LSAT 141 | Section 2 | Logical Reasoning: Q5

LR Question 5 Explanation

QUESTION TEXT: Science writer: Lemaitre argued that the universe began…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Lemaitre’s theory is not correct.

REASONING: Both Lemaitre’s theory and another theory are consistent with observations.

ANALYSIS: I’ll give an example. Suppose I say “I think the box is full of lead” and someone else says “I think the box is full of iron”.

We pick up the box. It’s heavy. That’s consistent with both theories. Either theory could be right, so it’s wrong to say “the box can’t be full of lead because a competing theory is consistent with the facts”. Both theories have an equal amount of support, so they can’t be used as evidence against each other.

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1. The argument doesn’t talk about the person behind the other theory. Their expertise isn’t relevant. The only thing that matters is that their theory is also consistent with observation.
2. What term? And how did it shift in meaning? You need to be very precise to pick this sort of answer. I don’t see that any term shifted.
3. The author didn’t assume causation.
   Example of flaw: The light went off, and there was a noise. Therefore, the light caused the noise.
4. CORRECT. Both theories predicted the data. Since they both have equal support, we can’t use Lemaitre’s theory to prove the other theory wrong. It could also be the case that the other theory is right and Lemaitre’s is wrong.
5. The author didn’t say that only the two theories in question could be right. They just said Lemaitre’s wasn’t right.
   Example of flaw: Both theories could be right. Therefore, they’re the only possible theories.