Logical Reasoning

PT106 · S3 · Q16 Historian: We can learn about the

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Historian: We can learn about the medical history of individuals through chemical analysis of their hair.

Conclusion

If we find a trace of mercury in Beethoven's hair, we'll know that venereal disease caused Beethoven's deafness.

Evidence

In Beethoven's time, mercury was commonly ingested to treat venereal disease.

Evaluate

This actually has the structural feel of a Necessary vs. Sufficient flaw. We know that in Beethoven's time that .

The author is thinking,

We know that venereal disease was one possible reason why you would have mercury in your system, but maybe it's not the only reason. Maybe Beethoven used a mercury-laden shampoo on his hair. Maybe he put mercury on his oatmeal. Maybe mercury was also the treatment for heart disease or lung disease.

Maybe mercury was the cure-all Robitussin of its day (this is an allusion to a Chris Rock comedy routine).

Goal

The author is assuming there isn't some other explanation for why people would have mercury in their hair, and the author is assuming anything needed to make his explanation plausible (Beethoven would have realized he had a disease, gone to a doctor, been prescribed mercury, taken the prescribed meds, etc.).

16.

Which one of the following is an assumption on which the historian's argument depends?

  1. None of the mercury introduced

    Too Strong: none

    The author doesn't need to assume that once mercury is in your body, not one atom of it can be eliminated. If we negate this, we get a weak idea like "at least one bit of mercury can be eliminated from the body". That won't be any sort of objection. It won't affect the author's argument if 1% of the mercury we ingest gets eliminated over time. She is only looking for "a trace" of mercury, so she even seems cognizant that most of the mercury may be gone by this point, but a trace may remain.

    23% picked this

  2. Correct

    Some people in Beethoven’s time

    Why this is right

    This is really weak language, which is appealing, because when we negate it, it turns into a strong idea. The negation of "some (at least one)" is "none". If we said "No people in B's time did not ingest mercury", we'd have a double negative. Clean it up, and we're saying "Every single person in B's time ingested mercury". Okay, this ruins the author's argument. If everyone ingested mercury, then finding a trace of mercury wouldn't reveal that you had venereal disease (unless 100% of people also had venereal disease). It wouldn't be possible to differentiate between the people who had mercury for their VD and people who ingested mercury for other reasons.

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

    42% picked this

  3. Mercury is an effective treatment

    Out of Scope: effective

    The author doesn't need to assume that these outdated medical treatments were effective. We can mention that "people used to use leeches to suck out their evil thoughts"; that doesn't mean we're assuming that "leeches are an effective way to remove evil thoughts".

    6% picked this

  4. Mercury poisoning can cause deafness

    Out of Scope: mercury caused deafness

    The author was saying that venereal disease caused deafness, not mercury. The VD caused deafness. The mercury was prescribed as a treatment for the VD. They say that mercury poisoning may have caused Newton's psychological problems, but at no point is the author suggesting that mercury caused Beethoven's deafness.

    27% picked this

  5. Beethoven suffered from psychological problems

    Too Strong

    "Same" is a sneaky extreme word. If you replaced it with "identical" it would properly scare you. The author doesn't need to assume that B's psychological problems are identical in severity to N's. In fact, the author doesn't need to assume that Beethoven has any psychological problems. Deafness is a physiological problem, not a psychological problem.

    2% picked this

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