Logical reasoning PrepTest 134 · Section 3 · Question 14

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Amot: Making a change in government would eliminate the worst social ills.

Subscriber: Amot's argument rests on an assumption, so the conclusion is false.

Answer Anticipation:
The Subscriber's argument concludes that an opposing viewpoint's conclusion is "false"—not that it's unsupported, or that Amot fails to establish it, but that it's false. This is a hint towards a common error in reasoning—the absence of evidence flaw. In this flaw, the author uses a shortcoming of the opposing point to determine that their conclusion is false.

While a shortcoming in an argument proves that the conclusion could be false, it doesn't prove that it is false. Here, since the Subscriber uses the "dubious assumption" of the opposing point to discredit its conclusion, she does commit an absence of evidence flaw. Even if that dubious assumption does turn out to be false, there may be a separate argument for the same conclusion that is valid.

Answer Explanation:
This is the general form that an absence of evidence flaw answer takes. Conclusions aren't proven false if one argument for it is shown to be faulty.

Key Takeaway:
Whenever the conclusion of an argument is that an opposing point is wrong/false, check to see if that's based on a positive argument against the conclusion, or a negative argument against the opposing argument. If the conclusion is based on a shortcoming in the opposing point, then there's an absence of evidence flaw.

Note that the conclusion has to be that the opposing point is wrong, not just unproven, for this common error in reasoning to apply.

Incorrect. This answer is describing an illegal reversal, but there are no conditional statements presented in the argument.

Incorrect. This answer is in the ballpark. However, it describes an argument where the falsity of the conclusion is established as a premise, and that's used to discredit the assumptions—not that the presence of an assumption allows the falsity of the conclusion to be concluded. This answer is essentially the opposite of what we're looking for.

Incorrect. Pointing out an assumption of the argument is different from misconstruing it. This straw man answer choice, therefore, is wrong—the Subscriber would have to restate Amot's argument while changing it for it to be correct, and there's no indication that the assumption she points out doesn't reflect Amot's actual beliefs.

Incorrect. Both uses of government refer to the organization that's running a polity, so there's no equivocation.