#18 - Police captain: The chief of police has indicated that

[Administrator]

Question #18: Flaw—SN. The correct answer choice is (B).

This is a challenging question for one reason only: it requires close reading and very close attention to detail. The police captain’s argument is structured as follows:

Premise—Gifts of cash or objects valued at more than $100 count as graft.

Premise—No officer in my precinct has ever taken such gifts.

Conclusion—The accusations of graft in my precinct are unfounded (i.e. no one is guilty of graft).

At first glance, this looks like a valid argument, as long as we assume that the police captain’s certainty is not misplaced. This being the LSAT, certain knowledge should be taken at face value—let’s assume that the captain’s premise is correct, and that no one in his precinct has ever taken such gifts. Does that establish that no one can be accused of graft? Not necessarily! Gifts of cash or objects valued at more than $100 simply count as graft: they are a type—an example—of graft. For all we know, graft is a much broader term that captures all sorts of political embezzlement, influence peddling, or other forms of political corruption.

Consider an analogous argument: Jane has never stolen a Corvette. Therefore, Jane is not a car thief. The police captain is guilty of the same logical fallacy, albeit one that is more difficult to catch.

Answer choice (A): This answer choice is attractive, but incorrect. The police captain does not rely on a limited sample of officers (for instance, he never said, “no officer I know of has ever taken such gifts”). His evidence is quite definitive: no officer in my (entire) precinct has ever done this. Not one. This is not a small sample.

Answer choice (B): This is the correct answer choice. If there are other instances of graft besides those indicated by the chief of police, it is entirely possible that some of the officers in the captain’s precinct have been rightfully accused of graft.

Answer choice (C): In defending his officers, the captain’s makes no mention of their character or motivations. This answer choice describes an entirely different fallacy.

Answer choice (D): The captain’s argument does not extend to a rebuttal of any accusation of corruption.

Answer choice (E): This answer choice describes an internal contradiction, for which there is no evidence in this argument. This would be like saying, “I know one of my officers took a bribe, but he had no other choice—his house was being foreclosed, and he would have been homeless. Therefore, the recent accusations of graft are unfounded.”

[mokkyukkyu]

At first I thought this is part-whole question too...so ppl cannot tell what's the whole is by knowing just each part of the whole.
Is this a part-whole question?

[Adam Tyson]

No part-to-whole fallacy here, mokkyukkyu, although the authors certainly want to catch a few people thinking that's so.

Part to whole in this case would probably be something like "no officers in my precinct took the money, so nobody in the police department is guilty of graft". There, the captain would be taking info about a part (his precinct) and applying it to the whole (the department). He didn't do that - he limited his response to his precinct.

The problem here is a mistaken negation: If you take the cash, you are guilty of graft, but nobody took the cash, so no graft. Graft, the Necessary Condition, could be present even if cash gifts over $100, the Sufficient Condition, are absent.

[Ozar114]

I didn’t choose B because I felt like the answers asked t me to bring in information I wasn’t allowed to.

[Adam Tyson]

No new information is required here, Ozar114, just a description of what the argument did wrong. Failing to consider something that should be considered isn't new information - it's pointing out what should have been there all along! Also take note of the "may" in the answer choice. That means the author isn't saying that there ARE other instances of graft (which would be new information), but only that there MAY be (which isn't). Compare this, for example, to a causal argument, where a common flaw is a failure to consider that there may be another cause. It's not new information to suggest that maybe something else caused the effect, because that is always a possibility built in to every causal claim.

One more way to look at this question (and this can be done with any flaw question) is to consider what the author must have assumed in coming to their conclusion. In this case, the author must have assumed that there was no other type of graft besides the one mentioned. But what if that assumption turned out to be false? Pointing out a bad assumption is what flaw answers do, and again, that isn't new information, but just pointing out what was inherent, but unstated, in the argument.

[sonohan]

Thank you for the explanation. What threw me off was the following wording: "besides THOSE indicated by
the chief." This part of the answer choice was confusing because the Chief didn't indicate or mention ANY cases of Fraud. So I didnt chose this this answer since it was referring to somethiong which I felt was out of scope in the original statement. Can the "complete absence of mention" of fraud be considered "mention" of fraud?

thank you and good luck studying to all!

[Jeremy Press]

Hi sonohan,

That reference in answer choice B ("instances of graft beside those indicated by the chief of police") is to the first sentence of the stimulus, which says, "The chief of police has indicated that gifts of cash or objects valued at more than $100 count as graft." So the instances the chief of police has indicated count as graft are gifts of cash/objects valued at more than $100. And answer choice B says the problem is there might be graft outside of just that, i.e. other kinds of graft or gifts that are valued less than $100, which is a problem for the argument because the argument doesn't tell us whether any officers in the precinct have taken those kinds of gifts.