Logical reasoning PrepTest 109 · Section 4 · Question 21

Incorrect. Both discuss the consequences as being related to actions being good/bad (or at least considered as such), so there is no assumption about many properties being distinguishing factors.

Incorrect. None of the premises in either argument are about "most" actions of a certain type—only all or some.

Incorrect. The conditional premise in Terry's argument is general and applied to his society, which is the opposite of this answer. And all of Pat's statements deal with her society.

Correct. Argument or Facts:
Argument/Argument

Valid or Flawed:
Flawed/Flawed

Question Type:
Errors in Reasoning (emphasis on the plural!)

Stimulus Summary:
T: Action considered bad-some-Favorable consequences
Good action → Favorable consequences
Therefore - Action considered bad-some-Good action

P: Good action-some-not Favorable consequences
Action considered bad → not Favorable consequences
Therefore - Action considered bad-some-Good action

Answer Anticipation:
This question asks us to find an answer reflecting an error in Terry's reasoning and an error in Pat's reasoning. This could take the form of two separate flaws, or they could both be guilty of the same flaw. Looking at the answers, each presents a single flaw, so the two must be committing the same flaw—meaning we should identify the flaw in one of them and then quickly confirm its presence in the other.

Both of the arguments reach the same conclusion, and both use a some statement and a conditional statement ("only if"; "no actions"). So there's some type of conditional logic or quantifier flaw here.

Let's start by looking at Terry's argument. The overlap between the two statements is in the necessary condition of the conditional. We can combine a conditional with a some statement only when it's the sufficient condition that overlaps. If we were to reverse Terry's conditional premise, the argument would be valid, so Terry commits an illegal reversal.

Similarly, Pat's argument has the necessary condition of the conditional shared with the some statement. If we reverse her conditional, we end up with a valid argument.

Therefore, we should look for an answer describing an illegal reversal (treating a sufficient condition as necessary, or vice versa).

Answer Explanation:
This answer describes an illegal reversal—assuming that a necessary condition is sufficient. They both combine a conditional with a some statement that shares its necessary condition, but that's only a valid combination when it's the sufficient condition.

Key Takeaway:
This question is framed in a weird way, presenting two arguments that commit the same flaw. It's the only one that we can think of (most will feature two arguments with different flaws), so we wouldn't try to come up with an overall strategy for this specific version of an Errors in Reasoning question. Instead, our takeaway here is that it's important for a couple of questions on the LR section to be solid on quantifier inferences, so be sure to study up on that.

Incorrect. The stimulus discusses only actions that are good and that are considered bad, so this answer's reference to "other types" is out of scope.