LSAT Explanation PT 41, S3, Q12: Yang: Yeast has long been known

LSAT Question Stem

Campisi counters Yang's argument by 

Logical Reasoning Question Type

This is a Method of Reasoning question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

Let's first analyze the passage and understand the structure of the argument. Yang presents an argument with the conclusion that yeast was known to be a leaven in 1200 B.C. The premise supporting this conclusion is that biblical evidence ties the use of leavens to events dating back to 1200 B.C. Campisi counters Yang's argument by questioning the assumption that if leavens were used in 1200 B.C., it must have been yeast.

The question type for this problem is Method of Reasoning (MOR), which asks us to identify the way Campisi counters Yang's argument.

Now let's discuss each answer choice:

a) This answer choice is incorrect because Campisi does not suggest an alternative set of evidence. Campisi questions the assumption underlying Yang's argument, not the evidence itself.

b) This answer choice is correct. Campisi questions the truth of a presumption underlying Yang's argument, which is the assumption that if leavens were used in 1200 B.C., it must have been yeast.

c) This answer choice is incorrect because Campisi does consider Yang's reason for the conclusion before questioning it. Campisi specifically addresses the assumption that Yang makes in the argument.

d) This answer choice is incorrect because Campisi does not point out that Yang's premises more strongly support a contrary conclusion. Instead, Campisi highlights the possibility of other leavens being used in 1200 B.C., which questions the validity of Yang's conclusion.

e) This answer choice is incorrect because Campisi does not call into question the truth of the evidence presented by Yang. Instead, Campisi questions the assumption Yang makes based on that evidence.

In summary, the correct answer choice is (b) because Campisi counters Yang's argument by questioning the truth of a presumption underlying Yang's argument.