LSAT 90 - Section 2 - Question 03

This is an NA question.

The stimulus proceeds in order from premises to the conclusion. Bovine remains were found in a certain place back when that place had an arid (dry) climate. There were people present at that time in that region but no other large mammals. If there were natural sources of water available, there would also have been other large mammals. But we already know there were no other large mammals. We can contrapose to infer that there were no natural sources of water available.

The argument hence concludes that these bovines had been domesticated (people were providing it water) and the people there were no longer exclusively hunter-gatherers.

This sounds like a decent argument, right? If you think so, then you’re already supplying the missing assumption, that if they weren’t domesticated, they couldn’t have survived. But really, we don’t know that. Perhaps they were wild and crafty and survived by taking advantage of man-made water sources. That would be bad for the argument. So we do need to supply the assumption connecting the premises (arid climate, no natural water sources) to the conclusion (domestication).

This is what Correct Answer Choice (A) does. Translating the “unless,” (A) says that if the bovines weren’t domesticated, they were unlikely to exist in a region without natural sources of water. The premises fail the necessary condition (the bovines likely did exist), which allows us to infer the failure of the sufficient condition (the bovines were domesticated) as the conclusion. This connects the premises to the conclusion. More than that, it truly is necessary. If we deny this conditional relationship, we’re asserting that it’s possible for the bovines to be wild yet survive anyway in this arid region. That’s exactly the possibility that we contemplated above that would ruin the argument.

Answer Choice (B) says that domesticating animals is one of the first things that a society must do when transitioning from hunter-gatherer to agriculture. This is unnecessary. Why first? Why not second or third? Also notice that it’s trying to bridge the two concepts in the conclusion, that of “domestication” and that of “no longer exclusively hunter-gatherer.” But we don’t need to build that bridge. They are already connected by their definitions. Domestication necessarily implies no longer exclusively hunter-gatherer. A culture that practices domestication cannot be exclusively hunter-gatherer.

Answer Choice (C) says that other large mammals would have been able to inhabit this arid region with the help of humans. So, like what? Horses? That’s required? No, it’s not. Let’s imagine this were false. Even with the help of humans, this arid region could not have supported horses. Who cares? The argument is still as strong as it ever was.

Answer Choice (D) says no human culture can be a hybrid of agriculture and hunter-gatherer. So (D) is claiming that all human cultures must be exclusively either an agricultural society or else a hunter-gatherer society. You can’t do both. But that’s silly. It doesn’t affect the argument if there was a culture that both planted wheat and hunted meat. In fact, the conclusion in the stimulus claims that these people are a kind of hybrid culture.

Answer Choice (E) says that a domesticated cow doesn’t need as much water as a wild cow. This might strengthen the argument? Like their modest demand for water might help explain why humans were able to domesticate them in an arid climate. But it’s not necessary. Imagine this were false and the cows required the same amount of water, regardless of whether they were domesticated or wild. The argument would still be fine. It would just have been not as easy to domesticate them.