#21 - No occupation should be subject to a licensing

[Administrator]

Complete Question Explanation

Must Be True-PR, SN. The correct answer choice is (B)

As a reminder, "Principle" questions are best understood first according to the task that they are asking you to accomplish. Every "Principle" question is a variant of another question task with which you are likely familiar from your LSAT preparation. The principle itself is a rule that you use to accomplish this task (and is often conditional). In this case, we are asked to find information in the stimulus to support information in an answer choice, so we have a Must-Be-True scenario. Follow the process for Must-Be-True. First, establish the parameters of the principle. Here we encounter necessary and sufficient conditions as indicated by the presence of "unless," and so our first order of business will be to identify these components of this relationship.

In this case "unless" modifies "incompetence leading to public safety threat," and thus "incompetence leading to public safety threat" is the necessary condition. the remainder is negated and becomes the sufficient condition, and so "Licensing requirement" is the sufficient condition. This conditional is symbolized as follows:

• Licensing Requirement incompetence poses threat to public safety
  
  LR ITPS

Now in the answer choices you must find a scenario that follows this rule, or follows the contrapositive of this rule (since the two are identical in meaning). In doing so, note that only two possible conclusions will be viable in an answer choice here:

• 1. ITPS. Given the conditional statement above, we could add another premise establishes LR, which would create the Repeat Form of the argument.
  
  2. LR. If we added ITPS as a new premise, that would enact a contrapositive and force the conclusion that LR.

Knowing the above, you can seek answers with those conclusions, and avoid answers that attempt to conclude LR (which would likely be the result of a Mistaken Reversal) or ITPS (which would likely be the result of a Mistaken Negation). If this point does not make sense here, stop and work out why only two conclusions are possible, and that the other two conclusions are incorrect. further information can be found in the Principle section in your OSC or in the LR Bible.


Answer choice (A): Check the information here: Some duties pose no threat to safety. That doesn't tell us enough to know about all the tasks carried out by police officers, and common sense would suggest that police would have some duties that relate to human health and safety.

Answer choice (B): This is the correct answer choice. There is no conceivable threat to public safety from interior designers, and thus no threat to safety, which is the same as ITPS. This enacts a contrapositive, which results in the conclusion that LR. This matches the conclusion in answer choice (B), and thus this answer is correct.

Answer choice (C): This is a Mistaken Reversal, and can be diagrammed as ITPS LR. Since it's the other way around, this answer is incorrect. note how this answer attempts to conclude LR, which cannot be validly done given the conditional relationship in the stimulus.

Answer choice (D): This is the same idea as answer choice (C), another Mistaken Reversal. It tries to differentiate itself from (C) by perhaps lessening the degree of harm that hair stylists could cause at any one time (making students like this less than (C)) or by making it seem as though hair stylists would be more proximate to any harm they do cause (making students like this more than (C)). But regardless, the relationship here is the same as ITPS LR.

Answer choice (E): A third Mistaken Reversal in a row. The answer begins by describing a scenario that conforms to ITPS, and then attempts to conclude LR, which is the same as ITPS LR.

[alexmcc]

I fell down the MR trap on this one after not slowing down to pick apart the dense wording. I crossed out B because I thought . I noticed C didn't have anything about "incompetence", so I thought I was on track and looked at D and E. I noticed they were the same. I went with E because it sounded more plausible. It's good to know I was way off so I know what to fix.

My diagram was:

(Incompetence ---> Threat to Human Health OR Threat to Human Safety) ----> License

After re-diagramming and looking at admin's response, I got

License --> (Incompetence --> Threat to Human Health OR Threat to Human Safety)

I remember looking at some other write-ups about nested conditionals on older questions, and this one looks like a nested conditional.

[Adam Tyson]

You certainly could approach this as a nested conditional, alexmcc, and your second attempt hits the nail on the head. Good work! However, you might also notice that the relationship between incompetence and a threat is a causal relationship, and make that causal claim the necessary condition, thus:

License Incompetence poses a threat

Then, the contrapositive is much easier:

Incompetence poses a threat License

Either way, it looks like you've got it now. Well done!

[goingtosomewhere]

Could someone clarify for me why it is a mistaken reversal? Is it because the word "because" in the answers means it is the sufficient condition in the diagram?

When I was going through, I chose E and diagrammed it like so: Tattoo artists subject to licensing requirement (because) Pose Threat

I'm also curious why in the original post's explanation about why B was correct, a double arrow was used.

Thank you!

[Dave Killoran]

Hi Going,

I've rewritten this explanation, so please check that out! A few additional thoughts for you:

* The double arrow originally in (B) was not being used as a representation of an actual relationship in the answer choice, but as an "equal" sign meaning the two terms under discussion there had the same meaning: no threat to safety TPS. That's inherently confusing, so I removed it.

* As for the Mistaken Reversal, I'm not sure what that is in reference to. Each of (C), (D), and (E) are Reversals. If you need more info, just let me know.

* And with (E), you have it backwards. It's instead along these lines:

• Premise (from stimulus): LR ITPS
  
  Premise (from (E)): ITPS (introduced by "because")
  
  Conclusion (from (E): LR

Thanks!


Thanks!

[TootyFrooty]

I get the conditional reasoning explanation, I had the conditional correct but somehow skipped B idk why. I'm curious to know what gives away cause and effect in this as per Adam's post?

[Adam Tyson]

"Poses" is the key word there, TootyFrooty. If incompetence poses a threat, that's active and causal, not passive and conditional. It's making something dangerous. It's creating a bad situation. These are all causal ideas.

[lsatlies]

Another absolutely terrible question. When someone says "You don't need a license except if X", they are also saying "If X, you need a license" - in their own words, this is the scenario in which a license WOULD be required. Could there be additional conditionals attached to the stated premise of 'if human health/safety is threatened, you need a license'? Sure. But the author doesn't mention any, so they effectively don't exist. This is certainly not a mistaken reversal - the author's own premises clearly justify that for all those answers, you WOULD need a license.

[Robert Carroll]

lsatlies,

Your interpretation of the conditional is incorrect. As our initial post points out, using the Unless Equation, the conditional relationship expressed in the stimulus is as follows:


Licensing Requirement incompetence poses threat to public safety

What you've expressed is the Mistaken Reversal of that relationship, and thus is not stated nor entailed by what the stimulus expresses. The LSAT is very consistent on the point of how to interpret the word "unless". Note that this isn't just a PowerScore or LSAT thing, either - I'm looking at my copy of Deductive Logic by Warren Goldfarb (a Harvard professor of logic), and on page 30 of that book, the word "unless" is discussed. His interpretation is entirely consistent with what we've diagrammed, and what the LSAT always means when it uses "unless".

You might have been thrown off because your paraphrase inserts the word "if" into the stimulus, but none is present.

Robert Carroll