LSAT 126 | Section 4 | Logical Reasoning: Q23

LR Question 23 Explanation

QUESTION TEXT: Physics professor: Some scientists claim that superheated…

QUESTION TYPE: Sufficient Assumption

CONCLUSION: Superheated plasma with failed electrical resistance is never a factor in causing ball lightning.

REASONING: Every time the professor saw ball lightening, it was not caused by superheated plasma.

ANALYSIS: The professor’s reasoning is not good. He generalizes from his own experience and presumes that all ball lightning is the same.

It is like saying: “Every swan I have seen is white, therefore all swans are white…” Google “black swan bird” to see why this is faulty.*

However, we could save the professor’s reasoning if we presume that all ball lightning has the same cause.

___________

1. This weakens the argument, if anything. We’re trying to prove that it is a cause, a cause of ball lightning at the least.
2. This shows that his testimony is more likely to be accurate, but it doesn’t prove his conclusion.
3. This weakens his argument, as he’s trying to say that the causes he observed are the only causes.
4. This doesn’t allow him to connect his observations to the conclusion that superheated plasma is never a cause.
5. CORRECT. If they all have the same cause, that means his observations are enough to rule out superheated plasma in all cases.

Recap: The question begins with “Physics professor: Some scientists claim that superheated”. It is a Sufficient Assumption question. Learn how to master LSAT Sufficient questions on the LSAT Logical Reasoning question types page.