#17 - Magazine article: Punishment for crimes is justified

[Administrator]

Complete Question Explanation

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

This is an excellent separator question. If you track and identify the proper indicators, this question seems relatively easy. If you fail to note the indicators, this question can seem confusing and difficult.

The key to the problem is recognizing the sufficient condition indicator “if” in the second line. This indicator creates the following conditional relationship in the first sentence:

• S N
  
  Punishment deters Punishment justified

The second sentence states that the data shows that punishment of crimes is not a deterrent, which can be represented as follows:

• Punishment deters

Using these two premises, the magazine article concludes in the last sentence that punishment is not justified:

• Punishment justified

When seen in relation to each other, the pieces of the argument appear as follows:

• Premise 1: Punishment deters Punishment justified
  
  
  Premise 2 + Conclusion: Punishment deters Punishment justified

The article contains a classic Mistaken Reversal in this argument: just because the sufficient condition does not occur does not mean that you can conclude that the necessary condition does not occur. Upon recognizing this flaw, you should quickly accelerate into the questions, seeking an answer choice that addresses the condition nature of the mistake.

Answer choice (A): Students who fail to identify the conditional reasoning error in the argument often select this answer choice. But, the article works hard to show that the data was valid: “a great deal of carefully assembled and analyzed empirical data show clearly” (emphasis added). As there is no reason to suspect that the data may be biased, this answer choice is incorrect.

Answer choice (B): This answer choice describes the uncertain use of a term. However, the article is consistent in its use of the term “punishment.”

Answer choice (C): This is the correct answer choice. This answer describes the conditional error that underlies both Mistaken Negations and Mistaken Reversals, namely that these two errors are based on confusing a sufficient condition and a necessary condition.

Answer choice (D): Punishing the innocent is not a part of the argument, and the article is not obligated to address this issue. Thus, although the article does not address mistakenly punishing the innocent, this is not a flaw, and this answer choice is incorrect.

Answer choice (E): This answer choice describes a flaw that is the opposite of an overgeneralization, namely that instead of generalizing from limited data, the article draws a detailed conclusion from data that is too generalized. However, the conclusion is about punishment and whether it is justified, and the rest of the article is about topics that are not broader than this topic. Thus, the answer is not overly precise in drawing the conclusion.

[kristinaroz93]

So this problem is a sample one on page 7-11 of the powerscore lsat course book; lessons 5-8.
It states this logical relationship:
premise 1: punishment deters-->punishment justified
premise 2: Punishment not deterred
conclusion: Punishment never justified.

The answer as taken from the answer choices is that it mistakes being sufficient to justify punishment for being required to justify it. I know this would be the answer without giving too much thought as it is the only choice in the set that contains the words "sufficient" or "neccessary", and given that this is a conditional reasoning problem, it makes sense that it would be the answer.
The problem, however, is that I feel a bit confused with the wording of the answer choice itself (probably just because it leaves out the term deterred). Is it basically saying that it makes the term "deterred", which is sufficient to justify punishment, as actually being required to justify it.
...or essential this statement: punishment justified-->punishment deterred.

I fear this is a very silly and obvious question, but would still like to know the answer to anyhow.

Thanks in advance!

[Nikki Siclunov]

Hi kristinaroz93,

Your question is neither silly nor obvious, so I'm very glad you asked it Your fundamental approach is absolutely correct: you recognized there is something messed up with the conditional structure of the argument, and zeroed in on the answer choice that contains the requisite key words. This approach won't always work, as there are other ways for them to describe flaws in conditional reasoning, but it surely does work here. The issue you are having concerns the actual wording of the correct answer choice.

Let's take a look at the argument more closely:

Premise: Deter Justified
Conclusion: NOT Deter NOT Justified

The conclusion is clearly a Mistaken Negation of the premise, so why does the correct answer choice sound like a Mistaken Reversal? Notice that the MN and MR are contrapositives of each other! By saying that, "If punishment does not deter crime, it is never justified," the author is essentially saying that "if punishment were justified, it would have to deter crime":

Conclusion: NOT Deter NOT Justified
Contrapositive: Justified Deter

The contrapositive is implicitly assumed by the conclusion, and it is this implicit assumption that the correct answer choice describes: the argument mistakes something sufficient to justify punishment (deterrence is sufficient, according to the premise) for being required to justify it (the conclusion assumes, by the contrapositive, that deterrence is required to justify punishment).

Technically, every MN mistakes a sufficient condition for a necessary condition, because it argues that without the sufficient condition, you can't have the necessary condition:

A B
NOT A NOT B

By contrast, every MR mistakes a necessary condition for a sufficient condition, because it argues that the occurrence of the necessary condition ensures the occurrence of the sufficient:

A B
B A

There are many ways to describe each logical flaw, but as long as you are clear on why these are actual flaws in the reasoning, you shouldn't have too much trouble identifying the correct answer choice.

Hope this helps! Let me know.

Thanks

[kristinaroz93]

Once again thank you so much for all your help, it is greatly appreciated!

[jessicamorehead]

Hello,

For flaw question types involving conditional logic, will there ever be two answer choices, one describing a mistaken negation and the other describing a mistaken reversal? Or is that impossible because they would essentially mean the same thing? I'm getting confused because I originally saw the flaw as a mistaken negation, but answer choice C describes a mistaken reversal (based on the contrapositive).

[Adam Tyson]

I've never seen them do that, Jessica, nor would I ever expect to see that, for exactly the reason you gave - Mistaken Reversals and Mistaken Negations are the contrapositive of each other, and are therefore logically equivalent statements. They are indeed describing the same thing!

Now what I HAVE seen them do is give one answer that describes a conditional error, either negation or reversal, and another answer that describes a contrapositive, which is of course valid. Be careful there! If it's a flaw question, a contrapositive is NOT a flaw! If you simply pick the first answer that you come across that has conditional indicators in it, as some students will do, you could be falling into their trap!

Good question, and good analysis, Jessica!

[jessicamorehead]

Adam,

Thank you for your thorough reply! I have never even thought about there being a valid contrapositive in the answer choices, so that's a good point to add to my notes. Have a lovely day!

Jessica

[cmorris32]

I've never seen them do that, Jessica, nor would I ever expect to see that, for exactly the reason you gave - Mistaken Reversals and Mistaken Negations are the contrapositive of each other, and are therefore logically equivalent statements. They are indeed describing the same thing!

Now what I HAVE seen them do is give one answer that describes a conditional error, either negation or reversal, and another answer that describes a contrapositive, which is of course valid. Be careful there! If it's a flaw question, a contrapositive is NOT a flaw! If you simply pick the first answer that you come across that has conditional indicators in it, as some students will do, you could be falling into their trap!

Good question, and good analysis, Jessica!

Hi Adam!

How would the LSAT describe a contrapositive using the language commonly used on Flaw answer choices? Would it be something along the lines of: "mistakes the absence of a necessary condition to mean the absence of a sufficient condition"?

I just want to make sure I know how it is described so I don't fall into that trap! Thank you in advance!
- Caroline

[Adam Tyson]

That's exactly right, Caroline. Or they might say "the argument presumes that because one condition is sufficient to guarantee the occurrence of a second condition, the failure of the second condition guarantees the failure of the first." Or something like that.