LNAT Evaluating Argument Strengths 3 — Questions and Answers
Question 1: An editorial argues: 'We should not listen to Dr. Smith's views on climate change because she once worked for an oil company.' Which flaw does this commit?
- Hasty generalization
- Ad hominem (Correct answer)
- False dilemma
- Circular reasoning
Correct answer: Ad hominem
Dismissing an argument based on the speaker's background rather than the argument's content is an ad hominem fallacy.
Question 2: Which of the following is an example of a valid deductive argument?
- Most politicians are corrupt; therefore this politician is corrupt
- All mammals breathe air; whales are mammals; therefore whales breathe air (Correct answer)
- Crime has risen recently, so society is getting worse
- The economy improved after the tax cut, so the tax cut helped the economy
Correct answer: All mammals breathe air; whales are mammals; therefore whales breathe air
This syllogism is valid because if the premises are true, the conclusion must follow necessarily.
Question 3: A lawyer argues: 'My client must be innocent because the prosecution has not proven guilt beyond reasonable doubt.' Is this argument sound in the legal context?
- No, because lack of proof does not establish innocence
- Yes, because the legal standard requires the prosecution to bear the burden of proof (Correct answer)
- No, because reasonable doubt is subjective
- Yes, because all defendants are presumed guilty until proven otherwise
Correct answer: Yes, because the legal standard requires the prosecution to bear the burden of proof
In criminal law, the prosecution bears the burden of proof; failing to meet that standard legally justifies acquittal.
Question 4: An argument uses the following structure: 'Either you support this policy or you don't care about children.' This is an example of which fallacy?
- Slippery slope
- False dichotomy (Correct answer)
- Bandwagon appeal
- Begging the question
Correct answer: False dichotomy
The false dichotomy presents only two options when many intermediate or alternative positions exist.
Question 5: Which of the following would most strengthen an argument that a new drug reduces hospital readmission rates?
- Doctors prefer prescribing the drug because it is easy to administer
- A randomized controlled trial showed significantly lower readmission in the drug group versus placebo (Correct answer)
- Patients who took the drug reported higher satisfaction scores
- The drug has fewer side effects than older alternatives
Correct answer: A randomized controlled trial showed significantly lower readmission in the drug group versus placebo
A randomized controlled trial with a placebo group provides the strongest causal evidence for the drug's effectiveness.
Question 6: Argument: 'Thousands of people cannot be wrong—this restaurant must be excellent.' Which flaw is present?
- Circular reasoning
- Appeal to popularity (Correct answer)
- Hasty generalization
- Appeal to authority
Correct answer: Appeal to popularity
An appeal to popularity assumes that widespread belief or practice validates a claim, which is logically insufficient.
Question 7: In evaluating an argument's strength, what does 'cogency' require for an inductive argument?
- The conclusion must be logically necessary given the premises
- The argument must be strong and all premises must be true (Correct answer)
- The argument must use statistical evidence
- The premises must be accepted by a majority of experts
Correct answer: The argument must be strong and all premises must be true
A cogent inductive argument is both inductively strong (premises make conclusion likely) and has all true premises.
LNAT Evaluating Argument Strengths 3
An editorial argues: 'We should not listen to Dr.
Smith's views on climate change because she once worked for an oil company.' Which flaw does this commit?