LSAT 117 | Section 2 | Logical Reasoning: Q22

LR Question 22 Explanation

QUESTION TEXT: All the evidence so far gathered fits both …

QUESTION TYPE: Flawed Parallel Reasoning

CONCLUSION: This experiment will confirm one theory and disprove the other.

REASONING: All the evidence so far fits both theories. But the theories make different predictions about the planned experiment.

ANALYSIS: This is saying that if two theories make different predictions about one experiment, then the experiment’s result will tell us which theory is correct.

But that’s not necessarily true. A third possibility exists: both theories are wrong!

The argument assumes that one theory must survive. But both could fail.

The answer will match that flawed structure:

• Two conflicting options
• One will be proved true and the other will be proved false
• Ignores the possibility that both could be wrong

___________

1. If David and Jane often disagree about whether a tree is a beech or an elm, then at least one of them must be mistaken on at least some occasions. This conclusion can be true even if both are wrong. So this doesn’t assume one of them must be correct.
2. This is a question about whether evidence consistent with one view must be inconsistent with another view.
3. If David correctly identifies this one tree, then he is better overall at identifying trees. That’s a bad generalization from one case, which is a different flaw.
4. This isn’t flawed. David’s claim is either true or false. A complete examination of the forest really would either confirm or disprove that claim, so there’s no false dichotomy here.
5. CORRECT. The argument concludes Maria’s opinion will verify either David’s or Jane’s opinion. But what if Maria says the tree isn’t a beech nor an elm? It could be an oak. Like the stimulus, this ignores the possibility that both positions are wrong.