LSAT Explanation PT 40, S3, Q5: Sickles found at one archaeological site

LSAT Question Stem

Which one of the following, if shown to be a realistic possibility, would undermine the argument? 

Logical Reasoning Question Type

This is a Weaken question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

This Weaken question presents an argument about the relationship between scratches on sickle blades and their use in harvesting grain. The argument's structure can be summarized as follows:

Premise: Sickle blades always become scratched when used to harvest grain.

Premise: Sickles at the first site had scratched blades, while sickles at the second site did not.

Conclusion: Sickles at the first site were used to harvest grain, while sickles at the second site were not.

An "Evaluate" question for this argument could be: "Is there any other possible cause for the scratches on the sickles found at the first site?"

Now, let's analyze each answer choice:

a) Some sickles that have not yet been found at the first site do not have scratched blades.

- This answer choice does not address the argument about the sickles with the scratched blades that were actually found, so it doesn't weaken the conclusion.

b) The scratches on the blades of the sickles found at the first site resulted from something other than harvesting grain.

- This is the correct answer choice. It introduces an alternative cause for the scratches, thus undermining the conclusion that the scratches must have resulted from using the sickles to harvest grain.

c) Sickles at both sites had ritual uses whether or not those sickles were used to harvest grain.

- The ritual uses of the sickles are irrelevant to the argument, which is focused on whether the sickles at the first site were scratched from harvesting grain.

d) At the second site, tools other than sickles were used to harvest grain.

- This answer choice actually strengthens the idea that sickles at the second site were not used for harvesting grain, so it doesn't weaken the argument.

e) The sickles found at the first site were made by the same people who made the sickles found at the second site.

- The identity of the sickle-makers is irrelevant to the argument, which is focused on how the sickles were used, not who made them.