Logical Reasoning

PT135 · S4 · Q24 Paleomycologists, scientists who study

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Paleomycologists, scientists who study ancient forms of fungi, are invariably acquainted with the scholarly publications of all other paleomycologists.

Evidence

Paleomycologists always know P → know SP's the scholarly publications of of other P's all other paleomycologists.

Professor M knows the M knows SP of D. scholarly publication of D is a P. Professor D, who is a paleomycologist.

Conclusion

Professor M must be M is a P. a paleomycologist.

Evaluation

Like a lot of Parallel Flaw arguments, this one commits a Necessary vs. Sufficient flaw, reading a conditional backwards.

If Professor M is a paleo, then he would definitely know the SP of Professor D.

We know that Professor M knows the SP of Professor D, but that doesn't prove Professor M is a paleo. We can't read that rule backwards and think .

Goal

The flaw was presenting a conditional "X --> Y" and then reasoning that if someone is Y, then they must be X. The other details are extraneous.

24.

The flawed pattern of reasoning in the argument above is most similar to that in which one of the following arguments?

  1. Correct

    When a flight on Global

    Why this is right

    This also commits a backwards logic flaw. We know that "If a GA flight is delayed, then connecting GA flights will be delayed". The argument then reasons right to left by saying, "Since F's connecting GA flight was delayed, we know that her first flight was a delayed GA flight."

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

    70% picked this

  2. Any time that one of

    Trap

    Weaker Premise / Conclusion Match Illegal Negation vs. Reversal Confusingly, this is also committing a Necessary vs. Sufficient flaw. However, this one looks less similar to the original, because this one performs a negation, rather than a reversal. Logically, the flaw in this argument is pretty equivalent to the flaw in (A). But as a "pattern", a reversal feels different from a negation. Original: paleo → acquainted with X. Joe is acquainted with X. Thus, Joe is a paleo. choice (B) someone misses → work harder Last week no one missed. Thus, last week not work harder.

    3% picked this

  3. Any time the price of

    Bad Evidence Match

    The premise actually triggers the left side of the conditional. Since fuel has decreased several times, several times GA's expenses have gone down while revenue has been unaffected. The effect of each of those decreases was to increase GA's profitability. We still wouldn't be able to prove they made a profit, but it's not like the original flaw. In the original, the premise established the right side of the conditional.

    2% picked this

  4. All employees of Global Airlines

    Different Flaw (Possible vs. Certain)

    Here the conditional is been with company 1+ yrs → can be in retire plan As soon as we see the Premise is validly triggering the left side of the conditional (Gavin has been with company for 1+ yrs), we know this doesn't match the original. The flaw with this conclusion, for what it's worth, is that we only know by triggering that conditional that Gavin can be in the retirement plan. We don't know for sure he is.

    19% picked this

  5. Whenever a competitor of Global

    Bad Contrapositive vs. Reversal

    As soon as we see the factual premise is saying something that goes against the right side of the conditional, we know this doesn't match the original argument (whose factual premise matched the right side of conditional). This attempts to argue (validly) by contrapositive, but it messes up the fact that the trigger of the contrapositive has two conditions that must be obtained. This answer argues, since "X --> Y or Z" and "~Z", then "~X". But ~Z is not enough on its own to prove ~X; you also need to know ~Y. The conditional says, competitor GA also GA loses reduces → reduces or passengers fairs fairs By contrapositive, ~Lose ~Reduce Competitors Passengers and fares → ~reduce fares

    5% picked this

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