#5 - Archaeologist: The earliest evidence of controlled fire

[Administrator]

Please post below with any questions!

[asalmen]

Why is the correct answer E and not A?

[Jonathan Evans]

Hi, Asalmen,

Let's take a look. We need to find an assumption (unstated belief) necessary for the conclusion to be valid. In other words, what is something the author clearly thinks but is not telling us? Start by clearly identifying and explaining the conclusion. The author argues that:

• The fact that the earliest evidence of the use of fire is 400,000-years-old casts doubt on the belief that humans had to master fire to migrate to Europe.

What idea is central to this claim? What does the author seem to believe without saying explicitly? What would we also have to know for this argument to make any sense?

Consider some possibilities. For instance, the author must believe that it is possible for evidence of the use of controlled fire to persist longer than 400,000 years. If evidence of the use of fire could only last 400,000 years, then the evidence cited would offer no support for the idea that there wasn't fire before 400,000 years ago; in turn, this evidence would then not cast doubt on the belief that humans had to master fire to migrate to Europe.

Note what happened there: we went through a brief thought-exercise, a version of the Assumption Negation Test™. We prephrased an assumption necessary for the argument to be valid. Then we considered what would happen if that assumption were negated. We saw that the conclusion made no sense without this essential assumption.

You can use the same process with the answer choices. Look at answer choice (A). Is it really essential that the humans who first mastered fire used it only for heat? Does the author have to believe this for her argument to make sense? What if these humans used the fire for cooking too? Could we still conclude that "the fact that the earliest evidence of the use of fire is 400,000-years-old casts doubt on the belief that humans had to master fire to migrate to Europe"?

Sure, why not? Maybe the humans used it for heat but also for cooking. They might have still not needed fire to move to Europe.

Now look at (E). Does this author have to believe that there were humans in Europe prior to 400,000 years ago for this argument to make sense? What happens if we logically negate this statement?

• There were not humans in Europe prior to 400,000 years ago.

What effect does this negated answer choice have on our claim that "the fact that the earliest evidence of the use of fire is 400,000-years-old casts doubt on the belief that humans had to master fire to migrate to Europe"?

In fact, it makes the claim nonsensical! If there weren't any humans in Europe prior to 400,000 years ago, of course there was no evidence of humans using fire in Europe before then. The evidence of fire would then have been contemporaneous with the arrival of humans to Europe, and, far from casting doubt on our belief, this evidence would in fact bolster the claim that control of fire was necessary for people to move to Europe. Given the idea that there weren't humans in Europe prior to 400,000 years ago, the conclusion totally falls apart.

Does this make sense? Thanks for the question!

Personally, I'm hoping that my knowledge of controlled use of fire will be enough to cover the cost of my next European vacation!

[JiminyC]

How is that an assumption though? What if the author is referring to people of other continents (aka Asia) and in order to migrate to Europe you must have controlled fire? If the first people to control fire in Europe were migrants 400,000 years ago, it would hold true that the earliest evidence of controlled fire in Europe was 400,000 years ago, yet there were not inhabitants in Europe prior to 400,000 years ago

[Adam Tyson]

What the author is claiming, JiminyC, is that mastery of fire was probably not a prerequisite to migration to Europe. In other words, people could have migrated before they mastered controlled fire. Why does he think so? His evidence is that controlled fire in Europe only goes back 400,000 years (or at least that is the earliest evidence found). So what? Why does that matter?

Your point is a good one. What if people existed in Europe originally, from the time of humans first existence, rather than migrating there from elsewhere? Humans could simply have evolved there. Then their presence would have nothing to do with migrations, and it is possible that the folks in Asia or Africa or elsewhere still could not migrate to Europe, and join the humans already there, until those folks mastered fire. The presence of people in Europe before controlled fire may not be all that helpful.

But consider the negation of answer E, and see what that does to the argument. If there were no humans present in Europe before 400,000 years ago, then the evidence tells us nothing about whether fire was a prerequisite for migration. The argument falls apart without the assumption that people were there before fire was controlled. Maybe it was a prerequisite after all? The earliest evidence of controlled fire would no longer cast doubt on that claim.

I think where you may be off track is that you are looking at the assumption as something that has to prove, or powerfully strengthen, the argument, rather than as something that the argument requires. Humans being present before fire was controlled does not prove that anyone migrated without fire, because we don't know if those people migrated. But assumptions don't have to help the argument, at least not much. Instead, assumptions have to be true IF the argument is to be seen as valid.

To use one of our most common examples for assumptions, consider the claim that I am a great tennis player. In order for that claim to be true, I must assume that I can hit the ball over the net. Hitting the ball over the net does nothing to prove that I am a great player, and it does virtually nothing to strengthen it. It's a tiny blip of evidence, barely worth considering. But what if it's not true? If I cannot hit the ball over the net, then clearly I am wrong about my greatness. The correct answer to this question has a similar effect - it doesn't do much to help the argument, perhaps, but it has to be true if the author's claim is to make any logical sense.

Take another look at it from that perspective and see if you like the answer any better now. Keep at it!

[LearntheLSAT]

Hello,

Is D wrong because it is too broad for this stimulus? I chose it twice, once during PT and during BR, but obviously I missed something. If my logic is correct, then I can see why E makes a more appropriate fit. I was trying to figure out some connection to heat to human migration though because I created a causal relationship:

CW (cold winters) -> Master fire

Is this not a causal relationship?

[Adam Tyson]

I think answer D is more conditional than causal, LearntheLSAT, although there does at least appear to be some implied causality there, that the need for heat was the cause of controlling fire. Certainly the position that the author is arguing AGAINST is a causal one, but his counter-argument is not. He is saying that migrating to a cold climate doesn't have to require controlled use of fire. It's anti-causal, or anti-conditional, rather than causal.

Consider the negation of answer D - what if humans would have learned to control fire even if they did NOT need it to deal with cold weather? Maybe for cooking, or for light at night, or to frighten predators away, or to make tools? Does that do anything to hurt the argument that humans did not need to control fire before they migrated to Europe?

Consider this simplification of the argument:

Premise: Controlled fire in Europe only goes back 400,000 years
Conclusion: So we didn't need to control fire in order to migrate there

What's missing? The assumption that someone migrated to Europe before 400,000 years ago, before they had learned to control fire. And that requires the further assumption that someone was actually IN Europe prior to 400,000 years ago. If nobody was there, then nobody had migrated there, and there is no longer any reason to believe that you can migrate there without controlling fire first. Heat has nothing to do with it!

[LawSchoolDream]

I suppose this question had me lost because I don't know when people first migrated to Europe? So I couldn't figure out between A and E?

[Robert Carroll]

LawSchoolDream,

I don't know either! The author never talked about it. That's why the argument is so bad. "Humans only had fire 400,000 years ago. So they didn't need fire to migrate to Europe." Huh?! How could that argument possibly work? They obviously had fire when they were using the fire that we have evidence of from 400,000 years ago. So when did they NOT have fire, but were still in Europe? If there's no point when they didn't have fire, but WERE in Europe, the argument makes no sense. Answer choice (E) provides that missing assumption.

Robert Carroll