Logical reasoning PrepTest 121 · Section 1 · Question 23

Incorrect. This answer establishes a conditional rule and then validly applies the contrapositive. This answer is parallel to the valid portion of the argument, but it doesn't then take an additional, flawed step as the stimulus does.

Incorrect. We can be pretty certain this answer is wrong when it presents two conditional rules. The stimulus was flawed because it treated the first statement as being stronger than it actually was—it treated it as saying that the physical sciences only uses statistical analysis, which is a conditional relationship. Since the stimulus assumed a non-conditional statement was conditional, it's almost certain that an answer that presents the matching statement as a conditional won't have the same flaw. Here, the argument has a premise that establishes the negation of the necessary condition is true in "some" cases, which isn't parallel to the stimulus.

Incorrect. This answer has a Perception vs. Reality flaw—there's no way to find something out (perception), so that thing can't apply to the reality of the situation. Different flaw, so this answer is incorrect.

Incorrect. This answer has a similar Perception vs. Reality flaw to answer (C). The argument does establish a conditional rule that gives us a necessary condition for determining which explanation for the origin of the universe is correct, and that necessary condition is "impossible" to meet. That allows the conclusion that it's impossible to determine which explanation is correct (perception). However, the conclusion states that none of them are likely to be correct (reality), so this answer is flawed for a different reason.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
Statistical analysis is a common tool in the physical sciences
Use statistical analysis → Events with replicable details
Human mental events: not Events with replicable details
Intermediate conclusion - Human mental events: not Use statistical analysis
Therefore - Human mental events: Can't be explained by physical sciences

Answer Anticipation:
This argument has some complexity to it, as it has an argument leading up to an intermediate conclusion, and then it backs up and uses a premise with that intermediate conclusion to reach a main point. Let's take a look at each "piece" of the argument.

The first statement is about statistical analysis and the physical sciences, but the argument neglects to discuss the physical sciences until it reaches the main point, so let's put this aside for a second.

The argument leading up to the intermediate conclusion establishes a conditional rule, shows that a specific situation doesn't meet the necessary condition of that rule, and concludes that the specific situation also doesn't meet the sufficient condition. That's a valid application of the contrapositive, so this portion of the argument is valid!

Now let's go back and take a look at the initial premise and how it works with the intermediate conclusion to lead to the main point. Since the argument supporting the intermediate conclusion is valid, the argument must be flawed in its jump to the main point.

That argument has two premises—statistical analysis is a common tool of the physical sciences, but it can't be used to explain human mental events. This lets us conclude that a common tool of the physical sciences can't be used to explain human mental events, but there could be other tools of those sciences that could be used to explain these events. Therefore, concluding that the physical sciences can't be used to explain human mental events is flawed.

We only need to match the flawed elements of the stimulus, so we only need an argument that establishes one type of explanation in a certain field can't be used in a specific situation, and concludes that therefore that field can't be used in that situation. If it also has a valid intermediate conclusion, that's just gravy.

Answer Explanation:
"A good way" matches up with "a common tool" from the stimulus—and the fact that there's a parallel element key to the flaw is a good sign for this answer. This answer then goes on to provide a conditional rule and negate the necessary condition of that rule. While that allows for a valid conclusion to be drawn, this argument—like the stimulus—goes past that valid conclusion (here, that a coherent narrative can't be constructed) to say that the field that uses that tool can't be applied. This answer is flawed in the same way as the stimulus, so this is the correct answer.

Key Takeaway:
Remember that only the flawed portions of the stimulus need to be matched up in a Flawed Parallel Reasoning question. Here, the correct answer didn't explicitly spell out the intermediate conclusion as the stimulus did, but that didn't matter because the intermediate conclusion was valid.