LSAT 106 | Section 3 | Logical Reasoning: Q16

LR Question 16 Explanation

QUESTION TEXT: Historian: We can learn about the medical history of…

QUESTION TYPE: Necessary Assumption

CONCLUSION: If we find mercury in Beethoven’s hair, then it’s true he had a venereal disease.

REASONING: In Beethoven’s era, people often took mercury to cure venereal diseases. And some have suggested Beethoven became deaf because of a venereal disease.

ANALYSIS: This is a bad argument. First, there might have been other reasons why people took mercury, apart from venereal disease.

Second, Beethoven might have ingested mercury, even if he didn’t consciously take any. There was more mercury back then.

Third, it’s possible that Beethoven took mercury because he thought he had a venereal disease (even though he didn’t have one).

The correct answer points out another assumption: we’re assuming that some people did not consume mercury. If everyone did, then we won’t learn anything about Beethoven. He was just following the crowd.

___________

1. The argument isn’t hurt if the body can eliminate some mercury. It’s only necessary that enough mercury stays behind that we can find it in the hair.
    
   (Actually, even that isn’t necessary. The argument only said what would be true if we found mercury. It didn’t say lack of mercury would prove Beethoven was free of VDs.)
2. CORRECT. If everyone ingested mercury, then finding mercury in Beethoven’s hair can’t possibly prove anything.
3. It doesn’t matter whether mercury worked. We only care why Beethoven took it (many people take false cures).
4. This would weaken the argument. The author argued that venereal disease caused the deafness, not mercury poisoning.
5. The author didn’t claim that mercury caused Beethoven to suffer psychologically. Mercury is just supposed to be evidence of venereal disease.