Questions: Logical Consistency and Internal Contradiction

Question 1

Which of the following is an example of begging the question (circular reasoning)?

• A. All humans are mortal; Socrates is human; therefore Socrates is mortal
• B. Violent media is harmful because consuming it causes harm to viewers
• C. Most professional athletes train daily, so your favorite athlete probably does too
• D. You shouldn't trust her argument — she has a financial interest in the outcome

Answer: (B)

Option B restates the conclusion ('harmful') in the premise ('causes harm') using different words — the argument assumes what it sets out to prove. This is circular reasoning. Option A is a valid syllogism. Option C is an inductive generalization (potentially weak but not circular). Option D is an ad hominem fallacy — a different structural error.

Question 2

A writer argues: 'Studies show one in ten coffee drinkers reported mild anxiety. Therefore, coffee is a public health crisis requiring urgent government intervention.' What logical consistency problem does this argument have?

• A. It uses false premises — the statistic is fabricated
• B. The conclusion exceeds what the premises establish — this is scope inconsistency
• C. It commits equivocation on the word 'anxiety'
• D. The argument is circular because 'crisis' is implicitly assumed in the premise

Answer: (B)

The premise establishes a modest claim: 10% of coffee drinkers experience mild anxiety. The conclusion leaps to 'public health crisis requiring urgent intervention' — far beyond what the evidence supports. This is scope inconsistency: the conclusion has been inflated beyond what the premises can warrant. Readers who notice this gap conclude the writer is overreaching, which undermines credibility even if the statistic is accurate.

Question 3

An argument in which nearly every premise is true is expected to be logically consistent.

• T. True
• F. False

Answer: False

True premises do not guarantee consistency. An argument can have all true premises and still be internally inconsistent if the conclusion exceeds the scope the premises establish, if premises subtly contradict each other, or if a key term shifts meaning between premise and conclusion. Logical consistency is a structural property — about how the parts fit together — distinct from whether the content of the premises is accurate.

Question 4

Equivocation undermines an argument's logical consistency because a key term shifts meaning between premise and conclusion, breaking the logical chain.

• T. True
• F. False

Answer: True

If a term means one thing in a premise and something different in the conclusion, the logical bridge between them is illusory. The classic example: 'Laws of nature cannot be broken; traffic laws are laws; therefore traffic laws cannot be broken.' 'Law' carries two different meanings. The argument appears valid but the equivocation makes the inference fail — you are not actually reasoning from the same claim throughout.

Question 5

What is the difference between an argument that is false and an argument that is internally inconsistent? Provide an example of each.

Model answer: A false argument has at least one false premise — the content is wrong but the structure may be valid. Example: 'All birds can fly; penguins are birds; therefore penguins can fly' — valid structure, false premise. An internally inconsistent argument has parts that contradict each other or a conclusion that outstrips its premises, regardless of whether the premises are true. Example: 'Some politicians are dishonest; therefore no government can ever be trusted' — the conclusion vastly exceeds what the premise establishes.

The distinction matters for how you repair the argument. A false argument needs better evidence or corrected premises. An inconsistent argument needs its structure repaired — either by strengthening premises to actually support the conclusion, or by narrowing the conclusion to what the premises genuinely establish. Diagnosing which problem exists is the first step in any effective argument revision.