With regard to this question: LSAT #53, Section #1, Question #20, how is answer choice 'C' an assumption that allows the conclusion to be properly drawn?
To me, answer choice 'C' is somewhat of a recast of the conclusion in the stimulus...and does not really add anything to the premises in the stimulus that would further support the conclusion.
#20 - Biologist: Lions and tigers are so similar to each
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The stim says skeletons can't predict the hunting behavior of lions vis-a-vis tigers. It concludes that skeletons can't let us predict hunting behavior of dead animals.
Answer choice C fits that, though it's more of a general justifying principle, instead of a mere recap. C says that if you failed once to predict hunting behavior from skeletons, then you can't ever predict it from skeletons alone.
I was wondering if you could help explain how to approach this question and why (A) is wrong? After I read the stimulus, the prephrase that came to my mind was "the extinct predatory animals should have similar skeletal structures with lions and tiger"s in order to make the comparison work. I immediately saw choice (A) and negated it into "The skeletons of lions and tigers are not somewhat similar in structure in certain key respects to the skeletons of at least some extinct predatory animals". I thought that weakened the conclusion and moved on. Reviewing the question, I went through all the answer choices and (C) seemed much stronger. What was wrong with (A) though? Thanks!
Let's remember (1) that this a Justify the Conclusion question and (2) what a Justify the Conclusion question does. It requires us to select an answer choice that logically proves the conclusion of the argument.
An easier way to think of it as the easy math-like equation we call the Justify Formula:
Premises + Correct Answer Choice = Conclusion.
If we take the premises of the stimulus and then add answer choice (C) "If skeletal anatomy alone is ever . . . " then the conclusion (Thus, paleontologists . . .) makes perfect sense. Meaning, the reasoning is structurally valid.
Let's see what happens with incorrect answer choice (A). We take the premises from the stimulus and then add answer choice (A) "The skeletons of lions and tigers . . ." then we can't say for sure the conclusion (Thus, paleontologists . . . .)
From your description, you might just have confused this justify the conclusion question for an assumption question and tried to apply the Assumption Negation Technique. Hopefully, now that you see it as a Justify the Conclusion Question and understand the Justify Formula, the answers make a lot more sense.
Hope this helps,
Wouldn't answers (A) and (B) be considered strengthen/assumption answers since they show how extinct predatory animals relate to the lions and tigers? How do they compare to answer (C)?
Answers A and B are definitely not assumptions, LSAT2018. Try the Negation Technique on them and you'll see that they have no impact on the conclusion. I also don't see either one of them as strengthening the conclusion. Lions and tigers are mentioned as evidence that the skeleton alone cannot tell you about the hunting behavior of an animal. They are an example that supports a more general claim. It wouldn't matter if lions and tigers were similar to dinosaurs, or if dinosaurs were similar to each other, or if they were all completely different, as the point was only that the skeleton does not provide sufficient evidence to draw conclusions about that behavior.
Adam M. Tyson
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