Drama critic: There were many interesting plays written last year. Surely some will gain widespread popularity for at...

Kim on August 18, 2014

Please Explain

Please explain correct answer

1 Reply

Melody on August 26, 2014

Here we have a Strengthen with Necessary Premise question. Remember that a premise is necessary for a conclusion if the falsity of the premise guarantees or brings about the falsity of the conclusion. First, we check to see if the answer choice strengthens the passage, and then, if it does strengthen, we negate the answer choice to see if its negation makes the argument fall apart. If the answer choice does both those things, then it is our correct answer.

The conclusion of the argument is: none of the plays written last year will be popular several centuries from now.

Why? "The only plays that continue to be performed regularly over many decades and centuries are those that skillfully explore human nature, and none of the plays written last year examine human nature in a particularly skillful way."

Let's diagram:

"The only plays that continue to be performed regularly over many decades and centuries are those that skillfully explore human nature,"

PR: CMPD ==> SEHN
not SEHN ==> not CMPD

(Remember that "the only" introduces a sufficient condition, while "only" introduces a necessary condition.)

"none of the plays written last year examine human nature in a particularly skillful way."

P1: not SEHN

"none will be popular several centuries from now."

C: not PSYN

Answer choice (A) states: "No play will be popular several centuries from now unless it continues to be performed."

(A) PSYN ==> CMPD
not CMPD ==> not PSYN

Answer choice (A) strengthens the argument because we can use the transitive property to connect the contrapositive of the PR to the contrapositive of (A) to get: not SEHN ==> not CMPD ==> not PSYN and conclude: not SEHN ==> not PSYN, i.e. our conclusion. Thus, answer choice (A) supports the argument.

Now, let's negate. Answer choice (A) is a Sufficient & Necessary statement. So we must show the sufficient condition being present without the necessary condition in order to negate it.

Negation: If a play will be popular several centuries from now, then it does not necessarily continue to be performed.

N: PSYN ==> not CMPD
CMPD ==> not PSYN

If we take the negation of answer choice (A) to be true, then that means that continuing to be performed is not a requirement for the play to be popular several centuries from now. Therefore, the fact that none of the plays written last year will continue to be performed regularly over many decades and centuries to come no longer necessarily means we can conclude that none of them will be popular several centuries from now. So, the negation of answer choice (A) makes the conclusion of the argument fall apart.

Thus, answer choice (A) is our correct answer.

Hope that was helpful! Please let us know if you have any other questions.