LSAT Explanation PT 29, S1, Q7: In Debbie's magic act, a volunteer

LSAT Question Stem

Which one of the following most accurately describes a flaw in the skeptic's reasoning? 

Logical Reasoning Question Type

This is a Flaw question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage. The argument can be summarized as follows:

Premise 1: In three trials, the skeptic found no evidence of sleight of hand, a trick deck, or a planted volunteer.

Conclusion: Debbie does not use sleight of hand, a trick deck, or a planted volunteer to achieve her effect.

The structure of the argument is that the skeptic tests for three methods (sleight of hand, trick deck, and planted volunteer) and, based on the trials, concludes that Debbie does not use any of these methods. However, the skeptic's reasoning might be flawed because there could be other possibilities that have not been considered.

An "Evaluate" question for this argument could be: "Did Debbie use the same method in all three trials?"

Now, let's discuss the answer choices:

a) The skeptic failed to consider the possibility that Debbie did not always use the same method to achieve her effect.

This is the correct answer. The skeptic's reasoning is flawed because they did not consider the possibility that Debbie might have switched her methods during the trials. For example, she could have used sleight of hand in one trial and a trick deck in another.

b) The skeptic failed to consider the possibility that sleight of hand could also be detected by some means other than videotaping.

This answer choice is incorrect because it does not address the actual flaw in the skeptic's reasoning. The issue is not whether there are other ways to detect sleight of hand, but rather whether Debbie might have switched her methods during the trials.

c) The skeptic failed to consider the possibility that Debbie requires both sleight of hand and a trick deck to achieve her effect.

This answer choice is incorrect because it does not address the actual flaw in the skeptic's reasoning. The issue is not whether Debbie needs multiple methods simultaneously, but rather whether she might have switched her methods during the trials.

d) The skeptic failed to consider the possibility that Debbie used something other than sleight of hand, a trick deck, or a planted "volunteer" to achieve her effect.

This answer choice is incorrect because it does not address the actual flaw in the skeptic's reasoning. While it's true that Debbie might have used a different method, the conclusion of the argument is that she does not use any of the three mentioned methods. The skeptic's reasoning is flawed because they did not consider that Debbie might have switched her methods during the trials.

e) The skeptic failed to consider the possibility that Debbie's success in the three trials was something other than a coincidence.

This answer choice is incorrect because it does not address the actual flaw in the skeptic's reasoning. The issue is not whether Debbie's success was a coincidence, but rather whether she might have switched her methods during the trials.

In conclusion, the correct answer is (A) because the skeptic's reasoning is flawed due to not considering the possibility that Debbie might have switched her methods during the trials.