Unplugged Practice Test: Logical Reasoning Set 3, Question 16 (Flaw)
Taking the test? Finish it first. This page shows the answer.
- Flaw questions ask you to name the reasoning error the argument commits, not to judge whether its conclusion is true.
- Before you read the choices, describe the argument's error in your own words. Most Flaw questions reward 1 of a small set of recurring patterns, so naming the pattern first keeps the trap answers from sounding right.
- Every question on this test is original, written to the same logical skeletons as real questions, and Steve checked every one himself before release.
The question
Preservation officer: Members of a landmark commission frequently vote to designate a building largely on grounds unrelated to the building itself, among them a reluctance to cross colleagues they will sit with for years and the standing of whoever brought the nomination forward. That costs preservation nothing at all, since pressures of the same sort operate on every body that decides by vote.
16. The preservation officer's argument is most vulnerable to criticism on the grounds that it
- (A)assumes that whether a practice defeats the aims of one enterprise turns on how widespread similar practices are elsewhere
- (B)assumes that grounds unrelated to a building are the only ones on which commissioners ever vote
- (C)disregards the chance that commissioners moved by such pressures still weigh a building's merits before voting
- (D)disregards the chance that many commissioners do not recognize how often such pressures decide their votes
- (E)assumes that a practice harmless to preservation must be harmless to every other enterprise
AWhy (A) is correct
The officer grants that commissioners often vote on grounds that have nothing to do with the building, colleagues they'll keep working with and the standing of whoever brought the nomination, then says this costs preservation nothing because the same pressures operate on every body that decides by vote. That move only works if whether a practice undermines one enterprise's goals depends on how common it is elsewhere, exactly the assumption (A) names. A pressure being universal to voting bodies doesn't show it leaves landmark preservation unharmed.
Why the other answers are wrong
BWhy (B) is wrong
(B) doesn't fit, since the officer says commissioners frequently vote on unrelated grounds, not that those are the only grounds they ever use.
CWhy (C) is wrong
(C) isn't the flaw tested here, since the officer's error is the prevalence-equals-harmless leap, not a claim about whether commissioners also weigh merit.
DWhy (D) is wrong
(D) misses too: nothing in the officer's reasoning turns on whether commissioners recognize these pressures.
EWhy (E) is wrong
(E) reverses the direction: the officer argues from prevalence elsewhere to harmlessness here, not from harmlessness here to harmlessness everywhere.
Common questions
What type of question is this?
Flaw. Flaw questions ask you to name the reasoning error the argument commits, not to judge whether its conclusion is true.
How do I get better at Flaw questions?
Before you read the choices, describe the argument's error in your own words. Most Flaw questions reward 1 of a small set of recurring patterns, so naming the pattern first keeps the trap answers from sounding right. The free LSAT cheat sheet lists the wrong-answer patterns to watch for on every type.
