LSAT 90 - Section 4 - Question 07

This is a Necessary Assumption question.

The stimulus says recently discovered clay tablets from southern Egypt date to between 3,300 and 3,200 B.C. Though most of the tablets translated thus far are tax records, one of them appears to contain literary writing. All of this is premise supporting the conclusion.

And the conclusion is that these tablets challenge the widely held belief among historians that the Sumerian civilization in Mesopotamia was the first to create literature. So we used to think that the Sumerians were the first, and somehow these tablets challenge that, meaning the Egyptians predate the Sumerians. If you already spotted this assumption, you can just go hunting for the correct answer. But we’ll use process of elimination here.

Answer Choice (A) says most of the recently discovered tablets that have not yet been translated contain literary writing. So in the entire set of recently discovered tablets, there is a subset that has not yet been translated. And in that subset, most contain literary writing.

We do not need this to be true. We already have one of the tablets that contain literary writing and that is enough. Sure, having more would strengthen this argument, but we are just trying to find the necessary assumption. Running the negation test also helps. Say not most but rather just a few of the tablets contain literary writing. The argument does not fall apart.

Answer Choice (B) says every civilization that has kept tax records has also kept other written records. This is also not necessary. We are only talking about two civilizations, the Egyptian and the Sumerian. Why do we care if some other civilization like the Aztecs kept other written records? What does that have to do with this argument? Egypt still predates, or does not predate, the Sumerians in creating literature.

Correct Answer Choice (C) says historians generally believe that Sumerians did not create literature earlier than 3,300 B.C. This has to be true. Imagine if historians generally believed that the Sumerians did create literature earlier than 3,300 B.C., say 4,000 B.C. That is 6,000 years ago. And now we have this Egyptian tablet from 3,300 B.C., only 5,300 years old at best. How is this supposed to challenge the belief that Sumerians were the first to create literature? The Sumerians still predate the Egyptians by 700 years. That is why (C) is absolutely necessary.

Note that this question could have been way harder. Imagine if one of the other answer choices said historians generally believe that Sumerians first created literature between 2,800 B.C. and 2,700 B.C. This would be a super attractive answer choice. However, while this would certainly help the argument by definitively showing that Egyptian literature is older by about 600 years, it is not necessary. And you can see this is not necessary by changing the dates a bit, say 2,500 and 2,400 B.C. That would also help the argument. So it is not necessary that historians have to believe in the 2,800 to 2,700 B.C. date range.

Answer Choice (D) says some historians are skeptical about the authenticity of recently discovered tablets. This is not necessary. If anything, the skepticism only hurts the credibility of the argument. Necessary Assumption is part of the superset that we call Strengthening.

Answer Choice (E) says the Sumerian civilization arose sometime between 3,300 B.C. and 3,200 B.C. This is also not necessary. What if it instead arose between 2,800 and 2,700 B.C.? Falsifying, or negating, (E) does not ruin the argument. If anything, this version of falsification actually helps the argument. Egypt would clearly predate the Sumerians in this scenario because the Egyptian clay tablet would be dated to be 500 years older than the Sumerian civilization itself.