Logical Reasoning

PT23 · S3 · Q18 If the recording now playing on

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If the recording now playing on the jazz program is really “Louis Armstrong recorded in concert in 1989,” as the announcer said, then Louis Armstrong was playing some of the best jazz of his career years after his death.

Conclusion

The announcer must have gotten the date of the recording wrong. (i.e. the recording on the radio was not Louis Armstrong in 1989)

Evidence

The recording was definitely Louis Armstrong. Louis Armstrong died years before 1989.

Evaluate

Looks like the structure we're looking for is something like P1: If X were true, then that would mean Y. P2: But Y is impossible. Conc: So X must be false.

There's a sneaky extra dimension in here that I would find challenging to formalize. There are two parts to the name of recording: Louis Armstrong, and 1989. We know the recording was wrong. Was it wrong because it wasn't Louis or wasn't 1989?

The author gives us a premise affirming that it definitely was Louis, forcing the error to be the date.

Goal

If the answer preserves that "ruling out one option to conclude another" aspect, then it will probably feel a little more like this:

Prem1: If X and Y are true, then something impossible would be true. Prem2: X was definitely true. Conc: So, Y must not have been true.

18.

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

The museum is reported as
Bad Premise Match
This feels pretty close at first, until we read some other options. We want to know that a claim is impossible, leaving us with two possible reasons for why it's wrong. Then we want a premise to rule out one of those options and a conclusion that settles on the other. To make this match the original argument more, we'd need something like, If the museum really acquired a painting by Hoffman, then [a sculptor who never made paintings would have made a painting]. Since we know the museum did acquire a painting, it must not be by Hoffman. The last two ideas could have also been: Since we know the acquisition was by Hoffman, it must not have been a painting.
8% picked this
This painting titled La Toilette
Weak Premise Match
The first sentence could be fine, but the "Since" premise is off. It's spelling out the impossibility of the outcome in the conditional. But the original argument didn't do that. It didn't say "Since Louis Armstrong couldn't have played his best jazz while dead, the announcer must have gotten the date wrong." The "Since" premise is supposed to be ruling out one way of resolving the error.
20% picked this
Correct
Only if a twentieth-century Mexican
Why this is right
"Only if" = necessary, right side condition Prem1: If this work is really the 17th century Japanese landscape it seems to be and designed by Frida Kahlo as it is labeled, then a 20th century Mexican artist painted in Japan during the 17th century. Prem2: Since [this is a 17th century Japanese landscape] Conc: The label is wrong (it's not by Frida) This gives a conditional with an impossible outcome (telling us the trigger can't be true). Then there's a premise ruling out one way of explaining how the trigger could be wrong, and a conclusion that provides the other way of explaining how the trigger could be wrong.
Skill tested: Parallel · how this choice captures the argument's function is the move to repeat next time.
52% picked this
Unless Käthe Kollwitz was both
Bad Premise Match
This doesn't have a conditional with an impossible outcome. It's definitely possible that Kollwitz was both a sculptor and a printmaker. The fact that she's known for her prints doesn't resolve that question in any way.
4% picked this
If this painting is a
Weak Premise Match
This doesn't provide a conditional with an impossible outcome. It's highly possible that this painting wasn't done by Elisabeth V.L. Thus, there's no validity to saying the painting must not be acrylic. It could be an acrylic portrait that wasn't done by Elisabeth.
18% picked this

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