LR Question 21 Explanation
QUESTION TEXT: No occupation should be subject to a licensing…
QUESTION TYPE: Principle – Justify
PRINCIPLE: Licensing requirement ➞ incompetence endangers human health or safety
contrapositive: no threat to health or safety ➞ no licensing requirement
ANALYSIS: Note that the principle gives a necessary condition for licensing. It doesn’t tell us when we should license. So any answer that says “and therefore we should license” is wrong.
That’s C, D and E. I try to avoid saying “same as C” for an explanation, but C, D and E are literally the same answer. They all mix up necessary and sufficient. If you try to analyze them on any other level, you’re missing the issue. It’s a trap to try to analyze content on these structural questions.
We can only conclude when something shouldn’t be licensed. (When there is no threat).
___________
- “Some of the duties” isn’t all of the duties. It’s possible (damned near certain, actually) that some other duties of police offers can endanger human safety if done incompetently.
- CORRECT. This matches the contrapositive: if poor work poses no plausible threat, then no license is needed. “Because” just links the premise to the conclusion.
- See the analysis above. This gets the logic backwards. It says there is a threat, so there should be a l license. But the principle only gives a necessary condition, not a sufficient one. It can’t justify licensing, only not licensing.
- Same as C.
- Same as C and D.
Recap: The question begins with “No occupation should be subject to a”. It is a Principle – Justify question. To practice more Principle – Justify questions, have a look at the LSAT Questions by Type page.
More Resources for Principle Questions
- Intro Course lesson: This intro course lesson covers Principle questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers principle questions.
All of the AC use “because”, so I think it is causal relationship which mean double arrows like “”. How can fix “because part” as sufficient and “the remaining parts” as necessary?
I have trouble to figure out B and C… Any help?
Because introduces the reasoning. So, for example:
Dogs are the best:
A. Because only dogs can fetch a newspaper
B. Because all dogs are friendly
You can see because has no impact on what is necessary and sufficient in each statement. The first is FN –> D and the second is D –> F. Because just links the reasoning with the conclusion.
Note: This is an old comment but I wanted to clarify the point.
I’m slightly confused. I understand how the statements are selected, but I thought the presence of unless causes us to use the “unless equation” ( the term modified by unless becomes the necessary condition and the rest is negated and becomes the sufficient condition.) If this is true, shouldn’t the diagramming be “no threat to health or safety –> no licensing requirement” and the contrapositive “subject to licensing requirement –> threat to health or safety?”
Good question. So, on any statement, both the statement and the contrapositive are equivalent statements. With something like “Cats are cute” it makes sense to draw this as “Cat –> Cute” and have not cute –> not cat be the contrapositive.
But with unless the phrase is twisted enough there are a few different ways of sorting it out. The way I think about them is:
Negate the thing before unless nad make it sufficient
The thing after unless is necessary
Which is how I drew it. You’ve got a different translation rule which gets you the same answer, except you draw the contrapositive form from it.
But they’re the same thing logically. If you swap your statement and your contrapositive, you’ll see you have the same statements as I do. Meaning, we both have interpreted the statement correctly. It doesn’t really matter which one you label “contrapositive”. Contrapositive is just in reference to an original statement, it’s a tool for getting the alternate form of the statement which is also true. But it’s not a thing which exists independently of a statement.
So if you have figured out the two true things about any conditional statement then you have figured out what you need to. I wouldn’t translate unless as you have but that doesn’t make me right and you wrong: we both have the same two true statements.
Note: This is an old comment but I wanted to address the point.