http://classic.7sage.com/lsat_explanations/lsat-66-section-2-question-20/
Not having problem with solving this question but having problem with how to diagram a specific sentence.
Carrie: "the only thing that can be required for an action to be morally good is that it fulfill a moral obligation."
J.Y diagrammed this as bi-conditional. I am having a hard time to see it. Although it does have both sufficient and necessary indicators ("the only" and "required"), I just don't see how Fulfill Moral Obligation(FMO) can be sufficient for Morally Good. Intuitively, saying FMO is the only requirement does not seem to indicate that it is sufficient. Technically, I couldn't break this sentence into two sentence (one using the sufficient indicator and another using the necessary indicator) like J.Y has done for the other bi-conditionals.
Any thoughts?
I think your confusion with this question stems from misinterpreting the first three sentences. First sentence presents a problem. Second sentence tries to explain the reason for problem, but note it is an ascription- "it has been said..." (a.k.a. hinting the author does not agree with this explanation. In the third sentence, the author's rejection to the explanation is clearly said. If "those with great vocal are most likely to ruin voices" then lack of vocal power (maturity) cannot be the explanation. Then, the last two sentences presents author's view of what the problem is.
The correct answer combines first and last sentences in the form of problem/explanation. I don't think there is formal logic involved. The first most statement in your diagram cannot be drawn because it is not the author's opinion.
@7sagestudentservices , hope this helps!