Logical reasoning PrepTest 144 · Section 2 · Question 19

Incorrect. This answer does describe an ad hominem flaw, but not the one present in the stimulus. The Politician doesn't rely on the leaders being members of a union to discredit them—he uses the fact that, as members of the union, they have a vested interest in making a certain argument to dismiss that argument. She also doesn't dismiss all of their viewpoints, just the one mentioned in the stimulus.

Incorrect. First, there's no indication that the union leaders' motivations are political. Second, even if they were, this answer is too broad in applying to anyone. There's also a term shift between the conclusion of the argument—rejecting an argument—and this answer—being an unreliable source of info.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Union leaders make a certain argument, but they have a vested interest in making it, so that argument should be rejected.

Answer Anticipation:
If the argument by the union leaders went over your head, no worries! There's actually no need to understand it to answer this question—it is, after all, asking about a flaw in the Politician's argument. As such, we should focus less on what the union says and more on the Politician's reason for rejecting their argument.

Looking at that portion of the stimulus, we see that the Politician doesn't actually address their argument at all. Instead, she goes after the union leaders, stating that they have a "vested interest" in making the argument that they're making. She doesn't provide any reason to believe they're wrong other than this biased motive. When someone goes after the person making the argument instead of the argument itself, that person is guilty of an ad hominem flaw.

Answer Explanation:
While it buries it under some language, this answer highlights the Politician's tactic of going after the union leaders vested interests ("circumstances potentially affecting the union leaders' argument") instead of the argument itself, and dismissing it solely for those reasons. This answer gets at the heart of an ad hominem flaw—ignoring the argument in favor of questioning the person making it.

Key Takeaway:
Ad hominem attacks are flawed because they don't address the actual argument. Someone can be biased, hypocritical, a criminal, uninformed . . . and still right. On the LSAT, always make sure that any rebuttal deals with the opposing argument itself and not the person making it.

Incorrect. Since the argument rejects the argument based on something true of those making it and not the argument itself, it's not assuming it's the only argument they'd make in favor of their view. The Politician's rebuttal, in fact, would (invalidly) apply to any argument they could make.

Incorrect. The stimulus always discusses the specific leaders making this argument, so it's not assuming anything about all union leaders.