LSAT 81, Logical Reasoning I, Q5, LSATHacks

LR Question 5 Explanation, by LSATHacks

QUESTION TEXT: Archaeologist: The earliest evidence of controlled fire…

QUESTION TYPE: Necessary Assumption

CONCLUSION: It is unlikely that early humans needed fire to move to Europe.

REASONING: We only have evidence of human controlled fire in Europe starting 400,000 years ago.

ANALYSIS: This argument is implying that fire was only used in Europe recently, and so humans must have been in Europe before fire was there.

But….the argument doesn’t actually say when humans arrived in Europe. So the necessary assumption is that they were in fact living in Europe before they used fire.

___________

1. It doesn’t matter why humans used fire. It only matters whether it was necessary.
   Negation: The humans who first used fire did not use fire only for heat but not cooking.
2. This may be true, but what does it matter? We don’t know what temperature level would make fire necessary.
   Negation: The climate in Europe was not much colder 400,000 years ago than it is today.
3. Occasional fire use isn’t significant. If fire is necessary, then you can’t migrate to a new land using only “occasional” fire. Also, this doesn’t tell us that these humans who occasionally used fire did so in Europe.
   Negation: Humans never took advantage of naturally occurring fires until 400,000 years ago.
4. The stimulus didn’t say that humans originally mastered fire in Europe. This answer is just trying to confuse you by taking two terms from the stimulus and joining them in a conditional statement. It’s perfectly possible that some humans in Africa mastered fire, but were not near Europe and so no other humans could have migrated to Europe.
   Negation: There are reasons for humans to master fire other than living in a cold climate.
5. CORRECT. The argument hinged on showing that humans were in Europe before fire was there. If humans did not go to Europe before fire, then maybe fire was necessary.
   Negation: Humans did not get to Europe until sometime more recent than 400,000 years ago.

Hi, I'm Graeme Blake

Founder of LSAThacks; I scored a 177 on the LSAT.

I created the LSAT Mastery Seminars, which are part of the Ultimate LSAT Prep Bundle

If you like the explanations you're reading I'm 100% confident you'll enjoy the courses. Satisfaction guaranteed.

---------
Updates:

For updates, sign up for my email list. I update whenever I have new posts.