your claim.
- Circular Reasoning
Conclusion supports evidence as much as evidence supports conclusion.
Conclusion is a restatement of the evidence, conclusion presupposes the truth of the evidence.
- Internal Contradiction
Making one statement, and saying something else that contradicts the first statement.
e.g. Everyone should join our golf club. It’s really exclusive, and has nice benefits.
- Equivocation
aka, ambiguity of a term.
equates a different meanings of a certain term.
e.g. divorce contract said I have to give half of my money to the ex-wife. But, I doubt the government would allow me to give paper bills sawed in half to my former spouse.
- Relative v. Absolute
Inferring an absolute conclusion from a relative comparison.
e.g.
- The Eiffel Tower is shorter than the Empire State Building.
- Therefore, the Eiffel Tower is short.
- False Dichotomy
When the author assumes there’s only two possible alternatives /choices, when (realistically), there could be more than two.
- Irrelevant Response
supporting conclusion with evidence that is wholly irrelevant.
“People are wrong to say that the Bulls were the best NBA team in the 90’s, because many NFL teams were even more popular.”
- Overlap Errors
most A’s are C’s
&
most B’s are C’s
…
therefore, most A’s are B’s.
Most NBA players practice dunking. Most people who practice dunking are in highschool. Therefore, most NBA players are in highschool.
- Intent v. Outcome
Infers from the outcome of an event, that the event was intended to facilitate that outcome.
Most gamers started playing NBA videogames since the league shut down. This shut-down, therefore, was meant to boost video game sales.
Reasoning Structures
Comparison (71%: most common)
Causation (28%: second most common)
Conditional Logic (23%: least common)
Wrong Answer Choices
SCOPE:
- Out of Scope (Irrelevant)
LOGIC:
- Strengthen
- if the arg. “fails to consider” a certain idea, then it’s supposed then the correct answer will say what they failed to consider, weakening the argument. Strengthening does the opposite work.
- Irrelevant Relationship
- Wrong Flaw
- Not a Flaw
DEGREE:
- Too Strong (AC commits to an idea stronger than what the stimulus says)
- Too Weak (AC isn’t strong enough to impact argument).
