LSAT Question Explanation
PT 101, Section 3, Question 10
Sufficient AssumptionArgument structure
The spirit is not a material body.
All material bodies are divisible into parts, and all material bodies are imperfect.
Explanation
There's a clear flaw in this argument because based on the evidence we don't know anything about the spirit. The spirit is a new concept introduced in the conclusion.
We do know about material bodies, however. The evidence tells us that all material bodies are divisible into parts, and all material bodies are imperfect.
Ok, so we could prove the spirit is not a material body with a sufficient assumption that shows the spirit doesn't have at least one of those qualities.
My prediction is that the answer choice will tell us either that the spirit is indivisible or that the spirit is perfect.
Answer choices
This doesn't tell us about the relationship between the spirit and material bodies, so it definitely doesn't prove the conclusion.
Similarly to (A), this doesn't tell us anything about whether the spirit is a material body.
This answer (finally) talks about the spirit, but it doesn't prove that the spirit is not a material body. We know from the evidence that material bodies are divisible, so if the spirit is also divisible, then the spirit could be a material body.
There we go! This matches my prediction. If the spirit has a quality that no material bodies have, then that proves that the spirit is not a material body.
So the first part of this seems tempting because it matches my prediction - if the spirit is indivisible, that would prove it's not a material body. But (E) says either indivisible or imperfect, and if the spirit is imperfect that doesn't prove anything. If the spirit is imperfect than it could be a material body - so saying either of these characteristics would prove that the spirit is not a material body is false.