Flawed Parallel ReasoningDiff: Medium
Logic Breakdown
Passage Summary: Since we haven't proven it was definitely campers and we haven't proven it was definitely lightning, we haven't proven it was one of those two things.
Conclusion: Investigators have not proven that the fire was caused by either campers or lightning.
Reasoning: Investigators have failed to prove that campers started the fire, and they have also failed to prove that lightning started the fire.
Analysis: This argument commits a classic error regarding the burden of proof and disjunctions. Just because you haven't proven 'A' individually and haven't proven 'B' individually doesn't mean you haven't proven 'A or B' as a set of possibilities. For example, if those were the only two possible causes, you might have proven it was one of them without knowing which. To match this flaw, look for an answer that says: 'We haven't proven X, and we haven't proven Y, so we haven't proven X or Y.'
Conclusion: Investigators have not proven that the fire was caused by either campers or lightning.
Reasoning: Investigators have failed to prove that campers started the fire, and they have also failed to prove that lightning started the fire.
Analysis: This argument commits a classic error regarding the burden of proof and disjunctions. Just because you haven't proven 'A' individually and haven't proven 'B' individually doesn't mean you haven't proven 'A or B' as a set of possibilities. For example, if those were the only two possible causes, you might have proven it was one of them without knowing which. To match this flaw, look for an answer that says: 'We haven't proven X, and we haven't proven Y, so we haven't proven X or Y.'
Passage Stimulus
Passage Redacted
Unlock Full Passage14.The flawed pattern of reasoning in which one of the following arguments most closely resembles the flawed pattern of reasoning in the argument above?
Correct Answer
A
It mirrors the structure: Kim has no reason to believe Sada will win and no reason to believe Brown will win; thus, no reason to believe that either Sada or Brown will win. Like the stimulus, it treats the lack of support for each option as if it were lack of support for their disjunction.
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