PrepTest 111
[lcid:3540] Prep Test 111 LSAT — Logical Reasoning — S1
Logical reasoning
Question prompt
Novelists cannot become great
Remaining source text redacted.
Why the credited answer is right
Credited answer: D
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Strengthen with Necessary Premise Questions
Answer choices
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ANovelists require some impartiality Remaining source text redacted.
Why choice A is not credited
Incorrect. Impartiality isn't mentioned in the stimulus, nor is it inherently related to any concepts raised there, so this answer is out of scope. -
BNo great novelist lacks Remaining source text redacted.
Why choice B is not credited
Incorrect. Powers of observation and analysis were tangential to this argument since those skills didn't link directly to the conditional chain that was set up to support the conclusion. Since the argument doesn't link those skills to being a great novelist (or even a novelist, since they're just helpful and not necessary), an answer saying they're necessary is incorrect. -
CParticipation in life, interspersed Remaining source text redacted.
Why choice C is not credited
Incorrect. First, this answer is causal ("make") whereas the argument is conditional so causality doesn't need to be assumed. Second this answer brings up impartiality which is out of scope as it was in (A). Third the argument concludes that something is sufficient to ensure a novelist won't be great so an answer establishing a sufficient condition for being a great novelist is a reversal of the logic needed. -
DNovelists cannot be great Remaining source text redacted.
Why choice D matches the stem
Correct. Argument or Facts:
Argument
Valid or Flawed:
Flawed
Question Type:
Strengthen with Necessary Premise
Stimulus Summary:
Intuitive grasp of everyday emotions → Immersion in everyday life
Academic → not Immersion in everyday life
Therefore — Academic → not Great novelist
Answer Anticipation:
This Strengthen with Necessary Premise question has uncommon conditional keywords, but they are present and so we should use formal logic to understand the argument. Those keywords? "Cannot" "as long as" "only" and "precluded."
Before we walk through the diagrams we want to make a note—the second sentence before the "but" isn't conditional—being useful isn't the same as being necessary or sufficient to be a novelist—so we should put that aside as it's unlikely to factor into the argument or answer.
Now back to the conditionals. "As long as" is equivalent to "if" and "cannot" is a necessary indicator which is how we ended up with the diagram of the conclusion (since the first statement is what the rest of the argument supports it's the conclusion). "Only" introduces a necessary condition explaining the first conditional premise in our summary.
"Precluded" is an interesting one—the word means "this thing prevents this other thing." In other words the thing that is doing the precluding is the sufficient condition for the negation of the thing being precluded. Failing to study precluding a good LSAT score translates to "If you fail to study then you won't get a good LSAT score." That's the second conditional premise.
With that all noted it's time to find the gap in the argument. Let's build a chain using the premises and the conclusion. The premises discuss being an academic—the second guarantees that an academic isn't immersed in everyday life. The first premise when the contrapositive is taken builds off of that to say that being an academic means you don't have an intuitive grasp of everyday emotions. However at that point we run out of premises so we have:
Academic → not Immersion → not Intuitive grasp of emotions . . . → not Great novelist
As such we're missing that last step: not Intuitive grasp of emotions → not Great novelist
Let's find an answer stating that.
Answer Explanation:
not Intuitive grasp of emotions → not Great novelist ("without" being treated here as "if not"). This matches our anticipation filling in the gap in the conditional logic. If this link doesn't exist then the conditional chain doesn't build to the conclusion and the whole argument falls apart. This answer is therefore necessary for the argument to work.
Key Takeaway:
When a Strengthen with Necessary Premise question features multiple conditional premises chain them together and find the missing link between the chain and the conclusion! -
EKnowledge of the emotions Remaining source text redacted.
Why choice E is not credited
Incorrect. This answer more or less restates the first conditional premise with "intuitive grasp" changed to "knowledge" and "immersion in life" replaced with "merely observing and analyzing" life so it isn't a necessary assumption.
What this tests
Discussion
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S&N Diagramming 1 reply
Started by Anna20
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Why not A 2 replies
Started by JayDee8732