LR Question 17 Explanation
QUESTION TEXT: Science teacher: In any nation, a flourishing national…
QUESTION TYPE: Most Strongly Supported
FACTS: Successful Economy ➞ Flourishing Science ➞ young people excited about science ➞ good communication
Contrapositive:
Good Communication ➞ Young people excited about science ➞ flourishing science ➞ successful economy
ANALYSIS: I normally don’t draw “most strongly supported” questions, but this one is conditional. All the statements in the stimulus can be connected.
It’s important to remember what your diagram means. There is a time element to these statements. A successful economy requires an active flourishing community. An active flourishing community requires that past young people were once excited. A community might continue to flourish for a while even if current youth are bored with science.
___________
- This is a mistaken reversal of the final sentence.
- “Depends principally”? We know excited young people are a necessary condition, but they may not be the main one.
Something can be a necessary condition without being the principal necessary condition. - CORRECT. This follows from the logical chain I drew in the “Facts” section. A successful economy leads to good communication. That means there was good communication at some point in the past, since that led to past young people getting interested in science and forming the current scientific community.
- The stimulus only says that “many” youth must resolve to become scientists. This answer says “most” youth must actually become scientists. That’s far stronger. Resolving to do something doesn’t mean you’ll do it, and many is not most.
- Nonsense. Good communication was only mentioned as a factor necessary for encouraging youth to want to become scientists. It’s possible that an individual scientific project can succeed without good communication.
Recap: The question begins with “Science teacher: In any nation, a flourishing”. It is a Most Strongly Supported question. To practice more Most Strongly Supported questions, have a look at the LSAT Questions by Type page.
More Resources for Most Strongly Supported Questions
- Intro Course lesson: This intro course lesson covers Most Strongly Supported questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers most strongly supported questions.
I don’t understand how A is a reversal of the final sentence. Aren’t both sentences stating that good communication will lead to excitement about science?
So reversal doesn’t actually mean that they’re stating opposite things (you’re right that both statements involve a link between good communication and excitement about science), but rather that A is reversing the logical structure of the final sentence.
The final sentence says that good communication is necessary to spark excitement. This establishes a necessary condition, i.e. you MUST have good communication for excitement. In other words “If excitement -> good communication”. It does NOT claim that good communication will always result in that excitement; just that without it, the excitement cannot happen.
Answer A, however, reverses this logic into a sufficient condition, stating If good communication -> excitement. This means that A is saying that if scientists communicate well with the public, excitement will necessary occur. This is not supported by the stimulus because the final sentence doesn’t guarantee that good communication is enough on its own to create excitement; it only states that good communication is required for excitement to happen.
So it reverses the conditional logic and therefore goes against the stimulus. Hopefully that clarifies things!
When I did my diagram, I was able to diagram just as you did in your prep work. However, I skipped over C as the correct answer as when I drew out the answer, it appears as a mistaken reversal to me. I am getting very confused with how “unless” works within a conditional framework.
Taking C and diagramming it, I learned that what the “unless” is modifying will be the necessary condition
i,e:
–> Good Communication
Then take what is leftover and that will be negated and become the sufficient condition:
~Successful Economy –> Good Communication
And then finally the “No” in the answer would negate the necessary condition (as in no X is Y is diagrammed as X –> ~Y):
~Successful Economy –> ~Good Communication
This would be a mistaken reversal. I am sure I misunderstood something about how to use “unless” but I cannot for the life of me find a good source to teach me how to diagram it properly including all of my teaching aides.
You can’t succeed on the LSAT unless you learn conditional logic
Succeed –> conditional
You will succeed in law unless you get disbarred
Not succeed –> disbarred
Just look at these a while until it clicks. Write them out with other words. Basically you just negate the thing before unless and leave the thing after unless as the necessary.
In C, the sufficient condition says “no nation can have a successful economy”. So you negate that to: successful economy –> good communication
You’re applying the wrong rule, which is the basis of your troubles. Mind you, the rules are just a shortcut. Using a simple sentence you can understand intuitively is also helpful. Then you get the rule *from* this sentence you already know. e.g.
If cat, then tail
Not a cat unless you have a tail
Both are: Cat –> Tail
Why would it be incorrect to diagram the stimulus as :
Successful Economy –> Flourishing Science young people excited about science –> good communication?
The stim mentions that “many young people” not all young people?
Thanks!
I’m not sure I understand your question (I think you left out an arrow and may have meant to say “why *wouldn’t* it be incorrect). Did you mean to say you think my diagram is incorrect?
I took a small liberty by omitting the word “many”. But it doesn’t make a difference. The left to right flow of the diagram is the same. And in the back of my mind, I knew the question didn’t require that every single young person likes science.
Diagrams are just a tool. When I drew this on page, it was:
E –> F –> S –> C
They’re just representations of the larger idea. When I wrote the explanation, I fleshed them out so they’d be clearer to other people. But the specific words don’t matter. The main idea is: did the diagram correctly capture the left to right flow of the conditionals?
“Many” *can* be a significant word, but in this question is doesn’t matter, because it’s just a link in a conditional chain. Suppose I said “If we give out free money, many people will be happy. And if many people are happy, the nation will be at peace”. This diagram is fine:
Money –> Happy –> Peace
It’s not a full representation of the full conditional statements, nor is it intended to be. It’s just a notation system to condense the English language into logic.