QUESTION TEXT: John of Worcester, an English monk, recorded…
QUESTION TYPE: Strengthen
CONCLUSION: The Korean aurora borealis helps confirm that John of Worcester saw sunspots.
REASONING: Sunspots typically produce an aurora borealis, after five days. Koreans observed an aurora borealis five days after John of Worcester claimed he saw sunspots.
ANALYSIS: This seems like a good argument. There is no horrendous flaw. The conclusion is appropriately mild: it just says the Korean sighting helps confirm John’s claim.
To strengthen the argument, we can simply make the confirmation stronger. As things stand, it’s possible that some other element caused the aurora borealis. The right answer shows that only sunspots could have caused the aurora.
- This weakens the claim by showing the aurora borealis might have occurred even if John’s sighting was false.
- Nonsense. The argument didn’t claim John was the first person to see sun spots. The author just said John did see sunspots, so it doesn’t matter who else saw them on a previous occasion.
- CORRECT. This virtually guarantees the conclusion. It eliminates the possibility that the aurora borealis had another cause. Therefore there was heavy sunspot activity on the day that John of Worcester claimed to have seen sunspots.
- This weakens the argument, by adding necessary conditions to John of Worcester’s claim. We don’t know if John met these necessary conditions.
- This is just a neat fact. We’re trying to prove that John did see sunspots. These illustrations don’t prove anything. In fact, if John didn’t see sunspots, then these illustrations are false.
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