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#32471
Complete Question Explanation

Flaw in the Reasoning—SN. The correct answer choice is (C)

The lawyer in this stimulus makes a flawed conditional argument. The argument begins with a rule providing that when a person takes something they have good reason to think it belongs to someone else, then that is stealing, which the lawyer tells us is wrong to do. We can diagram this rule as:


TOPP = take something you have good reason to think is someone else’s property
S = stealing

..... ..... ..... ..... Sufficient ..... ..... Necessary

..... ..... ..... ..... TOPP ..... :arrow: ..... S


Next, the lawyer applies this rule to Meyers. Meyers did not have good reason to think the compost in the public garden belonged to anyone else (TOPP). Based on this evidence, the lawyer concludes that Meyers did nothing wrong by taking the compost. In other words, we can infer Meyers did not steal (S), because stealing is wrong and the lawyer concludes Meyers did nothing wrong.

We can diagram this application of the rule to Meyers, using the subscript M to represent Meyers:


..... ..... ..... ..... TOPPM ..... :arrow: ..... SM


Sadly for the profession, the lawyer has committed a Mistaken Negation. The question stem tells us that this is a Flaw in the Reasoning question. Our prephrase is that the correct answer choice will describe the lawyer’s flawed use of conditional reasoning.

Answer choice (A): The lawyer’s argument involved the application of a rule to Meyer’s act, and did not confuse a factual claim with a moral claim.

Answer choice (B): The argument was limited to the issue of whether what Meyers actually did was wrong. It does not assume what Meyers would not have done.

Answer choice (C): This is the correct answer choice, even though it describes a Mistaken Reversal. Recall that the Mistaken Reversal and Mistaken Negation are contrapositives of each other, and therefore are logically identical to each other. So, in describing a Mistaken Reversal, the answer choice simultaneously describes the Mistaken Negation.

Answer choice (D): Although the stimulus does not expressly consider the possibility that the compost belonged to Meyers, that lack of discussion is not a logical flaw. If the compost was Meyers’, then it would change nothing, because Meyers still would have no good reason to think the compost was anyone else’s property.

Answer choice (E): This describes an error in the use of evidence, in which evidence supporting a position is treated as if it proved the position is correct. The lawyer did not conclude that the compost was someone else’s property.
 MikeRov25
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#30883
How is C correct? I choose B because the lawyer is taking for granted that if Meyers had known that the compost legally belonged to someone else, he wouldn't have taken it. We don't know this to be fact, hence why I said B.

Edit: Oh and C is confusing as heck.
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 Jonathan Evans
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#30905
MikeRov,

You need to review both conditionals and common flaws! This is a pretty classic sufficient/necessary muck-up. The author states as a premise the principle that if you suspect something belongs to someone else and take it, then that's stealing, and that's wrong.
  • Premise: Take something & You suspect it belongs to someone else :arrow: stealing :arrow: wrong
The author then concludes that because Meyers had no reason to believe the compost belonged to anyone in particular, taking it was not wrong. It would look something like this:
  • Conclusion: You don't suspect it belongs to someone else :arrow: not stealing :arrow: not wrong
This is a Mistaken Negation ("Inverse Error," "Denying the Antecedent").

Review and practice conditionals, then work on your prephrasing on Flaw questions. You have to get both the concepts down and then implement them in your execution to come up with strong, accurate predictions for problems such as these.
 spowell4
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#35721
I got this question right, but mainly because none of the other answer choices had conditional reasoning in them. Is this an okay strategy to use? Also it was noted that mistaken reversal is the contrapositive of mistaken negation, but can we only use that as an acceptable answer choice because there isn't a choice with mistaken negation?
 Francis O'Rourke
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#35803
Hi Spowell,

This is a good strategy to use at first. If you see that the speaker made an error in conditional reasoning, then you need to select an answer choice that describes an error in conditional reasoning. Of course, some sets of answer choices might describe two different errors in conditional reasoning. In that case, your strategy would work to narrow down the answer choices so that you can spend a short amount of time reasoning out which answer choice accurately describes the specific conditional error.

In the case that one answer choice describes the Mistaken Reversal, and another describes the Mistaken Negation, you would want to choose the appropriate one. For this stimulus, the Mistaken Negation would be a more appropriate description of the error, even though the two are logically equivalent.
 JulesC
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#71154
Hello,

When originally doing this question the conditional flaw blew over my head, but I noticed a flaw in the logic of the premise "If you take something that you have good reason to think is someone else's property, that is stealing". Logically, this doesn't make sense because "good reason to think" that something is someone else's property is not enough to make it someone else's property, it either is or it isn't. So while doing this question I wasn't sure which flaw to address. The conditional one, or the more straightforward one with the reasoning used.

I feel like this happens quite frequently in the LSAT where there is a flaw in the stimulus but the question is not necessarily asking you to address it. In this case I immediately thought of the first flaw that came into my mind, the one about the definition of stealing, and chose E because I thought it summarized that quite well. How should I know when I'm supposed to address a flaw and when I'm not supposed to?
'
Thanks,

Jules
 James Finch
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#71307
Hi Jules,

Actually, the "flaw" you described isn't actually a flaw at all, and in fact is something that you'll learn about in criminal law class in law school: laws can include an intent requirement/element, and almost all criminal laws do. So even if you happen to be in fact mistaken, you could still be guilty of a crime: if you take something that you reasonably believe to belong to another person without permission, but it actually belongs to you, you could technically be guilty of theft, even if there wouldn't be any actual victim. A more realistic example would be an undercover police officer selling a bag of sugar to someone who is intending to purchase cocaine; the mistake of fact doesn't negate the criminal intent.

For the purposes of the LSAT, we have to take everything given in a stimulus as true, as far as it goes, including any conditional statements. Always be very careful about the precise language being used, as it's easy to assume that one thing is being talked about when it's actually a slightly different but distinct other thing. Try and focus on looking for the flaws that PowerScore lays out, and if you see conditional logic in a Flaw question stimulus, take a second look to test whether it is actually valid or not, as it's likely the source of the flaw that you'll need to identify.

Hope this helps!

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